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Brown, P.R. 1963. Algal limestones and associated sediments in the basal Purbeck of Dorset. Geological Magazine, 100, 565-573.

Brown, P.R. 1964. Petrography and origin of some upper Jurassic beds from Dorset, England. Journal of Sedimentary Petrology, 34, 254-269.

Brown, P.R. 1961. Petrology of the Lower and Middle Purbeck Beds of Dorset. Unpublished Ph.D. thesis, Liverpool University, 205 p.

Brown, P.R. 1963. Algal limestones and associated sediments in the basal Purbeck of Dorset. Geological Magasine, 100, 565-573.

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House, M.R. 1968. Purbeckian calcareous algae. In Dorset Natural History Reports - 1967 - Geology. Proceedings of Dorset Natural History and Archaeological Society for 1967. vol. 89, p.41-45.

Perry, C.T. 1992. Freshwater tufa stromatolites in the Lower Purbeck Beds (Upper Jurassic), Isle of Portland, Dorset. Programme and Abstracts, BSRG 1992, Southampton, 31st Annual Meeting of the British Sedimentological Research Group, 16-19 December 1992. 1 page only. Perry - University of Derby 1992 Graduate. Poster. Argues for freshwater origin of Caps of Portland. Classifies stromatolites on the degree of mineralization/biomineralization which they exhibit. This summarises much of what is included in Perry, C.T. unpublished 1993. See discussion of Bosence et al. 1987 re chironomids.

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Perry , C.T. 1994. Fresh-water tufa stromatolites in the basal Purbeck Formation (Upper Jurassic), Isle-of-Portland, Dorset. Geological Journal, 29, 119-135. Abstract: Recent interpretations of the tufaceous limestones from within the 'Caps Beds' on the Isle of Portland have suggested a depositional environment of intertidal flats and lagoons with typically higher than normal marine salinity levels, a stark contrast with earlier ideas of a freshwater origin. However, evidence is presented in this paper to show that these deposits are indeed most likely to be freshwater in origin. The micro-fabrics observed are typical of those seen in freshwater tufas forming at the present day, and contrast with those observed within intertidal/subtidal stromatolites. Furthermore, the Portland deposits lack syndepositional evaporite deposits, they lack recognizable intertidal deposits, and any lagoonal sediments observed are depositionally distinct from the tufas. Finally, the soil horizons observed are clear evidence of periodic subaerial exposure and isolation from marine influences. Four facies types are identified on Portland: (1) tufaceous limestone; (2) littoral grainstones; (3) subaerial stromatolites; and (4) paleosols. Each facies is repeated a number of times through the sequence, and evidence is presented to show that these formed in a marginal marine setting as a response to a series of minor transgressive (soils to freshwater lakes/lagoon to saline marine/lagoonal) and regressive events (saline marine/lagoonal to soils). The tufa stromatolite deposits themselves, which are often developed around cylindrical holes (representing former tree trunks and branches), are shown to have developed seasonally, by the precipitation of carbonate, due to microbial activity within the freshwater lake environment. Precipitation appears to have been most intense around tree bases (and any associated vegetation), where an active biofilm developed on the underlying soil substrate. Two distinct textures are recognized in this material: (1) micro-porous and (2) macro-porous. These developed together in a crudely laminated, semi-concentric pattern around the holes and together may represent a seasons growth of tufa. [This paper is particularly useful in providing detailed description and showing the unusual features of the Purbeck stromatolites. The present writer considers that the lack of a freshwater gastropod fauna, lack of low salinity ostracods, and the presence of pseudomorphs after gypsum in the equivalent strata (the Hard Cap) with stromatolites at the Fossil Forest is evidence against a freshwater origin. See West (1975) for details of high salinity evidence. See also discussion of Bosence et al. 1987 re chironomids]
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Pugh, M.E. 1968. Algae from the Lower Purbeck limestones of Dorset. Proceedings of the Geologists' Association, London, 79, 513-523. By Mary Pugh.
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Radoicic, R. 1958. The occurrence of calcareous algae in the upper Jurassic sediments of the neighbourhood of Lastra (Trebinje). Geological Bull. (Montenegro), 1958, vol. 2. (Translated 1962).

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Wilson, V. and Anderson, F. W. 1954. (Exhibition of algal growth-form in the British Palaeozoic and Jurassic rocks). Proceedings Geological Society, No. 1507, pp. xli-xlii.

"Algae", Cyanobacteria, Cyanophytes, Blue-greens, Stromatolites, Thrombolites - Analogues

Braithwaite , C.J.R. and Veysel Zedef. 1994. Living hydromagnesite stromatolites from Turkey. Sedimentary Geological , 92, 1-5. This is not on the Purbeck but is a useful analogue. Salda Golu - alkaline freshwater lake pH>9 in southern Turkey. The hydromagnesite stromatolites develop on fallen tree branches (cf. Purbeck fossil forests). No molluscs which might have included grazers. Magnesium and carbonate come from local ultramafic rocks.

Cornee , A., Dickman, M. and Busson, G. 1992. Laminated cyanobacterial mats in sediments of solar salt works: some sedimentological implications. Sedimentology, 39, 599-612. (Chironomid - p. 600, important - salinity controls on gastropod grazing, petees. Chironomids could tolerate up to almost 100 parts per thousand salinity. See discussion of Bosence and Perry publications)

Stromatolites (or Thrombolites) on Trees - Analogues

Braithwaite, C.J. R. and Veysel Zedef. 1994. Living hydromagnesite stromatolites from Turkey. Sedimentary Geology, 92, 1-5. (Salda Golu - alkaline freshwater lake pH>9 in southern Turkey. The hydromagnesite stromatolites develop on fallen tree branches (cf. Purbeck fossil forests). No molluscs which might have included grazers. Magnesium and carbonate may have come from local ultramafic rocks. See also Dead Sea Literature - Neev. )

Amphibians

Go to Purbeck Amphibians

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Analogues - General

Anadon, P., De Deckker, P. & Julia, R. 1986. The Pleistocene lake deposits of the N.E. Baza Basin (Spain): salinity variation and ostracod succession. Hydrobiologia, 143, 199-208.

Anadon, P. Cabrera, L. and Kelts, K. 1991. Lacustrine Facies Analysis. I.A.S. Special Publication No. 13, Blackwell Scientific Publications, Oxford, £40, ISBN - 10632-03149-2. Includes Platt, N.H. and Wright, V.P. 1991. Lacustrine carbonate facies models, facies distributions and hydrocarbon aspects. Pp. 57-74. in Anadon, P. Cabrera, L. and Kelts, K. 1991. Lacustrine Facies Analysis. International Association of Sedimentologists, Special Publication No. 13, Blackwell Scientific Publications, Oxford, ISBN - 10632-03149-2.

Andrews, J. E. and Walton, W. 1990. Depositional environments within Middle Jurassic oyster-dominated lagoons: an integrated litho-, bio- and palynofacies study of the Duntulm Formation (Great Estuarine Group, Inner Hebrides). Trans. Roy. Society Edinburgh: Earth Sciences, 81, 1-22. (very similar facies to those of the Purbecks)

Cornee, A., Dickman, M. and Busson, G. 1992. Laminated cyanobacterial mats in sediments of solar salt works: some sedimentological implications. Sedimentology, 39, 599-612. Chironomid - p. 600, - salinity controls on gastropod grazing, petees. Chironomids could tolerate up to almost 100 parts per thousand salinity. See the Bosence and Perry freshwater arguments about the Portland tufa.

Gasse, F., Fontes, J.C. Plaziat, J.C., Carbonel, P., Kaczmarska, I, De Deckker, P., Soulie-Marsche, I., Callot, Y. and Dupeuble, P.A. 1987. Biological remains, geochemistry and stable isotopes for the reconstruction of environmental and hydrological changes in the Holocene lakes from North Sahara. Palaeogeography, Palaeoclimatology, Palaeoecology, 60, 1-46. Elsevier, Amsterdam, Oxford, New York, 270pp. ( Purbeck -Lake Analogue, Purbeck - Protocardia analogue, Purbeck - ostracod palaeosalinity, Purbeck - chara analogue ).

Platt, N.H. and Wright, V.P. 1991. Lacustrine carbonate facies models, facies distributions and hydrocarbon aspects. Pp. 57-74. in Anadon, P. Cabrera, L. and Kelts, K. 1991. Lacustrine Facies Analysis. International Association of Sedimentologists. Special Publication No. 13, Blackwell Scientific Publications, Oxford. ISBN - 10632-03149-2.

Aragonite

El-Shahat, A. 1977. Petrography and Geochemistry of a Limestone-Shale Sequence with Early and Late Lithification: the Middle Purbeck of Dorset, England. Unpublished Ph.D. thesis, Southampton University, 358pp. [Aragonitic bivalves preserved in some cases. Diagenesis in others]

El-Shahat, A. & West, I.M. 1983. Early and late lithification of aragonitic bivalve beds in the Purbeck Formation (Upper Jurassic-Lower Cretaceous) of southern England. Sedimentary Geology, 35, 15-41.

Fuchtbauer, H. and Goldschmidt, H. 1964. Aragonitische Lumachellen im bituminosen Wealden des Emslandes. Beitr. Mineral. Petrogr., 10, 184-197. (Aragonitic bivalve beds like those in the Chief Beef Member of the Dorset Coast, UK)
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Maliva, R.G. and Dickson, J.A.D. 1992. The mechanism of skeletal aragonite neomorphism - evidence from neomorphosed mollusks from the Upper Purbeck Formation (Late Jurassic - Early Cretaceous), southern England. Sedimentary Geology, 76, 221-232. Abstract: The trace element geochemistry and microtextures of neomorphosed mollusks from the upper Purbeck Formation (Late Jurassic-Early Cretaceous) of southern England suggest that calcite replacement of aragonite occurs by a force of crystallization-driven mechanism similar to that of non-polymorphic skeletal carbonate replacement reactions, such as silicification. The Purbeck neomorphic calcites are substantially enriched in Mg, Mn, and Fe, and depleted in Sr compared to skeletal aragonite indicating that the neomorphic reaction zones were not chemically isolated from the bulk pore waters to a significant degree. Neomorphic calcite microtextures are fundamentally similar to the replacement microtextures of silicified and celestite-replaced fossils, in terms of the degree and style of preservation of traces of skeletal microtextures in authigenic crystals and the relationships of authigenic crystal morphology and crystallographic orientation to shell microtexture. The neomorphic replacement of aragonite by calcite differs from most non-polymorphic replacement reactions in that the calcite cannibalizes aragonite. Decreases in the intraskeletal pore water calcium carbonate ion activity product caused by calcite precipitation results in aragonite dissolution adjacent to aragonite-calcite contacts (i.e., chalkification) in some fossils. Chalkification does not occur in non-polymorphic replacements of skeletal carbonate.

Aylesbury Area, Bugle Pit, Quainton, Brill etc. (Buckinghamshire)

Cox, B.M., Gallois, R.W. and Sumbler, M.G. 1994. The stratigraphy of the BGS Hartwell Borehole, near Aylesbury, Buckingshire. Proceedings Geological Association, 105, 209-224.

Mitchell, J. 1834. On the strata of Quainton and Brill in Buckinghamshire. London and Edinburgh Philosophical Magazine 4 (1), 148-149 (see page 149 re. reptiles).

Phillips, 1871. The Geology of Oxford and the Valley of the Thames. Oxford: Clarendon, 25 + 529 pp.

Beef (Fibrous Calcite - Cone-In-Cone)

(Commonly associated in various formations with diagenesis of aragonite in the presence of organic matter and under significant burial. Occurs in the Purbecks in organic-rich units with aragonitic bivalves)

El-Shahat, A. and West, I.M. 1983. Early and late lithification of some aragonitic bivalve beds in the Purbeck Formation (Upper Jurassic - Lower Cretaceous) of southern England. Sedimentary Geology., 35, l5-4l.

Marshall, J. D. 1982. Isotopic composition of displacive fibrous calcite veins: reversal in pore-water composition trends during burial diagenesis. Journal of Sedimentary Petrology., 52, 0615-0630.

Bibliographies

Thomas, J. and Ensom, P. 1989. Bibliography and Index of Dorset Geology (most Dorset oil references listed). Dorset Natural History and Archaeological Society, Dorchester, Dorset, 102p. see p.96 for index. (Many useful Purbeck references. Being updated and put on computer database by Dr Gallois)

Biomarkers, Organic Etc.

Hill, A.F.M. 1993. Biomarkers indicating enhanced salinity have been found by Alan Hill (Dept of Geology, Univ. of Aberdeen) in specimen LP371 from the Mountfield Mine. Pursuing research on biomarkers in hypersaline shales.

Bivalves

See also Molluscs - General

Casey, R. 1952. Some genera and subgenera, mainly new of Mesozoic heterodont lammellibranchs. Proc. Malac. Soc. London, 29, 121-176.

Casey, R. 1955. The pelecypod superfamily Corbiculacea and its distribution in the British Mesozoic. Journal Washington Academy of Science., 45, No. 12, Dec. 1955. (Purbeck bivalves)

Casey, R. 1955. The Neomiodontidae, a new family of the Arcticacea (Pelecypoda). Proceedings of the Malacological Society of London, vol. 31, parts 5 and 6, 208-222. (Purbeck Neomiodon etc)

Kelly, S.R.A. 1988. Laevitrigonia cineris sp. nov., a bivalve from near the Jurassic-Cretaceous boundary in the Durlston Formation (Purbeck Limestone Group) of Dorset. Proceedings of Dorset Natural History and Archaeological Society, 109, 113-116.

Morter, A.A. 1984. Purbeck-Wealden Beds mollusca and their relationship to ostracod biostratigraphy, stratigraphical correlation and palaeoecology in the Weald and adjacent areas. Proceedings of the Geologists Association., 95, 217-126.

Bivalve Beds (Shell-Beds, Shell Beds, Biosparrudites)

Allen, J.R.L. 1990. Transport- Hydrodynamics. In Briggs, D. E.G. and Crowther, P.R. eds. Palaeobiology: A Synthesis. Blackwell Scientitic Publications, Oxford, 227-230. (Wave action produces vertical nest and rosette biofabrics - see Fig. 2 for photo. Analogue - not direct ref to Purbecks)

Nagle, J.S. 1967. Wave and current orientation of shells. Journal Sedimentary Petrology., 37, 1124-1138. ( Purbeck analogue - not a direct Purbeck reference)

Radley, J.D. 1996. Research in progress: biostratinomic investigations of shell beds in the Purbeck Formation. Proceedings of Dorset Natural History and Archaeological Society, for 1995. vol 117, 154-155.

Wakefield, M.I. 1995. Ostracod biostratinomy at lagoonal shorelines: examples from the Great Estuarine Group, Middle Jurassic, Scotland. Proceedings of the Geologists' Association., 106, 211-218. ( Some discussion of Great Estuarine bivalve beds with references. Stacked Neomiodon and Unio. Nest and rosette biofabrics. Concave up out of turbulent flows and concave down from constant reworking on a high friction substratum (Kidwell and Holland, 1991). Vertically orientated oyster valves in hemispherical accumulations 20 - 30 cm in diam occur in littoral and intertidal areas according to Grinnel (1974) and Sanderson and Donovan (1974). "Cup in cup" biofabrics. )

" Black Pebbles " - Black Limestone Pebbles

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Blasi , H. 1980. Die Ablagerungsverhaeltrusse im "Portlandien" des Schweizerischen und Franzoesischen Juras. Ph.D. Thesis, University of Bern. 151p.

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Carozzi, A. 1948. Etude Stratigraphique et Micrographique du Purbeckien du Jura Suisse. Faculte des Sciences, Universite de Geneve, 175 pp. Stratigraphic and Micrographic Study of the Purbeckian of the Swiss Jura. Thesis presented at the Faculty of Sciences at Geneva University for degree of Doctor of Science in Geology and Mineralogy. Thesis No. 1122. This work is in printed and published paperback book format. [This is a classic, early, petrographic study of the Purbeck Formation, with quantitative data. Extract (which I have translated from the French): "The Purbeckian of the Swiss Jura presents two palaeogeographic domains that are quite distinct, already in part delimited by Maillard. The most extensive is the domain of the Lower Dolomitic Beds which covers the Vaudois Jura and the southern part of the Neuchatelois Jura and the Jura Bernois Jura. From the bottom to top there are 1. The Lower Dolomitic Beds (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), and 3. Upper Brackish or Upper Marine (Upper Purbeck)...
To the north of this zone in the heart of the Neuchatelois Jura is the domain of the marls with gypsum. The type succession is from bottom to top: 1. Marls with Gypsum (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), Upper Brackish or Marine Beds (Upper Purbeck)."
[A variety of interesting Purbeck topics are discussed including the Black Pebbles, the multicoloured breccio-conglomerates, the source of Mg, the charophytes, ostracods, the grumeleux limestones (also common in Dorset), the dolomites (cf. the Lower Purbeck dolomitic marls of Dorset), pelletoidal limestones ("pseudo-ooliths"), microbreccias, cargneules, celestite, gastropods, Dasycladiaceans (not present in Dorset), cylces of sedimentation, and faecal pellets. It has many graphic logs and maps and a good bibliography of the older Purbeck literature, much of which is not listed here. An important aspect is that Carozzi related Purbeck facies to palaeotectonics, with the dolomite facies of the Lower Purbeck girdling the gypsum facies which mostly occurs on the structural highs. The Dorset Purbeck is also, of course, affected by palaeotectonics - the well-known, Late Kimmerian. However, thickness variations are rather most noticeable in Dorset than the facies variations. Carozzi does not discuss the Dorset succession, but his work is useful for comparative purposes. Carozzi's thesis is an old classic and recommended reading for Dorset Purbeck enthusiasts.]

Cotillon, P. 1960. Caracteres petrographique et genese des galets noir observes dans une coupe des "Calcaires blancs" de Provence (Jurassique superieur-Cretace inferieur). C.R. Soc. Geol. France, 7, 170-171.

Francis, J.E. 1983. The Fossil Forests of the Basal Purbeck Formation (Upper Jurassic) of Dorset, Southern England. Unpublished Ph.D. Thesis, University of Southampton. (Very good work on Protocupressinoxylon purbeckensis and the palaeosols etc. )

Francis, J.E. 1986. The calcareous paleosols of the basal Purbeck Formation (Upper Jurassic), southern England. 112-138 in Wright, V.P. 1986. Paleosols: Their Recognition and Interpretation. Blackwell Scientific Publications, Oxford. 315p. (The Great Dirt Bed etc with fossil trees).

Grose, J.A. 1988. Origin of black pebbles from the Tithonian/Berriasian of the southern French Jura: still no solution? Abstract British Sedimentological Research Group, 1988, Cambridge, no page numbers.

Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. Milankovitch cycles found by Fast Fourier Transform. Role of glacio-eustasy - see also Frakes and Francis 1988, Nature. Cyclic carbonate deposition. Sierra del Pozo region, southeast Spain, near the coast, north-east of Granada. Black pebbles. Evaporites. Birdseyes. Del 13C and del 18 O isotope data. Sr ppm. Sr high in subtidal facies. Sedimentation rate 12-15 cm per 1000 yrs (ie. about 0.13 mm per annum).

Platt, N.H. 1991. Lacustrine carbonates and pedogenesis: sedimentology and origin of palustrine deposits from the Early Cretaceous Rupelo Formation, W. Cameros Basin, N. Spain. Reprinted from Sedimentology, 1989, 665-684. Pages 323-342 in the present book. In: Wright, V.P. and Tucker, M.E. (1991) Calcretes. Int. Ass. Sedimentol., Reprint Series, 2, 352. Blackwell Scientific Publications. Oxford. Charophytes, ostracods, gastropods and rare vertebrates. Silicified evaporites found near the top of the sequence. Stable isotope analysis. del 13C for -7 to -11 and del 18 O from -3 to -7.5. Palustrine limestones formed through pedogenic modification of lake carbonate. Low gradient, low energy, unstratified lake. Berriasian. Dark intraclasts like black pebbles.

Strasser, A. and Davaud, E. 1982. Les croutes calcaires (calcretes) du Purbeckien du Mont-Saleve (Haut-Savoie, France). Eclogae Geol. Helv., 75, 287-301.

Strasser, A. and Davaud, E. 1983. Black pebbles of the Purbeckian (Swiss and French Jura): lithology, geochemistry and origin. Eclogae Geol. Helv., 76, 551-580.

Vera, J.A. and Jimenez de Cisnero, C. 1993. Palaeogeographic significance of black pebbles (Lower Cretaceous, Prebetic, southern Spain). Palaeo, Palaeo, Palaeo, 102, 89-102. Blackening by forest fires - isotope evidence.

" Black Pebbles " - Analogues

Ward, W.C., Folk, R.L. and Wilson, J.L. 1970,. Blackening of eolianite and caliche adjacent to saline lakes, Isla Mujeres, Quintana Roo, Mexico. Journal of Sedimentary Petrology, 40, 548 - 555.

Boreholes

House , M.R. 1961. The structure of the Weymouth Anticline. Proceedings of the Geologists. Association, 72, 221-238. (Chaldon Herring Boreholes of B.P. Purbeck is more than 185 ft thick but no details are given. )

See also papers on the Arreton Boreholes of the Isle of Wight and the Warlingham Borehole, Surrey (Shearman). Purbeck was present in Hoe No 1 Borehole, Hampshire but there is no publication. Absent in many oil company boreholes (eg.Wytch Farm) because they are drilled on structural highs and the Purbecks are cut out by Late Kimmerian unconformity.

Broken Beds - Breccia

Limestone breccia with porous carbonate matrix, some lutecite chert with pseudomorphs after gypsum, some celestite and other relics of evaporites. The porous carbonate matrix is calcitised anhydrite. With similarities to rahwacke and cargneule but oligomict. Contains small folds but rarely slickensides. Ostracodal limestone blocks in the upper part.

Arkell, W.J. 1938. Three tectonic problems of the Lulworth District: studies on the middle limb of the Purbeck Fold. Quarterly Journal of the Geological Society of London, 94, 1-54. Discussion on the evidence of tectonism within the Broken Beds. Direction of movement of overlying strata which he suggested is a controversial matter (probably wrong!).

Arkell , W.J. 1940. Dorset Geology, 1930-1940. Proceedings of Dorset Natural History and Archaeological Society., 61, 117-135.

Arkell, W.J. 1947. The Geology of the Country around Weymouth, Swanage, Corfe and Lulworth. Memoir of the Geological Survey Great Britain, 386 pp. With Wright, C.W.and Melville, R.V. 2nd edition - 1952 with Addenda and Corrigenda.

Hollingworth, S.E. 1938. The Purbeck Broken Beds. Geol.ogical Magasine., 75, 330-332. Early ideas on former evaporites.

Salter, D.L. and West, I.M., 1965. Calciostrontianite in the basal Purbeck Beds of Durlston Head, Dorset. Min. Mag. 35, 146-150. Calciostrontianite from alteration of celestite in the Broken Beds.

Strahan, A. 1898. The Geology of the Isle of Purbeck and Weymouth. Memoirs of the Geological Survey, England and Wales. 278pp. (Old classic)

West, I.M., 1960. On the occurrence of celestine on the Caps and Broken Beds at Durlston Head, Dorset. Proc. Geol. Assoc. 71, 391-401. (Strontium minerals - first definate evidence of former evaporites in the Broken Beds)

West, I.M., 1964. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Proceedings of Yorkshire Geological Society. 34, 315-330. Petrographic evidence of vanished evaporites in the Broken Beds.

West, I.M., 1965. Macrocell structure and enterolithic veins in British Purbeck gypsum and anhydrite. Proceedings Yorkshire Geological Society, 35, 47-58.

West, I.M., Shearman, D.J. and Pugh, M.E., 1969. Whitsun Field Meeting in the Weymouth Area, 1966. Proceedings of the Geologists' Association., 80, 331-340. (Some discussion of various Purbeck facies, particularly the Broken Beds.)

West, I.M., 1969. Contribution in:International Field Symposium on the British Jurassic; Guide for Dorset and South Somerset. Ed. H.S. Torrens, A60-61.

West, I.M., 1973. Vanished evaporites - significance of strontium minerals. Journal of Sedimentary Petrology., 43, 278-279. (Use of the relatively insoluble strontium mineral for indication the former presence of calcium sulphate. Used with lutecite and pseudomorphs etc)

West, I.M., 1974. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Reprinted in Kirkland and Evans (Ed.): Marine Evaporites, Origin, Diagenesis and Geochemistry.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium "Sedimentation Jurassique W. Europeen." A.S.F. Publication Speciale, No.1, Mars 1979. 407-416. (Basal Purbeck evaporites and special type of sabkha cycles)

Broken Beds Analogues - Evaporites Breccias etc of Some Other Formations

Bell, C.M. 1989. Saline lake carbonates within an Upper Jurassic -Lower Cretaceous red sequence in the Atacama region of northern Chile. Sedimentology, 36, 651-663. The laterally extensive, 3 m thick, Codocedo Limestone Member within red beds of the Upper Jurassic - Lower Cretaceou Quebrada Monardes Formation in the Atacama region of northern Chile. Vertical accretion within a perenial saline lake. A few dinosaur bones and silicified tree trunks at one location. Centimetre-scale beds of evaporitic gypsum, anhydrite and halite now extensively replaced by calcite, chalcedony and quartz. Geodes and gypsum pseudomorphs in the overlying siltstone and sandstone. Brecciated zones occur (cf. Purbeck Broken Beds). Net-texture, lutecite, pseudomorphs after anhydrite. Laminites. Miliolid foraminifera. Association of folds with brecciation. Muller, Schmidt and Briegel (1981) noted that anydrite begins to deform and flow under geologically reasonable strain rates at 150 and 180° C. These temperatures are normally only reached at depths of 4-6 km but in the Codocedo Member, possibly with an overburden of no more than 1 km, a much higher geothermal gradient is suggested by the interstratified lava flows.

De Putter, T. 1990. The Corenne borehole (Dinant Basin, Belg ium): 100 meters of Upper Visean limestone breccia. 13th Int. Sed. Congr. Nottingham, Posters, 60-62. (published abstracts of posters).

Ford, D.C. 1989. Palaeokarst of Canada. pp. 313-336 in Bosak, P., Ford, D.C., Glazek, J. and Horacek, I. (eds.), Paleokarst: A Systematic and Regional Review. Elsevier, Amsterdam. 725pp. Devonian Bear Rock Formation of northwestern Canada - about 200m of limestone, dolomite, gypsum, anhydrite breccia - p.319 - foremost Canadian example of a solution breccia.

Palmer, M.V. & Palmer, A.N. 1989. Palaeokarst of the United States. pp. 337- 363 in: Bosak, P., Ford, D.C., Glazek, J. and Horacek, I. (eds.), Paleokarst: A Systematic and Regional Review. Elsevier, Amsterdam. 725pp. (Evaporite solution - Silurian and Devonian in Michigan - p. 356.)

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Buckinghamshire

Ambrose, K. 1989. Geological notes and local details for 1:10,000 sheet SP 60 NE (Thame and Haddenham); part of 1:50,000 sheet 237 (Thame). Technical Reports, Onshore Geology Series, WA/89/68. 24p.

Arkell, W.J. 1947. The Geology of Oxford. Clarendon Press, Oxford, vi + 267pp.

Davies, A.M. 1899. Contributions to the geology of the Thame Valley. Proceedings of the Geologists' Association , 16, 15-58.

Hudleston, W.H. 1887. Excursion to Aylesbury. Proceedings of the Geologists' Asssociation., 10, 166-172.

Lake, R.D. 1989. Geological notes and local details for 1:10,000 sheet SP 70 NW (Thame and Haddenham); part of 1:50,000 sheet 237 (Thame). Technical Reports, Onshore Geology Series, WA/89/68. 14p.

McKerrow, W. S. and Baden-Powell, D.F.W. 1953. Easter Field Meeting 1952. The Jurassic Rocks of Oxfordshire and their superficial deposits. Proceedings of the Geologists' Association., 64, 88-98.

Merrett, E.A. 1924. Ostracods found in the Purbeck Beds of the Vale of Aylesbury. Geological Magasine., 61, 233-238.

Radley, J. 198? Purbeck and Portland Gastropods. M.Sc. Thesis. True low salinity gastropod faunas in virtual evolutionary stasis since their appearance in the Jurassic. (Much Buckinghamshire Purbeck information . Micromorphic gastropod faunas, of algal meadows ;.Valvata, Hydrobia, Bathrotomaria, Aylesbury, Creamy Limestones, Chilmark Tisbury Ragstones, Shotover)

Radley, J.D. 1991. Palaeoecology and deposition of Portlandian (Upper Jurassic) strata at the Bugle Pit, Hartwell, Buckinghamshire. Proc. Geol. Assoc., 102, 241-249. (New Bugle Pit section exposed nearly 4 m of strata from near the top of the Creamy Limestones and through sediments of the overlying Purbeck Limestone Formation. Discussion of Whitchurch Sands - early Cretaceous or even late Jurassic. Purbeck sequence described - bed 9 is green ostracodal micrite. Stromatolites in bed 17. Thin tabular vugs in the underlying bed. Good source for references to earlier work )

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Building Stone (Purbeck)

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Arkell, W.J. 1945. The names of the strata in the Purbeck and Portland stone quarries. Proceedings of Dorset Natural History and Archaeological Society, 66, 158-168.

Arkell, W.J. and Tomkieff, S.T. 1953. English Rock Terms. Oxford, 139p. [Origins of the names of some named Purbeck beds - quarrymen's terms].
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Benfield, E. 1948. Purbeck Shop; A Stoneworker's Story of Stone. With an Introduction by Professor A.E. Richardson, A.R.A., F.R.I.B.A. Cambridge University Press. 172pp.

Benfield, E. 1990. Purbeck Shop. A Stoneworker's Story of Stone. Introduction by Brian Bugler. Ensign. [by Eric Benfield].
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Leach, R. 1975. An Investigation into the Use of Purbeck Marble in Medieval England. Harrison.
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Leary, E. 1983. The Building Limestones of the British Isles. Building Research Establishment Report. H.M.S.O. London, 91p.
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Suttle, J. 1993. Suttle Quarries. In Purbeck Stone near Swanage, Dorset. Colour brochure. [Riven New Vein, Sawn, Grub, New Vein etc.]
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Thomas, J. 1998.Discover Dorset: Stone Quarrying. The Dovecote Press Ltd., Stanbridge, Wimborne, Dorset. 79pp. Paperback. £4.95p. ISBN 1 874336 61 X. Stone quarrying is the most important of Dorset's traditional industries, with a history that reaches back to Roman times. The limestones from the Isles of Purbeck and Portland are amongst the most famous of all building stones, but elsewhere in the county there were once thousands of smaller quarries providing stone for the surrounding region. Their legacy lives on in Dorset's parish churches, country houses, farmhouses and cottages - even whole villages, giving each area its own distinctive character. Jurassic limestones, the heathstones, sandstones and Greensand - even flint and chalk - all have combined to the architectural patchwork that makes Dorset so attractive. (from the back cover). [Pp 55-64 - on Purbeck limestone with details of buildings using it.]
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West, I.M., Anderson, F.W. and Faulkner, P.A., 1975. The Stone: Catalogue. In Platt . Excavations of Medieval Southampton. 304-314.

(See also - The Use of Purbeck Marble in Mediaeval Times etc.)

Calciostrontianite

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Salter, D.L. and West, I.M., 1965. Calciostrontianite in the basal Purbeck Beds of Durlston Head, Dorset. Mineralogical Magazine, 35, 146-150.
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West, I.M., 1960. On the occurrence of celestine on the Caps and Broken Beds at Durlston Head, Dorset. Proceedings of the Geologists' Association, 71, 391-401.

Calcrete (Caliche)

Andrews, J.E. 1988. Soil-zone microfabrics in calcrete and in desiccation cracks from the Upper Jurassic Purbeck Formation of Dorset. Geological Journal, 23, 261-270. (Alveolar septal structure, needle fibre, desiccation cracks, calcrete.)

Francis, J.E. 1983. The Fossil Forests of the Basal Purbeck Formation (Upper Jurassic) of Dorset, Southern England. Ph.D. Thesis (unpublished), University of Southampton.

Perry, C.T. 1994. Freshwater tufa stromatolites in the Lower Purbeck Beds (Upper Jurassic), Isle of Portland, Dorset. Geological Journal, 29, 1129-135. (Controversial - disputed - unpublished letter of IMW on file. Evidence against freshwater origin) An abstract has been published as Perry, 1992.

Pugh, M.E. 1968. Algae from the Lower Purbeck limestones of Dorset. Proc. Geol. Assoc., 79, 513-523.

Celestite, Celestine

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Carozzi, A. 1948. Etude Stratigraphique et Micrographique du Purbeckien du Jura Suisse. Faculte des Sciences, Universite de Geneve, 175 pp. Stratigraphic and Micrographic Study of the Purbeckian of the Swiss Jura. Thesis presented at the Faculty of Sciences at Geneva University for degree of Doctor of Science in Geology and Mineralogy. Thesis No. 1122. This work is in printed and published paperback book format. [This is a classic, early, petrographic study of the Purbeck Formation, with quantitative data. Extract (which I have translated from the French): "The Purbeckian of the Swiss Jura presents two palaeogeographic domains that are quite distinct, already in part delimited by Maillard. The most extensive is the domain of the Lower Dolomitic Beds which covers the Vaudois Jura and the southern part of the Neuchatelois Jura and the Jura Bernois Jura. From the bottom to top there are 1. The Lower Dolomitic Beds (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), and 3. Upper Brackish or Upper Marine (Upper Purbeck)...
To the north of this zone in the heart of the Neuchatelois Jura is the domain of the marls with gypsum. The type succession is from bottom to top: 1. Marls with Gypsum (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), Upper Brackish or Marine Beds (Upper Purbeck)."
[A variety of interesting Purbeck topics are discussed including the Black Pebbles, the multicoloured breccio-conglomerates, the source of Mg, the charophytes, ostracods, the grumeleux limestones (also common in Dorset), the dolomites (cf. the Lower Purbeck dolomitic marls of Dorset), pelletoidal limestones ("pseudo-ooliths"), microbreccias, cargneules, celestite, gastropods, Dasycladiaceans (not present in Dorset), cylces of sedimentation, and faecal pellets. It has many graphic logs and maps and a good bibliography of the older Purbeck literature, much of which is not listed here. An important aspect is that Carozzi related Purbeck facies to palaeotectonics, with the dolomite facies of the Lower Purbeck girdling the gypsum facies which mostly occurs on the structural highs. The Dorset Purbeck is also, of course, affected by palaeotectonics - the well-known, Late Kimmerian. However, thickness variations are rather most noticeable in Dorset than the facies variations. Carozzi does not discuss the Dorset succession, but his work is useful for comparative purposes. Carozzi's thesis is an old classic and recommended reading for Dorset Purbeck enthusiasts.]

Salter, D.L. and West, I.M., 1965. Calciostrontianite in the basal Purbeck Beds of Durlston Head, Dorset. Min. Mag. 35, 146-150.

West, I.M., 1960. On the occurrence of celestine in the Caps and Broken Beds at Durlston Head, Dorset. Proceedings of the Geologists' Association, London. 71, 391-401.

West, I.M. 1973. Vanished evaporites - significance of strontium minerals. Journal of Sedimentary Petrology, 43, 278-279.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association., 86, 205-225.

Chalbury Camp

Francis, J.E. 1983. The Fossil Forests of the Basal Purbeck Formation (Upper Jurassic) of Dorset, Southern England. Ph.D. Thesis (unpublished), University of Southampton. (Tree remains at Chalbury)

Francis, J.E. 1986. The calcareous paleosols of the basal Purbeck Formation (Upper Jurassic), southern England. 112-138 in Wright, V.P. 1986. Paleosols: Their Recognition and Interpretation. Blackwell Scientific Publications, Oxford. 315p. (Tree with side branch shown p. 116.)

Charophytes (Charales)

Allen, G.O. 1950. British Stoneworts (Charophyta). Haslemere Natural History Society. Arbroath, T. Buncle and Co. Ltd. 52 pp.

Barker, D., Brown, C.E., Bugg, S.C. and Costin, J. 1975. Ostracods, land plants and charales of the basal Purbeck Beds of Portesham Quarry. Palaeontology, 18, 419-436.

Burne, R.V., Bauld, J. and De Deckker, P. 1980. Saline lake charophytes and their geological significance. Journal of Sedimentary Petrology, 50, 281-293. Abstract: Charophytes are found in some empheral saline lakes in Australia. Healthy green charophytes, bearing oogonia, are frequently observed at salinities ca. 1-2 times that of seawater. Field observations of salinity tolerance are confirmed by experiments which demonstrate photosynthetic 14 C-carbon dioxide fixation at these salinities. The lakes containing these charophytes have various hydrological settings but all are influenced by inputs of continental groundwater of varying salinity. Different evaporite minerals are deposited depending upon local desiccation-evaporation balances. In coastal lagoons adjacent to the Coorong, charophytes are found associated with calcite, aragonite and protodolomite while in the continental lakes around northern Spencer Gulf the observed associated are with gypsum and halite. Lake deposits containing charophyte oogonia and discoidal gypsum provide a recent analog for some ancient evaporite units which are not adequately explained by the arid, coastal marine evaporite model based on the present-day Persian Gulf sabkhas. For example, the Purbeckian evaporites of Dorset (England) and the Tertiary evaporites of the Paris Basin (France) both contain charophyte- and evaporite-bearing units which are similar to the deposits of these Recent Australian lakes. We suggest that sediments containing associations of charophyte oogonia and evaporites formed as a result of varying salinity within lakes of the semi-arid, Mediterranean-type, climatic zone. (There are other papers by Burne on related topics that relevant to Purbeck palaeoenvironments).

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Carozzi, A. 1948. Etude Stratigraphique et Micrographique du Purbeckien du Jura Suisse. Faculte des Sciences, Universite de Geneve, 175 pp. Stratigraphic and Micrographic Study of the Purbeckian of the Swiss Jura. Thesis presented at the Faculty of Sciences at Geneva University for degree of Doctor of Science in Geology and Mineralogy. Thesis No. 1122. This work is in printed and published paperback book format. [This is a classic, early, petrographic study of the Purbeck Formation, with quantitative data. Extract (which I have translated from the French): "The Purbeckian of the Swiss Jura presents two palaeogeographic domains that are quite distinct, already in part delimited by Maillard. The most extensive is the domain of the Lower Dolomitic Beds which covers the Vaudois Jura and the southern part of the Neuchatelois Jura and the Jura Bernois Jura. From the bottom to top there are 1. The Lower Dolomitic Beds (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), and 3. Upper Brackish or Upper Marine (Upper Purbeck)...
To the north of this zone in the heart of the Neuchatelois Jura is the domain of the marls with gypsum. The type succession is from bottom to top: 1. Marls with Gypsum (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), Upper Brackish or Marine Beds (Upper Purbeck)."
[A variety of interesting Purbeck topics are discussed including the Black Pebbles, the multicoloured breccio-conglomerates, the source of Mg, the charophytes, ostracods, the grumeleux limestones (also common in Dorset), the dolomites (cf. the Lower Purbeck dolomitic marls of Dorset), pelletoidal limestones ("pseudo-ooliths"), microbreccias, cargneules, celestite, gastropods, Dasycladiaceans (not present in Dorset), cylces of sedimentation, and faecal pellets. It has many graphic logs and maps and a good bibliography of the older Purbeck literature, much of which is not listed here. An important aspect is that Carozzi related Purbeck facies to palaeotectonics, with the dolomite facies of the Lower Purbeck girdling the gypsum facies which mostly occurs on the structural highs. The Dorset Purbeck is also, of course, affected by palaeotectonics - the well-known, Late Kimmerian. However, thickness variations are rather most noticeable in Dorset than the facies variations. Carozzi does not discuss the Dorset succession, but his work is useful for comparative purposes. Carozzi's thesis is an old classic and recommended reading for Dorset Purbeck enthusiasts.]

Clements, R.G. 1993. Type-section of the Purbeck Limestone Group, Durlston Bay, Swanage, Dorset. Proceedings Dorset Natural History and Archaeological Society, 114 for 1992, 181-206. (The classic section log widely used as a reference for research on the Durlston Bay type section)

Colin, J-P., Feist, M., Grambast-Fessard, N., Cherchi, A. and Schroeder, R. 1985. Charophytes and ostracods from the Berriasian (Purbeckian facies) of Cala d'Inferno (Nurra region, NW Sardinia). Bolletin della Societa Palaeontologica Italiana, 23, 345-354.

El-Shahat, A. l977. Petrography and Geochemistry of a Limestone Shale Sequence with Early and Late Lithification: the Middle Purbeck of Dorset,England. Unpublished Ph.D.Thesis , University of Southampton. 295 pp. (on the type section of Durlston Bay)

Feist, M. and Batten, D. 1990. Comparitive charophyte and palynofloral biozonation of the British Purbeck and Wealden succession of southern England. 17-18 In: Proceedings of the International Symposium of the IGCP-245, Nonmarine Cretaceous Correlations. Alma-Atma, 72 pp.

Feist, M., Lake, R.D. and Wood, C.J. 1995. Charophyte biostratigraphy of the Purbeck and Wealden of southern England. Palaeontology, 38, Part 2, 407-442. Abstract: The distribution of charophyte assemblages in the Purbeck and Wealden sequence of southern England has been established from borehole samples from the Weald and from outcrop material collected in Dorset, Wiltshire and the Isle of Wight. Of the twenty-one taxa represented, three are new: Globator rectispirale, Clypeator britannicus and Sphaerochara andersonii; three new combinations are proposed: Globator praecursor, Globator protoincrassatus and Atopochara triquetra. The Chinese Valanginian species Flabellochara xiangyunensis is recognised for the first time in Europe. In the context of the phylogeny of the Family Clavatoraceae, G. rectispirale represents the Jurassic ancestor of the Globatorlineage and a separate origin is suggested for both Flabellochara and Clypeator. The correlation established with the Tethyan realm locate the Jurassic Cretaceous boundary within the Lulworth Formation of the Purbeck Group; in this context, the whole 'Purbeck' sequence of Swindon (Wiltshire) is attributed to the Upper Tithonian. The distribution of the Clavatoraceae indirectly confirms the contemporaneity of the Boreal Galbanites kerberus and Titanites anguiformis with the Tethyan 'Durangites' ammonite zones. For the Wealden Supergroup, the charophyte data affirm the Hauterivian-Barremian boundary near the upper division of the Weald Clay and the Upper Barremian is identified at the base of the Vectis Formation of the Isle of Wight.

Feist, M. and Schudack, M. 1991. Correlation of charophyte assemblages from the non-marine Jurassic-Cretaceous transition of NW Germany. Cretaceous Research, 12, 495-510.

Forbes, E. 1851. On the succession of strata and distribution of organic remains in the Dorsetshire Purbecks. Reports of the British Association for the Advancement of Science (1850), Abstracts, pp. 79-81.

Groves, J. 1924a. Clavator Reid and Groves. Journal Botany, 62, 116-117.

Groves, J. 1924b. A sketch of the geological history of the charophyta. In: Groves, J. and Bullock-Webster, G.R. British Charophyta, vol. 2, pp 72-90. Ray Society, London.

Groves, J. 1933. Charophyta. Fossilium Catalogus, 2, Plantae, pars 19, 74 pp. Berlin.

Groves, J. and Bullock-Webster, G.R. British Charophyta, vol. 2, pp 72-90. Ray Society, London.

Harris, T.M. 1939. British Purbeck Charophyta. British Museum (Natural History). London, Printed by Order of the Trustees of the British Museum, Issued April 22nd, 1939. 83 pp + 17 plates. (by Professor Thomas Maxwell Harris, Professor of Botany in the University of Reading - Prof. Tom Harris, well-known for studies of Mid. Jurassic plants).

Platt, N.H. 1991. Lacustrine carbonates and pedogenesis: sedimentology and origin of palustrine deposits from the Early Cretaceous Rupelo Formation, W. Cameros Basin, N. Spain. Reprinted from Sedimentology, 1989, 665-684. Pages 323-342 in the present book. In: Wright, V.P. and Tucker, M.E. (1991) Calcretes. Int. Ass. Sedimentol., Reprint Series, 2, 352. Blackwell Scientific Publications. Oxford. ( Charophytes, ostracods, gastropods and rare vertebrates. Silicified evaporites found near the top of the sequence. Stable isotope analysis. del 13C for -7 to -11 and del 18 O from -3 to -7.5. Palustrine limestones formed through pedogenic modification of lake carbonate. Low gradient, low energy, unstratified lake. Berriasian. Dark intraclasts like black pebbles.)

Reid, C. and Groves, J. 1916. Preliminary report on the Purbeck Characeae. Proceedings of the Royal Society, London, B, 89, 252-256.

Strahan, A. 1898. The Geology of the Isle of Purbeck and Weymouth. Memoirs of the Geological Survey, England and Wales. 278pp.

Sylvester-Bradley, P.C. 1941. The Purbeck Beds of Swindon. Proceedings of the Geologists' Association, London, 51, 349-372. (Records of Clavator reidi, Flabellochara grovesi (Harris) ("Clavator grovesi") etc in basal Purbeck or possibly Portland equivalent beds).

Sylvester-Bradley, P.C. 1949. A section of the Purbeck Beds at Poxwell. Proceedings of the Geologists' Association, London, 60, 151-3. (Middle Purbecks with charophytes etc. Parts of this are still exposed).

West, I.M. 1961. Lower Purbeck Beds of Swindon Facies in Dorset. Nature, 190, p. 526.

Wethered, E. 1890. On the occurrence of fossil forms of the genus Chara in the Middle Purbeck Strata of Lulworth, Dorset. Proceedings of the Cotteswold Nat. Field Club, 10, 101-103.

Chert

Garden, I.R. 1991. Changes in the provenance of pebbly detritus in southern Britain and northern France associated with basin rifting. In Morton, A.C., Todd, S.P. and Haughton, P.D.W. (eds.), 1991. Developments in Sedimentary Provence Studies. Geological Society Special Publication, No. 57, 273-289.(Upper Jurassic and Lower Cretaceous pebble suites of southern Britian and Normandy are separable into six assemblages. Assemblage 1 - Carboniferous shelf chert. Assemblage 2 - Quartz with Carb. basinal chert and with some Jurassic (incl. Purbeck) chert. Sourced from Cornubia. Assemblage 3 - Carb. shelf chert with silic. volcanics. From Welsh massif. Lower Greensand pebble beds. Some Jurassic material. Assemblage 4 - Quartz with sandstone and some Carb. shelf chert. Kent. Source Anglo Brabant massif. Assemblage 5 - Quartz Carb. shelf chert. Lincolnshire. From northern Anglo-Brabant Massif. Assemblage 6 -Quartz with some Jurassic material. Normandy. From Cotentin High. Mesozoic cherts include silicified evaporites and silificied wood. Portland and Pb. cherts locally common in Wessex and Gault of Dorset and scarce in LGS of IOW. Allen (1960) reported Portland chert in Hasting Group of Weald and West and Hooper (1969) in the Pb of Dorset (+ phosphate). Some useful palaeogeographic maps.)

West,I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association., 86, 205-225.

Chert Debris From Purbecks

Kellaway, G.A., Redding, J.H., Shephard-Thorn, E.R. and Destombes, J-P. 1975. The Quaternary History of the English Channel. Philosophical Transactions of the Royal Society of London, A 279, 189-218. (Purbeck detritus in high Avon terrace. See also Reid on the same topic but with different explanation)

Cherty Freshwater Member (Cherty Freshwater Beds)

To be added to.

Cherty Freshwater Analogues

Gimenez, J. and Calvet, F. 1990. Seasonal control into ostracod-rich facies in the Lower Eocene, southeastern Pyrenees, Spain. 13th Int. Sed. Congress, Nottingham, p.190. (Authors - Department G.P.P.G., University of Barcelona, Barcelona, Spain).

Peterson, M.N.A. and Von der Borch, C.C. 1965. Chert: modern inorganic deposition in a carbonate-precipitating locality. Science, 149, 1501-1503. pH control over silicification. Good Purbeck analogue.

Platt, N.H. and Wright, V.P. 1991. Lacustrine carbonate facies models, facies distributions and hydrocarbon aspects. Pp. 57-74. in Anadon, P. Cabrera, L. and Kelts, K. 1991. Lacustrine Facies Analysis. I.A.S. Special Publication No. 13, Blackwell Scientific Publications, Oxford, £40, ISBN - 10632-03149-2. QE 471 INT.

Chironomids, Cheironomids (Including Special Purbeck Analogues)

Cornee, A., Dickman, M. and Busson, G. 1992. Laminated cyanobacterial mats in sediments of solar salt works: some sedimentological implications. Sedimentology, 39, 599-612. (Chironomid - p. 600, important - salinity controls on gastropod grazing, petees. Chironomids could tolerate up to almost 100 parts per thousand salinity. This may be evidence against the Bosence 1987 and Perry 1993 Portland freshwater tufa arguments)

Walker, I.R.; Wilson, S.E.; Smol, J.P. 1995. Chironomidae (diptera) - quantitative paleosalinity indicators for lakes of western Canada Canadian Journal of Fisheries and Aquatic Sciences. 52, 5, 950-960.

Cinder Bed (And Analogues)

Allen, P. and Wimbledon, W.A. 1991. Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas. Cretaceous Research, 12, 511-526. ( Event stratigraphy is used with caution ... Thus .. gypsum near the base of the sequence might not have been generated by a regional climatic event. Likewise transgression-regression phases do not necessarily reflect eustatic changes of sea-level. Independent tests of synchoneity needed. Cinder may be diachronous (Wimbledon & Hunt, 1983). J-K boundary at Berriasella jacobi zone ? At Durlston the Cypris Freestone palynomorphs and overlying ostracods equate with the Pseudosubplanites grandis subzone (above the jacobi zone). Thus the Cretaceous base corresponds to Purbeck base. If Berriasian base, however, drawn at Subthurmannia subalpina subzone then the J-K boundary will be at or a little below the quasi marine Cinder Bed. Cinder Bed is followed by the early Cretaceous rise of kaolinite. )

Andrews, J. E. and Walton, W. 1990. Depositional environments within Middle Jurassic oyster-dominated lagoons: an integrated litho-, bio-and palynofacies study of the Duntulm Formation (Great Estuarine Group, Inner Hebrides). Trans. Roy. Soc. Edinburgh: Earth Sciences, 81, 1-22.

El-Shahat, A. l977. Petrography and Geochemistry of a Limestone Shale Sequence with Early and Late Lithification: the Middle Purbeck of Dorset,England. Unpublished Ph.D.Thesis , University of Southampton. 295 pp. (detailed thin-section petrography, trace element geochemistry, and clay mineralogy of the Purbeck type section of Durlston Bay)

El-Shahat, A. and West, I.M. 1982. Early and late lithification of Aragonite Bivalve Beds in the Purbeck Formation (Upper Jurassic -Lower Cretaceous of Southern England). Sedimentary Geology, 35: 15-41. (Petrography and trace-element geochemistry of the Middle Purbecks).

Grinnell, R.S. 1974. Vertical orientation of shells on some Florida oyster reefs. J. sediment. Petrol., 44, 116-122. (Analogue of Purbecks - not a Purbeck reference)

Littlewood, D.T,J. and Donovan, S.K. 1988. Variations of Recent and and fossil Crassostrea in Jamaica. Palaeontology, 31, 1013-1028.

Strahan, A. 1898. The Geology of the Isle of Purbeck and Weymouth. Memoirs of the Geological Survey, England and Wales. 278pp.

Wimbledon, W.A. and Hunt, C.O. 1983. The Portland Purbeck junction (Portlandian-Berriasian) in the Weald and correlation of latest Jurassic-early Cretaceous rocks in southern England. Geological Magazine, 120, 267-280. (Cinder might be diachronous ).

Circular Depressions

Steele-Petrovich, H.M. 1987. Sedimentary mounds and washout depressions from the middle Ordovician limestone, Ottawa Valley, Canada. Journal of Sedimentary Petrology, 58, 304-311.

Clastics

Garden, I.R. 1991. Changes in the provenance of pebbly detritus in southern Britain and northern France associated with basin rifting. In Morton, A.C., Todd, S.P. and Haughton, P.D.W. (eds.), 1991. Developments in Sedimentary Provenance Studies. Geological Society Special Publication, No. 57, 273-289.

Clays

Allen, P., Parker, A., and Wimbledon, W.A. 1992. research in progress. Detrital petrography and clay-mineralogy of the Purbeck-Wealden sediments in the Wessex Basin. Supported by the Nature Conservancy Council. In Postgraduate Research Institute for Sedimentology, University of Reading, Annual Report 1991-1992, p. 16. (Detailed logging and sampling of the Purbeck sediments in Dorset (Mupe Bay and Durlston Bay) have been completed and a start made on the Wealden. Trench digging on the Mupe Bay cliffs was aided by Open University students. Further progress towards palaeoclimatological and syntectonic obtjectives will depend substantially on changes in detrital compositions and the mixed-layer clay minerals, and on stable-isotope work. Support: Nature Conservancy Council. )

Allen, P. and Wimbledon, W.A. 1991. Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas. Cretaceous Research, 12, 511-526. Keywords - Germany, dating, France, clays, kaolinite, Platylenticeras, Jurassic-Cretaceous boundary, magnetostratigraphy, sequence stratigraphy, ostracods, palynomorphs, Classopolis decline, Cypridea posticalis, quasi marine Cinder Bed is followed by early Cretaceous rise of kaolinite. Rise in kaolinite above the Serpulite Netherlands basaltic breccia - Pb?

Deconinck, J.F. 1987. Minéraux argileux des faciès purbeckiens: Jura suisse et français, Dorset (Angleterre) et Boulonnais (France). Clay minerals of Purbeckian facies: Swiss and French Jura, Dorset (England) and Boulonnais (France). Ann. Soc. Géol. Nord., 106, 285-297. (Palygorskite in Lower Purbeck, Dorset, kaolinite in Boulonnais and in Dorset Middle Purbeck).

Deconinck, J.F. and Strasser, A. 1987. Sedimentology, clay mineralogy and depositional environment of Purbeckian green marls (Swiss and French Jura). Eclogae geol. Helv., 80, 753-772. Abstract: Purbeckian green marls in the Swiss and French Jura usually occur at the top of small-scale shallowing upward sequences which commonly end with evidence of subaerial exposure. Clay mineralogical assemblages are mainly composed of illite and detrital Al-Fe smectite in the northwestern parts of the study area, and almost entirely of illite in the southeast. This geographical distribution originates (a) from detrital input caused by the erosion of smectite-rich soils which developed in downstream continental areas under hot and seasonally humid climates, (b) from transitions of Al-Fe smectite to Fe-illite determined by cyclic wetting by marine waters and drying. These results are in agreement with mixed marine and freshwater fossils found in the green marls, and with their sedimentological context. (Palygorskite is also present)

Deconinck, J.F., Strasser, A. and Debrabant, P. 1988. Formation of illitic minerals at surface temperatures in Purbeckian sediments (Lower Berriasian, Swiss and French Jura). Clay Minerals, 23. 91-103. Abstract: The clay-mineralogical assemblage of Purbeckian carbonate sediments of the Swiss and French Jura Mountains are often composed of illite and interstratified illite-smectite. These illitic minerals occur mainly in thin layers of green marls which show evidence of subaerial exposure and mark the top of the shallowing upward sequences. X-ray diffraction, chemical and thermal analyses coupled with transmission electron microscopy suggest that the Purbeckian illitic minerals replaced smectite in intermediate continental-marine environments. The transition from smectite to illite and interstratified illite-smectite probably resulted from repeated cycles of wetting by marine waters and subsequent drying in hypersaline environments, under a hot Purbeckian climate.

El-Shahat, A. l977. Petrography and Geochemistry of a Limestone Shale Sequence with Early and Late Lithification: the Middle Purbeck of Dorset,England. Unpublished Ph.D.Thesis , University of Southampton. 295 pp. (Includes clay mineralogy of the middle part of the Purbeck type section of Durlston Bay and first showed the kaolinite increase above the Cinder Bed)

Hallam, A., Grose, J.A. and Ruffell, A.H. 1991. Palaeoclimatic significance of changes in clay mineralogy across the Jurassic-Cretaceous boundary in England and France. Palaeogeography, Palaeoclimatology,Palaeoecology, 81, 173-187. (Palygorskite recorded in lower Purbeck. Arid or semi-arid origin. South of France, Vocontian Basin, Speeton Clay. Speculations on the cause of end-Jurassic aridity. Uplift of Cimmerides in southern Eurasia may have isolated Europe from the near body of ocean water to the east (more important climatically than water to the west). Another possibility is that end-Jurassic uplift of the Arabian Shield, well attested by stratigraphic datsa from the Middle East had an orographic effect on regions further west. )

Hartland-Swann, J.K. 1989. An investigation of the Marly Freshwater Member and the Cherty Freshwater Member of the Purbeck Formation of Durlston Bay, Dorset, England. Unpublished undergraduate project. April 1989. 69p.

Hurst, A. 1985. The implications of clay mineralogy to palaeoclimate during the Jurassic in N.E. Scotland. Scottish Journal of Geology, 2, 143-160. (Relevant to Purbeck)

Persoz, F. and Remane, J. 1976. Mineralogie et geochemie des formations a la limite Jurassique-Cretace dans le Jura et le Bassin vocontien. Eclogae Geol. Helv., 69/1, 1-38. (Palygorskite found in Purbeck facies).

Ruffell, A. 1990. The Tithonian and Barremian arid phases in Europe and their effect on sequence stratigraphy. 13th International Sedimentological Congrress, Nottingham. (Arid phase in top Wessex Fm., Wealden, I.O.W. with palygorskite).

Sladen, P.S. 1983. Trends in Early Cretaceous clay mineralogy in N.W. Europe. Zitteliana, 10, 349-357.

Sladen, P.S. 1984. Source-area environments of late Jurassic and Early Cretaceous sediments in southeast England. Proceeding of the Geologists' Association., 95, 149-163.

Clays - Analogues

Wright, V.P. and Sadler, A. 1994. A hydrogeological model for the early diagenesis of Late Triassic alluvial sediments. Journal of the Geological Society, London, 151, 897-900. See also Discussion of this - Leslie, A.B. and Tucker, M.E. 1995. Discussion on a hydrogeological model for the early diagenesis of Late Triassic alluvial sediments. Journal of the Geological Society, London, 152, 732-734. (Discussion of marine versus continental waters - very relevant to the Purbeck. Clay diagenesis etc. See also Leslie and Tucker papers - Sedimentology 1992 and JGS 1993).

Correlation - Purbeck - General

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Abbink, O.A., Callomon, J.H., Riding, J.B., Williams, P.D.B. and Wolfard, A. 2001. Biostratigraphy of Jurassic-Cretaceous boundary strata in the Terschelling Basin, The Netherlands. Proceedings of the Yorkshire Geological Society, 53, 275-302, Abstract: The Jurassic-Cretaceous boundary beds in the Scruff Greensand Formation from Dutch sector North Sea wells L06-2 (between 2245.36m and 2262.76m) and L06-3 (between 2028.90m and 2037.80m) have yielded both ammonite faunas and abundant marine and terrestrial palynomorphs. Ammonite endemism in Europe was intense at the Jurassic-Cretaceous boundary. This means that pan-European correlations of Jurassic-Cretaceous boundary beds based on macrofossils are problematical. The ammonite faunas of wells L06-2 and L06-3 provide the most extensive and complete marine macrofossil record so far across the Volgian-Ryazanian (Jurassic-Cretaceous) boundary in the Spilsby Province and the North Sea Basin. The Primitivus, Preplicomphalus, Lamplughi, Runctoni and Kochi Zones have been identified. In both wells, the occurrences of the dinoflagellate cyst Gochteodinia virgula mean that the successions are no older than latest mid-Volgian. The dinoflagellate cyst associations of L06-2 are indicative of the late Volgian/early Ryazanian. The range tops of Gochteodinia virgula and Amphorula expirata are revised as a result of correlations with the ammonite zonation. Dinoflagellate cyst floras in L06-3 are indicative of the latest Volgian-?earliest Ryazanian. In particular. the co-occurrence of Batioladinium? gochtii and Gochteodinia virgula at 2030.60m in well L06-3 together with ammonite data, indicates that this horizon is of latest Volgian (Lamplughi Zone) age. Both wells contain reworked palynomorphs, including recycled older Late Jurassic dinoflagellate cysts. In addition, the palynological assemblages yield relatively diverse sporomorph associations. The sporomorph succession of both wells is used to establish an ammonite-calibrated sporomorph chronostratigraphy. Comparison with other studies suggests that the Jurassic/Cretaceous boundary occurs within the Cherty 'Freshwater' Beds of the Purbeck Limestone Group in Dorset, southern England, and within the Serpulite Member of Germany.
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Allen, P. 1955. Age of the Wealden in N.W. Europe. Geological Magazine, 92, 265-281. Attempts to discredit Wolburg's (1949, 1950) view that the Wealden of the Weald is entirely Valanginian.. Refers to the Swindon Wealden.

Allen, P. and Wimbledon, W.A. 1991. Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas. Cretaceous Research, 12, 511-526. The Jurassic/Cretaceous boundary is at the base of the Purbecks using palynomorphs. See Hunt, however.

Allen, P. and Wimbledon, W.A. 1991. Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas. Cretaceous Research, 12, 511-526. (Purbeck is Berriasian (Cretaceous) Abstract - (notes from it only ) - Correlation within and between the onshore basins is reviewed and revised. English Wealden and Purbeck stratotypes in separate subbasins, overlap in time and not fully correlated. North of mid-European source massifs (presumably this means London North Sea uplands - Ardennes etc) Pb-Wealden facies are wholly Purbeck in age. South of the massifs the Paris Basin succession resembles that in England and is substantially Berriasian to Barremian. Boulonnais succession largely Portlandian with some upper Wealden further east. Event stratigraphy is used with caution .... Thus .. gypsum near the base of the sequence might not have been generated by a regional climatic event. Likewise transgression-regression phases do not necessarily reflect eustatic changes of sea-level. Independent tests of synchoneity needed. Cinder may be diachronous (Wimbledon & Hunt, 1983). J-K boundary at Berriasella jacobi zone ? At Durlston the Cypris Freestone palynomorphs and overlying ostracods equate with the Pseudosubplanites grandis subzone (above the jacobi zone). Thus the Cretaceous base corresponds to Purbeck base. If Berriasian base, however, drawn at Subthurmannia subalpina subzone then the J-K boundary will be at or a little below the quasi marine Cinder Bed. Pb spans Berriasian but how far it extends up into the Valanginian is unknown. Bundle of horizons - Classopolis decline, Cypridea posticalis, quasi marine Cinder Bed is followed by early Cretaceous rise of kaolinite. Hiatus oily boulder sandstone of Wealden. Pine raft = Coarse Quartz Grit? Broadoak Member contains Berriasian charophytes. Wealden - Harding references. Wealden - lacustrine, lagoonal, bay in Weald. Arenaceous fluvial in Wessex. German invertebrates - Swindon. Rise in kaolinite above the Serpulite Netherlands basaltic breccia - Pb? Purbeck Iguanodon hoggi different from Wealden of Belgium etc. Some gypsum in Lower Purbeck. Dating - Purbeck base at 141 My. Some magnetostratigraphy - reversals CM 18 - CM in Pb. )

Anderson, F.W. 1973. The Jurassic-Cretaceous transition: The non-marine ostracod faunas. In: R.Casey & P.F.Rawson (Eds.) The Boreal Lower Cretaceous. Seel House Press, Liverpool, Special Issue Geological Journal, 5, 101-110.

Casey, R. 1963. The dawn of the Cretaceous Period in Britain. Bull. South-East Union Scientific Soc. 117, 1-15. (originally a key paper in linking the Cinder Bed with the basal Cretaceous transgression of the Boreal Realm)

Casey, R. 1967. The position of the Middle Volgian in the English Jurassic. Proceedings of the Geological Society, London, 1640, 128-133.

Casey, R. 1973. The ammonite succession at the Jurassic-Cretaceous boundary in eastern England. In: R. Casey and P.F. Rawson (Eds.) The Boreal Lower Cretaceous. Seel House Press, Liverpool, Special Issue Geological Journal., 5, 193-266.

Casey, R. and Bristow, C.R. 1964. Notes on the ferruginous strata in Buckinghamshire and Wiltshire. Geol.ogical Magasine, 101, 116-128.

Casey, R. and Gallois, R.W. 1973. The Sandringham Sands of Norfolk. Proceedings of the Yorkshire Geological Society, 40, 1-22.

Cope, J. C.W., Duff, K.L., Parsons, C.F., Torrens, H.S., Wimbledon, W.A. and Wright, J. K. (1980). A correlation of Jurassic rocks in the British Isles. Part two: Middle and Upper Jurassic. Geological Society of London, Special Report, 15: 1-109. (note that the position of the J-K boundary has since changed)

Feist, M., Lake, R.D. and Wood, C.J. 1995. Charophyte biostratigraphy of the Purbeck and Wealden of southern England. Palaeontology, 38, Part 2, 407-442. Abstract: The distribution of charophyte assemblages in the Purbeck and Wealden sequence of southern England has been established from borehole samples from the Weald and from outcrop material collected in Dorset, Wiltshire and the Isle of Wight. Of the twenty-one taxa represented, three are new: Globator rectispirale, Clypeator britannicus and Sphaerochara andersonii; three new combinations are proposed: Globator praecursor, Globator protoincrassatus and Atopochara triquetra. The Chinese Valanginian species Flabellochara xiangyunensis is recognised for the first time in Europe. In the context of the phylogeny of the Family Clavatoraceae, G. rectispirale represents the Jurassic ancestor of the Globatorlineage and a separate origin is suggested for both Flabellochara and Clypeator. The correlation established with the Tethyan realm locate the Jurassic Cretaceous boundary within the Lulworth Formation of the Purbeck Group; in this context, the whole 'Purbeck' sequence of Swindon (Wiltshire) is attributed to the Upper Tithonian. The distribution of the Clavatoraceae indirectly confirms the contemporaneity of the Boreal Galbanites kerberus and Titanites anguiformis with the Tethyan 'Durangites' ammonite zones. For the Wealden Supergroup, the charophyte data affirm the Hauterivian-Barremian boundary near the upper division of the Weald Clay and the Upper Barremian is identified at the base of the Vectis Formation of the Isle of Wight.
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Hoedemaeker, P.J. 1987. Correlation possibilities around the Jurassic/Cretaceous boundary. Scripta Geol., 84, 1-64.

Hoedemaeker, P.J.1991. Tethyan-boreal correlations and the Jurassic-Cretaceous boundary. Newsletters on Stratigraphy, 25: (1) 37-60. Abstract: The author (1987) was able to determine three inter-realmally correlatable horizons, which are relevant with respect to the stratigraphic position of the Jurassic-Cretaceous boundary (see Fig. 2): 1. The rock interval in the upper part of the Buchia 'elderensis' Subzone in California which yielded the ammonite genus Kossmatia. This interval correlates with (a) a part of the Tethyan 'Durangites' Zone and with (b) a part of the boreal Epivirgatites variabilis Zone. 2. The concurrent range of the ammonite subgenera Spiticeras (Proniceras) and Spiticeras (Spiticeras) in the upper part of the Buchia fischeriana Zone and the lower part of the Buchia aff. okensis Zone in California provides a correlation of this interval with (a) the upper part of the Tethyan Berriasella jacobi Subzone and with (b) the upper part of the boreal Craspedites okensis Zone and the Taimyroceras taimyrense Zone. 3. The ammonites found in the upper part of the Buchia okensis Zone in British Columbia ('Argentiniceras' ex gr. noduliferum/bituberculatum) and in the lower part of the Buchia uncitoides Zone in California and British Columbia (Neocosmoceras) allow of a correlation of that stratigraphic interval with (a) at least a part of the Tethyan Berriasella paramimouna Subzone and with (b) the lower part of the upper division of the boreal Hectoroceras kochi Zone. The Jurassic-Cretaceous boundary voted for in the Lyon colloquium (1973), viz. at the base of the Berriasella jacobi Subzone (boundary A), is situated between horizons 1 and 2, and correlates approximately with the base of the Siberian Craspedites okensis Zone. The Jurassic-Cretaceous boundary advocated by the author (1981, 1982, 1987), viz. at the top of the Pseudosubplanites grandis Subzone (boundary B), is situated between horizons 2 and 3, and interpreted to correlate with the top of the Chetaites chetae Zone. All four boundaries are characterized by rapid and important change-overs in the composition of the ammonite faunas in the Tethyan as well as in the Boreal Realm. The change-overs were ascribed to eustatic sea level lows. The Tethyan faunal turn-overs can therefore be considered contemporaneous with the boreal ones. Boundary A is chronostratigraphically closest to the top of the Jurassic as it was erroneously conceived by D'Orbigny (1850). Boundary B is however closest to the base of the Cretaceous as it became accepted after the introduction of the Neocomain as the lowest 'stage' of the Cretaceous (Thurmann, 1836) and therefore also closest to the top of the Tithonian as originally defined by Oppel (1865) (often erroneously quoted as if he had included the Berriasian in the Tithonian). It corresponds with the base of the Berriasian as it was originally conceived by Coquand (1869 to 1875). Since boundary B is also chronostratigraphically closest to the top of the Volgian in Siberia and to the top of the Portlandian as recently conceived in England, this boundary had best be considered the most appropriate Jurassic-Cretaceous boundary.

Hoedemaeker, P.J. 1999. A Tethyan-Boreal correlation of pre-Aptian Cretaceous strata: Correlating the uncorrelatables. Geologica Carpathica, 50, (2), 101-124, April 1999. Abstract: Because of the high provinciality of the marine biota during the pre-Aptian Cretaceous times, there is no hope of a precise correlation of Tethyan with Boreal successions by means of biostratigraphy alone. Correlations with a detail as shown in the correlation schemes presented here, can be achieved only with the combination of all available correlation tools such as biostratigraphy, magnetostratigraphy and sequence stratigraphy. Author Keywords: Tethyan-Boreal correlation, pre-Aptian Cretaceous, biostratigraphy, magnetostratigraphy, sequence stratigraphy, Spain, France, Germany, England.
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Hunt, C.O. 1987. Dinoflagellate cyst and acritarch assemblages in shallow-marine and marginal-marine carbonates: the Portland Sand, Portland Stone, and Purbeck Formations (Upper Jurassic/Lower Cretaceous) of southern England and northern France. In: Micropalaeontology of Carbonate Environments (ed. Hart, M.B.), pp. 208-225, Ellis Horwood, Chichester. Hunt placed the Jurassic/Cretaceous boundary just above the base of the "Cypris " Freestones, on the basis of palynomorphs. This is supported by Feist et al. 1995).
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Mateer, N.J. 1989. Advances in correlating non-marine Cretaceous rocks. International Geological Correlation Programme, 245.
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Ogg, J.G., Hasenyager, R.W., Wimbledon, W.A., Channel, J.E.T. and Bralower, T.J. 1991. Magnetostratigraphy of the Jurassic-Cretaceous boundary interval - Tethyan and English faunal realms. Cretaceous Research, 12, 455-482. Abstract: Geomagnetic reversals and magnetic polarity chrons provide an important chronostratigraphic tool for global correlation. An integrated Tithonian-Berriasian biostratigraphic and magnetic polarity time scale for the Tethyan faunal realm for the Tithonian and Berriasian stage is compiled from 17 independent biomagnetostratigraphic sections. This time scale incorporates zones and first/last appearance datums form ammonites, calpionellids, calcareous nannofossils and dinoflagellates. The database provides an estimate of the range of observed appearance datums or zonal boundaries relative to polarity chrons; such apparent "diachoniety" probably results from a combination of preservation of species and paleontological methodology, rather than migration. The lithologic transition from "Rosso Ammonitico" red marly limestone to "Maiolica" white limestone occurs at different times during the Tithonian among the various sections, ranging from polarity zone M22n (mid-Early Tithonian) in some Spanish "slope" and Italian basinal-facies sections, ranging from polarity zone M19n (mid-Late Tithonian) in the central Atlantic and some plateau-facies Italian sections. This widespread lithological change is, therefore, probably a result of shifting local patterns of fertility overprinted on the main regional trend. Magnetostratigraphy from the Purbeck Limestone Formation in the English Boreal faunal realm was obtained from the "classic" section at Durlston Bay in Dorset. The Dorset section displays predominantly normal polarity with a minimum of three reversed-polarity zones, but distortion of the magnetic polarity record by variable rates of sedimentation in this marginal clastic environment coupled with lack of independent correlation methods currently precludes a unique correlation to the Tithonian-Berriasian magnetic polarity time scale. The Tithonian-Berriasian magnetic polarity time scale may eventually provide a global chronostratigraphic definition of the Jurassic-Cretaceous boundary. End of Abstract....[Notes re Purbeck of Dorset: Durlston Bay section. Predominantly normal polarity with three reversed polarity zones but distortion of pattern by variable sedimentation rates coupled with lack of independent methods precludes unique correlation to Tithonian-Berriasian magnetic polarity time scale. M 18r to M 15 r. Keywords: ammonites, Atlantic, Bay, Berriasian, Boreal, calpionellids, chron, correlation, Cretaceous, dinoflagellates, Durlston, geomagnetic, geomagnetism, magnetic, magnetostratigraphy, M-sequence, nannofossils, palaeomagnetism, paleomagnetism, polarity, reversal, Purbeck, stratigraphy, Tithonian, zone]
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Rawson, P.F., Curry, D., Dilley, F.C., Hancock, J.M., Kennedy, W.J., Neale, J.W., Wood, C.J. and Worssam, B.C. 1978. A Correlation of Cretaceous Rocks in the British Isles. Geological Society, London, Special Report 9, 70pp.
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Ruffell, A. 1991. Sea-level events during the Early Cretaceous in Western Europe. Cretaceous Research, 12, 527-551. (A Europe-wide sea-level lowstand in the latest Jurassic- earliest Cretaceosus has been interpreted by Hallam (1977, 1988), Rawson and Riley (1982) and Haq et al. (1988) as a second order sea level fall.)

Taylor, P.D. (Ed.) 1996. Field Geology of the British Jurassic. 286p. The Geological Society of London. ISBN - 1-897799-41-1 Softback. List price £65. Members of Geol. Soc. £29. (Excursion guides relating to the 1993 W.J. Arkell Symposium held in London. Collection of eight articles covering these areas. 1. Cope introduces British Jurassic and points out importance re Tethyan-Boreal correlations. Clear cut base within Blue Lias but poorly defined boundary at top in Purbeck. 75 ammonite zones. Bononian Stage (up.Kim.) reappears. Excursions - Warrington and Ivimey Cook, Triassic and Jurassic of Somerset and South Wales, Mudge, Middle Jur of Cotswolds, Callomon and Cope, 1996, Jurassic of Dorset coast ; H Hesselbo and Jenkins, Hetangian to Bajocian, Coe, Oxfordian, Rawson and Wright,Jurassic of Cleveland Basin, Morton and Hudson, Jurassic of Raasay and Skye. Much detail. Errors in early version have been corrected in the econd edition. )

Westhead, R.K. 1992. Geology of the Dorchester (South) District (Dorset). 1:10,000 Sheet SY NE. British Geological Survey Technical Report WA/93/22. (Also includes part of 1:50,000 Sheet 328 Dorchester, 327 Bridport and 341/342 Weymouth). (Mapping by Westhead. Logging of Purbeck Group pits was undertaken by A.E. Mather (Plymouth University), who also provided sedimentological information. Purbeck succession divided into (from base) Windsbatch Limestone Mb, Bincombe Mb, Ridgeway Mb, Bayard Hill Limestone Mb and at top Friar Waddon Member. Unfortunately this is simplistic with regard to the Purbeck Formation and units are simply listed as "micrite" and shown without detailed description except where Ensom's work is used. The new terminology is a simplification and I do not think that it is going to be useful for researchers working on the Purbecks in detail. Of course, it might well have been useful to the authors for purely mapping purposes, so no doubt they have grounds for wishing to set it up.

Westhead, R.K. and Mather, A.E. 1996. An updated lithostratigraphy for the Purbeck Limestone Group in the Dorset type-area. Proceedings of the Geologists' Association., 107, 117-128. (See comments above with regard to Westhead, 1992 )

Wiedmann, J. 1987. (ed.). Cretaceous of the Western Tethys. Proceedings of the 3rd International. Cretaceous Symposium, Tubingen 1987. E. Schweizerbart'sche Verlagsbuchhandlung (Nagele u. Obermiller) Stuttgart. 1005 p. 372 figs. DM 228, US$ 141, ISBN 3-510-65140-5.

Wiedmann, J. 1979. Aspekte der Kreide Europas/ Aspects of the Cretaceous in Europe. Beitrage zum 1. Symposium Deutsche Kreide -Bindeglied zwischen Boreal und Tethys - Munster 1. Westfalen, April 1978. ISBN 3-510-56004-3.E. Schweizerbart'sche Verlagsbuchhandlung (Nagele u. Obermiller) Stuttgart. (The Cretaceous Subcommission of the Stratigraphic Commission of the Federal German Republic organised a symposium in April 1978 entitles " German Cretaceous -link between Boreal and Tethys". Here the current state of knowledge was critically analyzed and investigations were focussed on relations between "Boreal" and Tethyan Cretaceous development in order to achieve closer correlation weith the primarily Mediterranean Standard Cretaceous zonation. It became clear that a satisfactory answer to questions on Cretaceous palaeogeography the sea routes and accompanying faunal exchanges, can only be achieved through extensive international cooperation.)

Worssam, B.C. and Ivimey-Cook, H.C. 1984. Comments on the paper "The Portland-Purbeck junction (Portlandian-Berriasian) in the Weald, and the correlation of latest Jurassic-early Cretaceous rocks in southern England" by W.A. Wimbledon and C.O. Hunt. Geological Magazine, 121, 651-652.

Taxonomy and biostratigraphy of schizaealean spores from the Jurassic-Cretaceous boundary beds of the Aklavik Range, District of Mackenzie. Palaeontographica Canadiana no. 4. Extract: Contents: Abstract. Résumé. Introduction and Acknowledgements. Geological Setting. Chronostratigraphic Terminology and Definitions. Tectono-stratigraphic Setting. Lithostratigraphic Units. General Remarks. Husky Formation. Martin Creek Formation. McGuire Formation. Fault Creek Formation. Lower Canyon Formation. Material General Botanical and Palynological Considerations. Classification and Nomenclature of Fossil Dispersed Spores. Botanical Affinity. Terminology. Systematic Paleontology. Dispersed ?Anemiaceous Miospores. Genus Contignisporites. Contignisporites sp. cf. C. glebulentus. Genus Crassitudisporites Crassitudisporites problematicus. Genus Cicatricosisporites. etc. etc. Part of Web Site - Publications of the Geological Association of Canada including Books, Journals, Special Papers, etc. Extract: Complete list of publications, journals, Geolog, special papers, Geoscience Canada reprint series, Nuna, Geotext, special interest, short course notes, division publications: volcanology, mineral deposits, paleontology, section publications, Palaeontographica Canadiana, new publication initiatives, GAC anniversary specials.

Crocodiles

Go to Purbeck Crocodiles

Crustaceans

Ensom, P.C. 1985. A barnacle from the Cinder Member, Purbeck Limestone Formation, Worbarrow Tout, Dorset. Proceedings of Dorset Natural History and Archaeological Society, 106, 167-168.

Cycles, Cyclicity, Cyclostratigraphy (Faunicycles, Milankovitch Etc)
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Anderson, E.J. 1999. The cyclic structure of the 'Purbeckian'at the classic Sierra del Pozo section of the Prebetic (Berriasian) southern Spain. Abstracts, Geological Society of America, Annual Meeting, Denver (November) , p. 424.

Anderson, E.J. 2000. Criteria for recognising an orbitally forced cyclic heirarchy: the 'Purbeckian' at the classic Sierra del Pozzo section (Berriasian) southern Spain. Sediment 2000, Abstracts, June, p. 20, Leoben, Austria.

Anderson, E.J. 2001a. The cyclic structure of the Purbeck Group, Lower Cretaceous, Dorset, England. Abstracts, Geological Society of America, N.E. Section Meeting, Burlington, Vermont,March, p. 67.

Anderson, E.J. 2001b. Assymmetrical facies patterns in orbitally forced 3rd, 4th, 5th and 6th order sequences: The Purbeckian of Dorset. Abstracts, SEPM Multidisciplinary Approach to Cyclostratigraphy, Workshop, Sorrento, May, pp. 12-13.

Anderson, E.J. 2001c. Integration of bed descriptions, molluscan depth zones and faunicycles with an orbitally forced four-tiered hierarchy of lithic allocycles: In the Lower Cretaceous, Purbeckian of Dorset, England. Abstracts, 21st IAS-Meeting, Davos, September, p. 71.

Anderson, E.J. and Goodwin, P.W. 1990. The significance of metre-scale allocycles in the quest for the fundamental stratigraphic unit. Journal of the Geological Society, London, 147, 507-518. [This theory may be the basis of some later studies of Purbeck "cycles" by Anderson, listed here. The present writer believes, however, that the interplay of Late Kimmerian movement, variation from basin to shelf, the occurrence of subaerially exposed intervals of unknown length, the rarity of truely marine beds, the progressive palaeoclimatic changes and particularly the lack of appropriate absolute dates makes this theory unsuitable for interpretation of the highly variable and lagoonal, Dorset Purbecks. The discussion on limitations on Walther's Law is probably of relevence, though.]

Anderson, E.J., Perry, L.L. and Stynchula, J.A. 2001. Lateral continuity and discontinuity of 100 ka eccentricity sequences within an orbitally forced cyclic hierarchy: The Purbeck Group, Lower Cretaceous, Dorset, England. Abstracts of the Geological Society of America, Annual Meeting, Boston, p. 323.

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Anderson, F.W. 1932. Phasal deposition in the Middle Purbeck Beds of Dorset. Report of the British Association for the Advancement of Science, London, for 1931. (published 1932?) pp. 379-380. (Extract: Three phases may be recognised in the lower half of the Middle Purbeck . The beginning of each phase is marked by fresh-water deposits, grey marls and shell limestones containing Paludina, Unio, Cyrena and freshwater Ostracods. Throughout the phase there was a gradual shallowing of the water an increase in salinity; towards the end deposition decreased and cherty limestones (shell breccias) are the typical deposit. Limnaea, Planorbis and Corbula are characteristic of this brackish water stage. .. [ostracod data follows]..)

Anderson, F.W. 1973. The Jurassic-Cretaceous transition: The non-marine ostracod faunas. In: R.Casey & P.F.Rawson (Eds.) The Boreal Lower Cretaceous. Seel House Press, Liverpool, Spec. Issue, Geol. Journal, 5, 101-110.

Anderson, F.W. l985. Ostracod faunas in the Purbeck and Wealden of England. Journal of Micropaleontology, 4, pp.l-68. Abstract: The occurrence and abundance of ostracods found in 98 subdivisions (Faunicycles) of late Jurassic to early Cretaceous age in the English Purbeck and Wealden are summarised. Most of the taxa found are illustrated from holotype or other material and details of their ranges and abundance given in relation to each faunicycle. The characters of the ostracod assemblages and zones are decribed. Three new species (Cypriea brendae, C. hispida and Eoparacypris edmundsi) ; also two new subspecies (Cypridea setina pelota and C. tuberculata dorsiclavata) are described and figured. A lectotype for Palaeocytheridea pellucida is selected and figured.

Anderson, F.W. and Bazley, R., 1971. The Purbeck Beds of the Weald (England). Bulletin of the Geological Survey of Great Britain, No. 34. Institute of Geological Sciences, N.E.R.C. Her Majesty's Stationery Office, London. 174 pp. (p. 24 - " Above the Cinder Beds horizon there is a well-developed sequence of sedimentary rhythms, each generally starting with a shelly limestone and grading up through shales to current-bedded sandstones and possibly a "soil" above..." p. 28 et seq. "Faunicycles ..... there is a constant alternation between two types of faunal assemblage, and furthermore these cycles, consisting of an S-phase below and and C-phase above, appear to be traceable thoughtout the entire area of sedimentation...")

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Carozzi, A. 1948. Etude Stratigraphique et Micrographique du Purbeckien du Jura Suisse. Faculte des Sciences, Universite de Geneve, 175 pp. Stratigraphic and Micrographic Study of the Purbeckian of the Swiss Jura. Thesis presented at the Faculty of Sciences at Geneva University for degree of Doctor of Science in Geology and Mineralogy. Thesis No. 1122. This work is in printed and published paperback book format. [This is a classic, early, petrographic study of the Purbeck Formation, with quantitative data. Extract (which I have translated from the French): "The Purbeckian of the Swiss Jura presents two palaeogeographic domains that are quite distinct, already in part delimited by Maillard. The most extensive is the domain of the Lower Dolomitic Beds which covers the Vaudois Jura and the southern part of the Neuchatelois Jura and the Jura Bernois Jura. From the bottom to top there are 1. The Lower Dolomitic Beds (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), and 3. Upper Brackish or Upper Marine (Upper Purbeck)...
To the north of this zone in the heart of the Neuchatelois Jura is the domain of the marls with gypsum. The type succession is from bottom to top: 1. Marls with Gypsum (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), Upper Brackish or Marine Beds (Upper Purbeck)."
[A variety of interesting Purbeck topics are discussed including the Black Pebbles, the multicoloured breccio-conglomerates, the source of Mg, the charophytes, ostracods, the grumeleux limestones (also common in Dorset), the dolomites (cf. the Lower Purbeck dolomitic marls of Dorset), pelletoidal limestones ("pseudo-ooliths"), microbreccias, cargneules, celestite, gastropods, Dasycladiaceans (not present in Dorset), cylces of sedimentation, and faecal pellets. It has many graphic logs and maps and a good bibliography of the older Purbeck literature, much of which is not listed here. An important aspect is that Carozzi related Purbeck facies to palaeotectonics, with the dolomite facies of the Lower Purbeck girdling the gypsum facies which mostly occurs on the structural highs. The Dorset Purbeck is also, of course, affected by palaeotectonics - the well-known, Late Kimmerian. However, thickness variations are rather most noticeable in Dorset than the facies variations. Carozzi does not discuss the Dorset succession, but his work is useful for comparative purposes. Carozzi's thesis is an old classic and recommended reading for Dorset Purbeck enthusiasts.]

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Decisneros, C.J. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, 513-537. Abstract: Peritidal carbonate rocks (Purbeck facies) of the uppermost Portlandian to Berriasian in the type section of the Sierra del Pozo Formation in the Prebetic Zone, southern Spain, are divisible into 141 shallowing upward cycles averaging 2 m in thickness. The subtidal facies in these cycles consist of micritic or marly limestones with dasycladacean algae and lituolids; the intertidal facies are micritic limestones containing birdseyes and miliolids; the supratidal facies comprise laminated algal limestones, the tops of which display desiccation cracks and rhizocretions, or more locally palaeosols, calcretes, or palaeokarst surfaces. A statistical study, using power spectra of the Fast Fourier Transform, demonstrates that the periodicity of these cycles is in the Milankovitch frequency band. Most sedimentary cycles correspond to the obliquity cycles; eccentricity and precession cycles have also been recognized. Using a Fischer plot, third-order tectono-eustatic cycles are recognized, which can be correlated with the eustatic curve of the Exxon chart. The shallowing upward sequences are characterized by a distinctive pattern of geochemical parameters. Carbon and oxygen isotopic (deltaC-13 and deltaO-18) variations, calcium and magnesium carbonate contents and the abundance of organic matter and trace elements (Mn and Sr) all have predictable patterns of distribution within the sequences. The Sr content of the subtidal facies is relatively high whereas the deltaC-13 and deltaO-18 ratios are quite low; in the intertidal facies the Sr and Mn levels fall concomitantly with a rise in deltaC-13 and deltaO-18. The highest deltaC-13 and deltaO-18 values occur in the lower part of the supratidal facies, whereas in the upper part of delta values and Sr contents drop sharply. Cyclic variations in evaporation and in meteoric water influence, determined from oxygen isotopic composition, reveal that the cyclicity of the beds containing the most limestones (supratidal) and those with the most marls (subtidal) is related to climatic changes. The coldest periods are those represented by supratidal deposits, when the sea level was at its lowest. During the warmest periods, when the overall sea level was higher, subtidal deposits accumulated in the region. A genetic model is proposed, according to which the asymmetrical sedimentary cycles occur in response to glacio-eustatic changes with a periodicity similar to that of Plio-Pleistocene sea-level variations, but with a much lower range due to the smaller extent of polar ice caps during the Early Cretaceous. The glacio-eustatic changes involved a rapid sea-level rise and a slow sea-level fall. [Comment from the present writer - It is interesting to note that the well-known Fossil Forest of the Purbecks of Dorset, UK shows evidence of rapid flooding (West, 1975)]

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Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. [Notes: Milankovitch cycles found by Fast Fourier Transform. Cycles are mainly about 40,000 year Milankovitch obliquity cycles. Role of glacio-eustasy - see also Frakes and Francis 1988, Nature. Cyclic carbonate deposition. Sierra del Pozo region, southeast Spain, near the coast, north-east of Granada. Black pebbles. Evaporites. Birdseyes. Del 13C and del 18 O isotope data. Sr ppm. Sr high in subtidal facies. Sedimentation rate 12-15 cm per 1000 yrs (ie. about 0.13 mm per annum).]

Joachimski, M. 1990. Depositional environment and shallowing upward cycles in Purbeckian carbonates: evidence from stable isotopes. 13th International Sedimentological Congress, Nottingham, Abstracts. 253-4.

Melmyk, D.H. 1990. Cyclicity in filtered wireline logs, Kimmeridge through Portlandian stages, Wessex Basin U.K. 13th International Sedimentological Congress, Nottingham, Abstracts. p354. (cycles and hiatuses - Kimmeridge - Purbeck - uranium content).
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Strasser, A. 1988. Shallowing-upward sequences in Purbeckian peritidal carbonates (lowermost Cretaceous, Swiss and French Jura Mountains). Sedimentology, 35, 369-383.
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West, I.M. 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium - Sedimentation Jurassique W. Europeen. A.S.F. Publication Speciale, No.1, March, 1979, 407-416. [Purbeck diagenesis and also cycles in the Purbeck Caps, Dorset.]

Desiccation Cracks

Desiccation cracks are very common at various horizons within the Purbeck Formation, the lower part of which is of semi-arid origin. The cracks are in some cases associated with dinosaur footprints. Their abundance is a result of the Purbeck Formation having been deposited at about mean sea-level. The sediment surface was often exposed frequently and dried out in the summer droughts of the very seasonal Mediterranean type climate. Red oxidised conditions, like those that resulted in the Wealden Group from a water-table well below the surface, are not normally developed. Desiccation was usually temporary and truely arid desert conditions did not occur in Dorset.

Andrews, J.E. 1988. Soil-zone microfabrics in calcrete and in desiccation cracks from the Upper Jurassic Purbeck Formation of Dorset. Geological Journal, 23, 261-270. Alveolar septal structure, needle fibre, desiccation cracks, calcrete.

Detritus, Reworked

Garden, I.R. 1991. Changes in the provenance of pebbly detritus in southern Britain and northern France associated with basin rifting. In Morton, A.C., Todd, S.P. and Haughton, P.D.W. (eds.), 1991. Developments in Sedimentary Provence Studies. Geological Society Special Publication, No. 57, 273-289. . Upper Jurassic and Lower Cretaceous pebble suites of southern Britian and Normandy are separable into six assemblages. Assemblage 1 - Carboniferous shelf chert. Assemblage 2 - Quartz with Carb. basinal chert and with some Jurassic (incl. Purbeck) chert. Sourced from Cornubia. Assemblage 3 - Carb. shelf chert with silic. volcanics. From Welsh massif. Lower Greensand pebble beds. Some Jurassic material. Assemblage 4 - Quartz with sandstone and some Carb. shelf chert. Kent. Source Anglo Brabant massif. Assemblage 5 - Quartz Carb. shelf chert. Lincolnshire. From northern Anglo-Brabant Massif. Assemblage 6 -Quartz with some Jurassic material. Normandy. From Cotentin High. Mesozoic cherts include silicified evaporites and silificied wood. Portland and Pb. cherts locally common in Wessex and Gault of Dorset and scarce in LGS of IOW. Allen (1960) reported Portland chert in Hasting Group of Weald and West and Hooper (1969) in the Pb of Dorset (+ phosphate).

Diagenesis - Carbonate

(See also Evaporites - Diagenesis)

Brown, P.R. 1964. Petrography and origin of some Upper Jurassic Beds from Dorset, England. J. sediment. Petrology, 34, 254-269.

Brown, P.R. 1966. Pyritization in some molluscan shells. Journal of Sedimentology Petrology, 36, 1149-1152.

El-Shahat, A. 1977. Petrography and Geochemistry of a Limestone-Shale Sequence with Early and Late Lithification: the Middle Purbeck of Dorset, England. Unpublished Ph.D. thesis, Southampton Univ., 358pp.

El-Shahat, A. and West, I.M. 1982. Early and late lithification of Aragonite Bivalve Beds in the Purbeck Formation (Upper Jurassic - Lower Cretaceous of Southern England). Sedimentary Geology, 35: 15-41.

Fuchtbauer, H. and Goldschmidt, H. 1964. Aragonitische Lumachellen im bituminosen Wealden des Emslandes. Beitr. Mineral. Petrogr., 10, 184-197.

Hudson, J.D. 1962. Pseudo-pleochroic calcite in recrystallised shell limestones. Geological Magazine,99, 492-500.

Maliva, R.G. and Dickson, J.A.D. 1992. The mechanism of skeletal aragonite neomorphism - evidence from neomorphosed mollusks from the upper purbeck formation (late Jurassic-early Cretaceous), southern England. Sedimentary Geology, 76, No.3-4 pp. 221-232

Dinosaurs and Dinosaur Footprints

Go to Purbeck Dinosaurs and other Vertebrates

Dirt Beds (Palaeosols) - General

(Purbeck fossil soils - see also Palaeosols)

Andrews, J.E. 1988. Soil-zone microfabrics in calcrete and in desiccation cracks from the Upper Jurassic Purbeck Formation of Dorset. Geological Journal, 23, 261-270. Alveolar septal structure, needle fibre, desiccation cracks, calcrete.

Astin, T.R. 1987. Petrology (including fluorescence microscopy) of cherts from the Portlandian of Wiltshire, U.K. - evidence of an episode of meteoric water circulation. Pp. 73-85 in Marshall, J.D. Diagenesis of Sedimentary Sequences. Geological Society Special Publication. No. 36, 73-85. Some carbonate grain dissolution prior to silicification. Chicksgrove Plant Bed. Wockley Member. Purbeck dirt bed. Vale of Wardour.

Francis, J.E. 1983. The Fossil Forests of the Basal Purbeck Formation (Upper Jurassic) of Dorset, Southern England. Ph.D. Thesis (unpublished), University of Southampton.

Francis, J.E. 1984. The seasonal environment of the Purbeck (Upper Jurassic) fossil forests. Palaeogeography, Palaeoclimatology, Palaeoecology, 48, 285-307.

Francis, J.E. 1986. The calcareous paleosols of the basal Purbeck Formation (Upper Jurassic), southern England. 112-138 in Wright, V.P. 1986. Paleosols: Their Recognition and Interpretation. Blackwell Scientific Publications, Oxford. 315p.

West, I.M., Shearman, D.J. and Pugh, M.E., 1969. Whitsun Field Meeting in the Weymouth Area, 1966. Proceedings of the Geologists' Association , 80, 331-340.

West, I.M., 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association., 86, 205-225.

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium "Sedimentation Jurassique W. Europeen." A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

Ali, Y.A.A., West, I.M. and Hilmy, M. 1981. Modern sabkha sediments and gypsum nodules from the Mediterranean coast of Egypt. Second Scientific Conference of Egyptian Postgraduates Abroad. p.136-151, 1981.

El-Shahat, A. and West, I.M. 1982. Early and late lithification of Aragonite Bivalve Beds in the Purbeck Formation (Upper Jurassic - Lower Cretaceous of Southern England). Sedimentary Geology, 35: 15-41.

Dirt Beds - Pebbles

(See also Black Pebbles)

Francis, J.E. 1983. The Fossil Forests of the Basal Purbeck Formation (Upper Jurassic) of Dorset, Southern England. Ph.D. Thesis (unpublished), University of Southampton.

Francis, J.E. 1986. The calcareous paleosols of the basal Purbeck Formation (Upper Jurassic), southern England. 112-138 in Wright, V.P. 1986. Paleosols: Their Recognition and Interpretation. Blackwell Scientific Publications, Oxford. 315p.

Perry, C.T. 1994. Freshwater tufa stromatolites in the Lower Purbeck Beds (Upper Jurassic), Isle of Portland, Dorset. Geological Journal, 29, 1129-135.

Dorset Purbecks, General

( a small selection of general references on the Dorset Purbecks and some of which may not be listed elsewhere)

(See also Purbeck - General)

House, M. R. 1989. Geology of the Dorset Coast. Geologists' Association Guide, 162pp and 34 plates.

House, M. R. 1993. Geology of the Dorset Coast. Geologists' Association Guide, 164 pp. and 32 plates. Second Edition.

Oppe, E.F. 1954. Through to Swanage. (A holiday guide pamphlet with geology). .

Sellwood, B., Wilson, C. and West, I.M. 1990. Jurassic Sedimentary Environments of the Wessex Basin. 13th International Sedimentological Congress Field Trip A16 - Guide, 89p. Nottingham.

Strahan, A. 1898. The Geology of the Isle of Purbeck and Weymouth. Memoirs of the Geological Survey, England and Wales. 278pp.

West, I.M., Shearman, D.J. and Pugh, M.E., 1969. Whitsun Field Meeting in the Weymouth Area, 1966. Proceedings of the Geol. Association , 80, 331-340.

West, I.M., 1969. Contribution in "International Field Symposium on the British Jurassic; Guide for Dorset and South Somerset". Ed. H.S. Torrens, A60-61.

Wilson, R.C.L., West, I.M. and Sellwood, B.W., 1983. Post-Congress Geological Tour D - Dorset. 11th World Petroleum Jubilee Congress, 58 pp.

West, I.M., 1988. Notes on some Purbeck sediments associated with the dinosaur footprints at Sunnydown Farm, near Langton Matravers, Dorset. Proceedings of the Dorset Natural History Arch. Society , 109, 153-154.

Sellwood, B., Wilson, C. and West, I.M. 1990. Jurassic Sedimentary Environments of the Wessex Basin. 13th International Sedimentological Congress Field Trip A16 - Guide, 89p. Nottingham.

West, I.M., 1992. Contribution on Purbeck Formation in: Cope, J.C.W., Ingham, J.K. and Rawson, P.F. (editor). 1992. Atlas of Palaeogeography and Lithofacies. Geological Society of London.

Wilson, V., Welch, F. B. A., Robbie, J.A. and Green, G.W. 1958. Geology of the Country around Bridport and Yeovil. Memoirs of the Geological Survey of Great Britain, Explanation of sheets 327 and 312. 118-129. Ostracod zones given.

Woodward, H.B.1895. The Jurassic Rocks of Britain. Vol 5. The Middle and Upper Oolitic Rocks of England (Yorkshire excepted). Memoirs of the Geological Survey of the United Kingdom. 499pp. and Libr.

Durlston Bay, Swanage.

Type Section

English Channel, - Purbeck Formation beneath the -

Hamblin, R.J.O., Crosby, A., Balson, P.S., Jones, S.M., Chadwick, R.A., Penn, I.E. and Arthur, M.J. 1992. The Geology of the English Channel. British Geological Survey, United Kingdom Offshore Regional Report, London, H.M.S.O., 106 pp., ISBN - 0-11-884490-3. P. 52 et seq. - Portland and Purbeck Beds. South of the Hampshire Dieppe High - To the south the strata become thinner and mid-way to the Central English Channel High comprise 10 or 20 m of sandy glauconitic limestone or calcareous mudstone beneath 60 or 70m of typical Purbeck Beds in which the anhydrite of the basal beds is locally replaced by calcite. Hampshire-Dieppe High. The Portland Beds thin westwards from the Isle of Purbeck to Ringstead. This is probably oblique to attentuation on the Hampshire-Dieppe High. These beds are largely absent along the core of the Hampshire Dieppe structure. Locally as in well 99/18-1, 54 m of Purbeck Beds rest on 5 m of Portland Limestone.

Lake, R.D. and Shephard-Thorn, E.R. 1988. Wealden and Purbeck Beds strata exposed in cliff sections, surface exposures and underground workings in the Hastings-Dungeness district.(sheets 320/321), wth an account of the sea-bed geology east of Dungeness. 99pp., British Geological Survey, Technical Report, Onshore Geology Series WA/88/6.

Euestheria (Estheria, conchostrocans) Chen, P.J. and Hudson, J.D. 1991. The conchostracan fauna of the Great Estuarine Group, Middle Jurassic, Scotland. Palaeontology, 34, 515-545. Abstract: The Great Estuarine Group contains the most diverse conchostracan fauna so far described from the Jurassic or Cretaceous of Europe, comprising twelve species in seven genera. Estheria murchisoniae Jones was described in the last century; it is now referred to Pseudograpta Novojilov and is the youngest member (latest Bathonian?) of the fauna described here. Euestheria trotternishensis and Neopolygrapta lealtensis spp. nov. occur near the base of the Great Estuarine Group and probably close to the Bajocian-Bathonian boundary. Dendrostracus hebridesensis sp. nov. occurs towards the top of the Kildonnan Member, Lealt Shale Formation. In the overlying Lonfearn Member, Skyestheria intermedia sp. nov. appears (probably descended from Neopolygrapta) and itself gives rise to Antronestheria praecursor sp. nov. The higher parts of the Great Estuarine Group, including most of the Kilmaluag Formation, are dominated by Antronestheria kilmaluagensis sp. nov., with one occurrence of Fibrestheria puncta sp. nov. The Pseudograpta fauna (containing P. orbita Chen, P. morrisi sp. nov., P. jonesi sp. nov. and P. murchisoniae (Jones)) occurs in beds probably near the top of the Kilmaluag Formation. All the conchostracans inhabited shallow, freshwater to oligohaline, near-coastal, lagoons. Biogeographic comparisons with China show that the earlier faunas were distinct in the two areas, but the Pseudograpta fauna occurs in both. Details of the construction of conchostracan growth bands are revealed by stereo scanning electron micrographs. End of Abstract. [The occurrence of conchostrans in the Purbeck is mentioned only briefly.]
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Francis , J.E. 1983. The Fossil Forests of the Basal Purbeck Formation, Upper Jurassic) of Dorset, Southern England: Palaeobotanical and Palaeoenvironmental Investigations. Unpublished Ph.D. thesis, Southampton University, 295pp.
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Jones , T.R. 1890. On some fossil Estheriae: B. Purbeck Estheriae. Geological Magazine, vol. 7, 385-390. [Euestheria]

Evaporites - Purbeck, General

Benismail , M.H. jn. 1991. Jurassic evaporitic deposits in southern Tunisia - a climatically and tectonically controlled sedimentation. Journal of African Earth Sciences and the Middle East, vol. 12, no. 1-2.

Brown, P.R. 1964. Petrography and origin of some upper Jurassic beds from Dorset, England. Journal. Sedimentary Petrology, 34, 254-269.

Brown, P.R. 1961. Petrology of the Lower and Middle Purbeck Beds of Dorset. Unpublished Ph.D. thesis, Liverpool University, 205p.

Ensom, P.C. 1989. A pseudomorph of calcite after halite from the Shrimp Bed, Portland Stone, at Swanworth Quarry, near Worth Matravers, Dorset. Proceedings of Dorset Natural History and Archaeological Society, 110, p.167.

Folk, R.L. and Pittman, J.S. 1971. Length-slow chalcedony: a new testament for vanished evaporites. Journal of Sedimentary Petrology.

Papioanou, F.P. and Carotsieris, Z. 1993. Dolomitization patterns in Jurassic-Cretaceous dissolution-collapse breccias of alon Mountain (Tripolis Unit, central Peloponnesus - Greece). Carbonates and Evaporites, vol.8, No.1, pp. 9-22

Platt, N.H. 1991. Lacustrine carbonates and pedogenesis: sedimentology and origin of palustrine deposits from the Early Cretaceous Rupelo Formation, W. Cameros Basin, N. Spain. Reprinted from Sedimentology, 1989, 665-684. Pages 323-342 in the present book. In: Wright, V.P. and Tucker, M.E. 1991. Calcretes. International Association of Sedimentologists, Reprint Series, 2, 352. Blackwell Scientific Publications. Oxford. [Charophytes, ostracods, gastropods and rare vertebrates. Silicified evaporites found near the top of the sequence. Stable isotope analysis. del 13C for -7 to -11 and del 18 O from -3 to -7.5. Palustrine limestones formed through pedogenic modification of lake carbonate. Low gradient, low energy, unstratified lake. Berriasian. Dark intraclasts like black pebbles.]

Shearman, D.J.1966. Origin of marine evaporites by diagenesis: Institute of Mining and Metallurgy, Transactions, 75, B 717, 208-215.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

Evaporites - Dorset - General

Brown, P.R. 1964. Petrography and origin of some upper Jurassic beds from Dorset, England. Journ. Sedim. Petrology, 34, 254-269. This and his 1963 algal paper summarises his thesis.

Brown, P.R. 1961. Petrology of the Lower and Middle Purbeck Beds of Dorset. Unpublished Ph.D. thesis, Liverpool University, 205p. Studied Dorset sections and Portsdown Borehole. A selection of samples and thin-sections is held at Liverpool University.

Ensom, P.C. 1989. A pseudomorph of calcite after halite from the Shrimp Bed, Portland Stone, at Swanworth Quarry, near Worth Matravers, Dorset. Proceedings of Dorset Natural History and Archaeological Society, 110, p.167.

House, M. R. 1989. Geology of the Dorset Coast. Geologists' Association Guide, 162pp.

West, I.M., 1960. On the occurrence of celestine on the Caps and Broken Beds at Durlston Head, Dorset. Proceedings of the Geologists' Association, London, 71, 391-401.

West, I.M., 1964. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Proceedings of Yorkshire Geological Society 34, 315-330.

West, I.M., 1965. Macrocell structure and enterolithic veins in British Purbeck gypsum and anhydrite. Proceedings of Yorkshire Geological Society , 35, 47-58.

Salter, D.L. and West, I.M., 1965. Calciostrontianite in the basal Purbeck Beds of Durlston Head, Dorset. Mineralogical Magazine, 35, 146-150.

West, I.M., Shearman, D.J. and Pugh, M.E., 1969. Whitsun Field Meeting in the Weymouth Area, 1966. Proceedings of the Geologists' Association , 80, 331-340.

West, I.M., 1973. Vanished evaporites - significance of strontium minerals. Journal of Sedimentary Petrology, 43, 278-279.

West, I.M., 1974. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Reprinted in Kirkland and Evans (Ed.): Marine Evaporites, Origin, Diagenesis and Geochemistry.

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium "Sedimentation Jurassique W. Europeen." A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

Evaporites - Anhydrite

Holliday, D.W. and Shephard-Thorn, E.R. 1974. Basal Purbeck evaporites of the Fairlight Borehole, Sussex. Institute of Geological Sciences, Report No. 74/4.

Holliday, D.W. 1973. Early diagenesis in nodular anhydrite rocks. Transactions of the Institute of Mining and Metallurgy., 82, B81-4.

Salter, D.L. and West, I.M., 1965. Calciostrontianite in the basal Purbeck Beds of Durlston Head, Dorset. Mineralogical Magazine, 35, 146-150.

Shearman, D.J.. (1966) Origin of marine evaporites by diagenesis: Institute of Mining and Metallurgy, Transactions, 75, B 717, 208-215.

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium "Sedimentation Jurassique W. Europeen." A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

West, I.M., 1973. Vanished evaporites - significance of strontium minerals. Journal of Sedimentary Petrology, 43, 278-279.

West, I.M., 1965. Macrocell structure and enterolithic veins in British Purbeck gypsum and anhydrite. Proceedings of Yorkshire Geological Society, 35, 47-58.

West, I.M., 1964. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Proceedings of Yorkshire Geological Society, 34, 315-330.

West, I.M., 1974. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Reprinted in Kirkland and Evans (Ed.): Marine Evaporites, Origin, Diagenesis and Geochemistry.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

Evaporites - Anhydrite, Deformation, Flow etc.
.
Muller, W.H., Schmid, S.M. and Briegel, U. 1981. Deformation experiments on anhydrite rocks of different grain sizes: rheology and microfabrics. Tectonophysics, 78, 527-544. [Muller, Schmidt and Briegel (1981) noted that anhydrite begins to deform and flow under geological reasonable strain rates at between 150 and 180° C. These temperatures are normally only reached at depths of 4 - 6 km. Reference in Bell, 1989. The Purbecks are not referred to but this paper is important regarding the anomaly of deformed anhydrite at Durlston Head. Vitrinite reflectance does not suggested such high temperatures.]

Evaporites - Calcitisation
.
Ensom, P.C. 1989. A pseudomorph of calcite after halite from the Shrimp Bed, Portland Stone, at Swanworth Quarry, near Worth Matravers, Dorset. Proceedings of Dorset Natural History and Archaeological Society, 110, p.167.
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West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium "Sedimentation Jurassique W. Europeen." A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

Evaporites - Correlation

Allen, P. and Wimbledon, W.A. 1991. Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas. Cretaceous Research, 12, 511-526. . Keywords - Germany, dating, France, clays, " Event stratigraphy is used with caution .... Thus .. gypsum near the base of the sequence might not have been generated by a regional climatic event. Likewise transgression-regression phases do not necessarily reflect eustatic changes of sea-level."
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Carozzi, A. 1948. Etude Stratigraphique et Micrographique du Purbeckien du Jura Suisse. Faculte des Sciences, Universite de Geneve, 175 pp. Stratigraphic and Micrographic Study of the Purbeckian of the Swiss Jura. Thesis presented at the Faculty of Sciences at Geneva University for degree of Doctor of Science in Geology and Mineralogy. Thesis No. 1122. This work is in printed and published paperback book format. [This is a classic, early, petrographic study of the Purbeck Formation, with quantitative data. Extract (which I have translated from the French): "The Purbeckian of the Swiss Jura presents two palaeogeographic domains that are quite distinct, already in part delimited by Maillard. The most extensive is the domain of the Lower Dolomitic Beds which covers the Vaudois Jura and the southern part of the Neuchatelois Jura and the Jura Bernois Jura. From the bottom to top there are 1. The Lower Dolomitic Beds (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), and 3. Upper Brackish or Upper Marine (Upper Purbeck)...
To the north of this zone in the heart of the Neuchatelois Jura is the domain of the marls with gypsum. The type succession is from bottom to top: 1. Marls with Gypsum (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), Upper Brackish or Marine Beds (Upper Purbeck)."
[A variety of interesting Purbeck topics are discussed including the Black Pebbles, the multicoloured breccio-conglomerates, the source of Mg, the charophytes, ostracods, the grumeleux limestones (also common in Dorset), the dolomites (cf. the Lower Purbeck dolomitic marls of Dorset), pelletoidal limestones ("pseudo-ooliths"), microbreccias, cargneules, celestite, gastropods, Dasycladiaceans (not present in Dorset), cylces of sedimentation, and faecal pellets. It has many graphic logs and maps and a good bibliography of the older Purbeck literature, much of which is not listed here. An important aspect is that Carozzi related Purbeck facies to palaeotectonics, with the dolomite facies of the Lower Purbeck girdling the gypsum facies which mostly occurs on the structural highs. The Dorset Purbeck is also, of course, affected by palaeotectonics - the well-known, Late Kimmerian. However, thickness variations are rather most noticeable in Dorset than the facies variations. Carozzi does not discuss the Dorset succession, but his work is useful for comparative purposes. Carozzi's thesis is an old classic and recommended reading for Dorset Purbeck enthusiasts.]

Evaporites - Chile

(approximately equivalent in age to the Purbecks)

Bell, C.M. 1989. Saline lake carbonates within an Upper Jurassic -Lower Cretaceous red sequence in the Atacama region of northern Chile. Sedimentology, 36, 651-663. The laterally extensive, 3 m thick, Codocedo Limestone Member within red beds of the Upper Jurassic - Lower Cretaceou Quebrada Monardes Formation in the Atacama region of northern Chile. Vertical accretion within a perenial saline lake. A few dinosaur bones and silicified tree trunks at one location. Centimetre-scale beds of evaporitic gypsum, anhydrite and halite now extensively replaced by calcite, chalcedony and quartz. Geodes and gypsum pseudomorphs in the overlying siltstone and sandstone. Brecciated zones occur (cf. Purbeck Broken Beds). Net-texture, lutecite, pseudomorphs after anhydrite. Laminites. Miliolid foraminifera. Association of folds with brecciation. Muller, Schmidt and Briegel (1981) noted that anydrite begins to deform and flow under geologically reasonable strain rates at 150 and 180° C. These temperatures are normally only reached at depths of 4-6 km but in the Codocedo Member, possibly with an overburden of no more than 1 km, a much higher geothermal gradient is suggested by the interstratified lava flows. Some comparison with Purbecks.

Evaporites - Diagenesis

Salter, D.L. and West, I.M., 1965. Calciostrontianite in the basal Purbeck Beds of Durlston Head, Dorset. Mineralogical Magazine, 35, 146-150.

Shearman, D.J. 1966 Origin of marine evaporites by diagenesis: Institute of Mining and Metallurgy, 75, B 717, 208-215.

West, I.M., 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geol. Ass., 86, 205-225.

West, I.M. 1979. Sedimentary Environments and Diagenesis of Purbeck Strata (Upper Jurassic - Lower Cretaceous) of Dorset, U.K. Unpublished Ph.D. Thesis, Southampton University, 181 p.

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium "Sedimentation Jurassique W. Europeen." A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

West, I.M., 1974. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Reprinted in Kirkland and Evans (Ed.): Marine Evaporites, Origin, Diagenesis and Geochemistry.

West, I.M., 1964. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Proceedings of the Yorks. Geological Society 34, 315-330.

West, I.M., 1960. On the occurrence of celestine on the Caps and Broken Beds at Durlston Head, Dorset. Proceedings of the Geol. Association 71, 391-401.

West, I.M., 1965. Macrocell structure and enterolithic veins in British Purbeck gypsum and anhydrite. Proceedings of the Yorks. Geol. Society , 35, 47-58.

West, I.M., 1973. Vanished evaporites - significance of strontium minerals. J. Sedimentary Petrology, 43, 278-279.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

Evaporites - Enterolithic Veins

Holliday, D.W. 1973. Early diagenesis in nodular anhydrite rocks. Transactions of the Institute of Mining and Metallurgy., 82, B81-4.

West, I.M. 1964. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Proceedings of the Yorkshire Geological Society, 34, 315-330.

West, I.M. 1965. Macrocell structure and enterolithic veins in British Purbeck gypsum and anhydrite. Proceedings of Yorkshire Geological Society, 35, 47-58.

Evaporites - Germany

Van Voorthuysen, J.H. 1951. Anhydrite formation in the saline facies of the Münder Mergel (Upper Malm). Geol. Mijnbouw, 1951, 13, No.8, (anhydrite ooids). German equivalent of the British Purbecks.

Evaporites - Nodular

Holliday, D.W. 1973. Early diagenesis in nodular anhydrite rocks. Transactions of the Institute of Mining and Metallurgy, 82, B81-4.

West, I.M. 1965. Macrocell structure and enterolithic veins in British Purbeck gypsum and anhydrite. Proceedings of Yorkshire Geological Society, 35, 47-58.

Evaporites - Sussex

British Gypsum Limited. 1989. Our Company goes back a long way. Brochure.

Holliday, D.W. and Shephard-Thorn, E.R. 1974. Basal Purbeck evaporites of the Fairlight Borehole, Sussex. Institute of Geological Sciences, Report No. 74/4.

Holliday, D.W. 1973. Early diagenesis in nodular anhydrite rocks. Transactions of the Institute of Mining and Metallurgy, 82, B81-4.

Howitt, F. 1964. Stratigraphy and structure of the Purbeck inliers of Sussex (England). Quarterly Journal of the Geological Society, London, 120, 77-113.

Lake, R.D. and Shephard-Thorn, E.R. 1988. Wealden and Purbeck Beds strata exposed in cliff sections, surface exposures and underground workings in the Hastings-Dungeness district (sheets 320/321), with an account of the sea-bed geology east of Dungeness. 99pp., British Geological Survey, Technical Report, Onshore. Geology. Series. WA/88/6.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

Extinction - Jurassic Cretaceous Boundary

Smith, G. 1996. Studies on the postulated Jurassic-Cretaceous boundary mass extinction. Palaeontological Association Newsletter No. 32, Abstracts for Annual Meeting for 1996. Marine sequences show that there is an extinction peak. Evidence from Volga Basin and Carvaca in S.E. Spain.

Field Guides

Clements, R.G. 1993. Type-section of the Purbeck Limestone Group, Durlston Bay, Swanage, Dorset. Proceedings of the Dorset Natural History Arch. Society , 114 for 1992, 181-206. Classic section log.

House, M.R. 1958. The Dorset Coast from Poole to the Chesil Beach. Guide of the Geologists' Association , Benham and Co. Ltd., Colchester. See later guides of House (1989; 1993).

House, M. R. 1989. Geology of the Dorset Coast. Geologists' Association Guide, 162pp and 34 plates.

House, M. R. 1993. Geology of the Dorset Coast. Geologists' Association Guide, 164 pp. and 32 plates. Second Edition.

Taylor, P.D. (Ed.) 1996. Field Geology of the British Jurassic. 286p. The Geological Society of London. ISBN - 1-897799-41-1 Softback. List price £65. Members of Geological Society £29. Review by Kelly, R.A. in Palaeontology Newsletter No. 31, 1996. Some notes from this follow: Excursion guides relating to the 1993 W.J. Arkell Symposium held in London. Collection of eight articles covering these areas. 1. Cope introduces British Jurassic and points out importance re Tethyan-Boreal correlations. Clear cut base within Blue Lias but poorly defined boundary at top in Purbeck. 75 ammonite zones. Bononian Stage (up.Kim.) reappears. Excursions - Warrington and Ivimey Cook, Triassic and Jurassic of Somerset and South Wales, Mudge, Middle Jur of Cotswolds, Callomon and Cope, 1996, Jurassic of Dorset coast ; H Hesselbo and Jenkins, Hetangian to Bajocian, Coe, Oxfordian, Rawson and Wright, Jurassic of Cleveland Basin, Morton and Hudson, Jurassic of Raasay and Skye. Second edition is recommended.

West, I.M., Shearman, D.J. and Pugh, M.E., 1969. Whitsun Field Meeting in the Weymouth Area, 1966. Proceedings of the Geol. Association , 80, 331-340.

West, I.M., 1969. Contribution in -International Field Symposium on the British Jurassic; Guide for Dorset and South Somerset -. Ed. H.S. Torrens, A60-61.

Wilson, R.C.L., West, I.M. and Sellwood, B.W., 1983. Post-Congress Geological Tour D - Dorset. 11th World Petroleum Jubilee Congress, 58 pp.

Sellwood, B., Wilson, C. and West, I.M. 1990. Jurassic Sedimentary Environments of the Wessex Basin. 13th International Sedimentological Congress Field Trip A16 - Guide, 89p. Nottingham.

West, I. 1992. Excursion A3. Sedimentology of the Lower Purbeck Formation at Lulworth Cove and the Isle of Portland. B.S.R.G. 1992. Field Excursion Guides, Department of Oceanography, University of Southampton. pp. 36-51. ISBN 0 -85432-4623. First Published in 1992 by the Department of Oceanography, University of Southampton for and on behalf of the British Sedimentological Research Group.

Field Trip Reports

Arkell, W.J. 1934. Whitsun Field Meeting. The Isle of Purbeck. Proceedings of the Geologists' Association , 45 , 412-419. Durlston Bay - briefly, Tilly Whim Caves etc.

Fish

Griffith, J. and Patterson, C. 1963. The structure and relationship of the Jurassic fish Ichthyokentema purbeckensis. Bulletin of the British Museum (Natural History), Geology Series, Vol. 8, No. 1. [A marine fish possibly adapted to hypersaline conditions and found in the upper (moderately hypersaline) part of the Broken Beds. Found at the Fossil Forest locality and elsewhere. Compare with the hypersaline facies for the upper Broken Beds of West (1975).]

Patterson, C. 1966. British Wealden Sharks. Bulletin of the British Museum, Natural History, 11, No. 7. 283-350 and plates.

Woodward, A.S. 1889. Catalogue of the Fossil Fishes in the British Museum (Natural History). 1, xlvii + 474 pp. 17pls. British Museum (Natural History ), London.

Woodward, A.S. 1916. The Fossil Fishes of the Wealden and Purbeck Formations. Part 1. Monograph of the Palaeontographical Society, London, 1916, 1-48, pls. 1-10.

Woodward, A.S. 1919. The Fossil Fishes of the Wealden and Purbeck Formations. Part 3. Monograph of the Palaeontographical Society, London, 1919, 105-148, pls. 21-26.

Fluid Flow

(regarding Durlston Head Broken Beds etc.)

Alexander, J., Black, J.H. and Brightman, M.A. 1987. The role of low-permeabilty rocks in regional flow. In Goff, J.C. and Williams, B.P.J. 1987. Fluid Flow in Sedimentary Basins and Aquifers. Geological Society Special Publication No. 34, Geological Society, London., 230p. [See pp.173-183. In sedimentary basins there is subhorizontal flow -throughflow - in high permeability rocks and vertical flow across intervening mudrocks (crossflow). Faults as features of high permeability effectively shield the centre of the basin from the high heads associated with the basin margins and reduce overall head gradients. Channelled flow is an attractive mechanism for flow through mudrocks containing evaporites. I think that basinward throw flow in the Portland Stone with crossflow through the Purbecks at the Durlston Head fault and perhaps channelled flow in the evaporites might explain the Durlston Head celestite etc. Perhaps this occurred in the Cretaceous when the basinward flow would have been southward.]

Chapman, R.E 1987. Fluid flow in sedimentary basins: a geologist's perspective. Pp. 3-18 in Goff, J.C. and Williams, B.P.J. 1987. Fluid Flow in Sedimentary Basins and Aquifers. Geological Society Special Publications No. 34, Geological Society, London, 230p. .

Downing, R.A., Edmunds, W.M. and Gale, I.N. 1987. Regional groundwater flow in sedimentary basins in the U.K. pp 105-125 in Goff, J.C. and Williams, B.P.J. 1987. Fluid Flow in Sedimentary Basins and Aquifers. Geological Society Special Publications, No. 34, Geological Society, London, 230p.

Goff, J.C. and Williams, B.P.J. 1987. Fluid Flow in Sedimentary Basins and Aquifers. Geological Society Special Publication No. 34, Geological Society, London, 230p. .

Foraminifera

(Note - Foraminifera are relatively rare in the lagoonal and lacustrine Purbeck Formation)

Radley, J.D. Unpub. 1993. Occurrence of foraminifera in the Portland Stone (Portlandian, Upper Jurassic) of Holworth House, Ringstead. 3p. for Proceedings of the Dorset Natural History and Archaeological Society. Purbeck specimens were not mentioned.

Radley, J.D. 1993. An occurrence of Ammobaculites (Foraminiferida, Lituolacea) in the Purbeck Formation (late Jurassic-early Cretaceous) of Dorset, south-west England. Journal of Micropalaeontol, 12, 119-120. Authors abstract: An influx of Ammobaculites cf. obliquus Loeblich and Tappan is documented from the late Jurassic-early Cretaceous Purbeck Formation of Dorset, south-west England. The foraminifera are interpreted as inhabitants of a dysaerobic, muddy, brackish lagoonal environment. Known in the Hauterivian, Valangianian. Also occurs in the Barremian Vectis Formation. Modern forms occur in brackish lagoons of 12.5 to 15 parts per thousand salinity although they tolerate salinity fluctuations. Sometimes inhabit poorly oxygenated mud. A section of the Wimbledon Durlston log is given, although I usually use the well-known Clements' log. Foraminifera are in Clements DB 168.

Fossil Forests And Fossil Trees

Abineri, K.W. 1989. Photomicrographs of cellulose peels from the Mesozoic rocks of Dorset. Proceedings of the Geologists' Association, 100, 161-174.

Andrews, J.E. 1988. Soil-zone microfabrics in calcrete and in desiccation cracks from the Upper Jurassic Purbeck Formation of Dorset. Geological Journal, 23, 261-270. Alveolar septal structure, needle fibre, desiccation cracks, calcrete.

Arkell, W.J. 1947. The Geology of the Country around Weymouth, Swanage, Corfe and Lulworth. Memoir of the Geological Survey, 386 pp.

Astin, T.R. 1987. Petrology (including fluorescence microscopy) of cherts from the Portlandian of Wiltshire, U.K. - evidence of an episode of meteoric water circulation. Pp. 73-85 in Marshall, J.D., Diagenesis of Sedimentary Sequences. Geological Society Special Publication, No. 36, 73-85. Some carbonate grain dissolution prior to silicification.

Buckland, W. 1829. On the Cycadeoideae, a family of fossil plants found in the oolite quarries of the Isle of Portland. Transactions of the Geological Society, London, 2, 395-401.

Buckland, W. and De La Beche, H.T. 1836. On the geology of the neighbourhood of Weymouth and the adjacent parts of the coast of Dorset. Transactions of the Geological Society, London, 4, 1-46.

Chaloner, W.G. and Creber, G.T. 1990. Do fossil plants give a climatic signal? Journal of the Geological Society , London, 147, 343-350.

Creber, G.T. and Francis, J.E. 1987. Productivity in fossil forests. In: Jacoby, G.C. (ed.), Proceedings of the International Symposium on ecological aspects of tree ring analysis. U.S. Department of Energy, Washington, D.C., 319-326.

Damon ,R.F., 1884. Geology of Weymouth, Portland and the Coast of Dorsetshire from Swanage to Bridport-on- the-Sea: with Natural History and Archaeological Notes. 2nd ed., R.F.Damon, Weymouth, 250 pp. Discussion and illustrations regarding cycadophytes etc.

Francis, J.E. 1983. The dominant conifer of the Jurassic Purbeck Formation, England. Palaeontology, London, 26, 277-294. Protocupressinoxylon purbeckensis.

Francis, J.E. 1983b. The Fossil Forests of the Basal Purbeck Formation, Upper Jurassic) of Dorset, Southern England: Palaeobotanical and Palaeoenvironmental Investigations. Unpublished Ph.D. thesis, Southampton Univ., 295pp.

Francis, J.E. 1984. The seasonal environment of the Purbeck (Upper Jurassic) fossil forests. Palaeogeography, Palaeoclimatology, Palaeoecology, 48, 285-307.

Francis, J.E. 1986. The calcareous paleosols of the basal Purbeck Formation (Upper Jurassic), southern England. 112-138 in Wright, V.P. 1986. Paleosols: Their Recognition and Interpretation. Blackwell Scientific Publications, Oxford. 315p.

Francis, J.E. 1990. (On high latitude fossil plants). Geology Today.

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Pearce , C.R., Hesselbo, S.P. and Coe, A.L. 2005. The mid-Oxfordian (Late Jurassic) positive carbon-isotope excursion recognised from fossil wood in the British Isles. Palaeogeography, Palaeoclimatology, Palaeoecology, 221, Issues 3-4, 343-357. By Christopher R. Pearce, , Stephen P. Hesselbo, and Angela L. Coe. Abstract: The carbon-isotope ratios of fossil wood have recently been confirmed as a proxy for changes in the isotopic composition of palaeoatmospheres. Carbon-isotope data from fossil wood samples collected from the Jurassic (Oxfordian) Staffin Shale Formation on the Isle-of-Skye, Scotland (Boreal/Sub-Boreal ammonite zonation) reveal a long-term positive carbon-isotope excursion of at least 3‰. This excursion reaches a maximum in the mid-Oxfordian, and closely matches the carbon-isotope ratios previously reported from belemnites collected from the same section and carbon-isotope data from carbonates in other European sections. This confirms that the mid-Oxfordian positive carbon-isotope excursion affected the total exchangeable carbon reservoir. Fossilised wood samples collected at a higher stratigraphic resolution, but over a shorter interval from the Corallian Group in Dorset, England (antecedens, parandieri and cautisnigrae subzones; NW European ammonite zonation) show considerable scatter in their carbon-isotope ratios, and no trends are discernable. The combined Isle-of-Skye and Dorset dataset shows that the long-term Oxfordian positive carbon-isotope trend coincides with a long-term relative sea-level change, and that the most positive carbon-isotope ratios occur across the plicatilis–transversarium biozonal boundary (Sub-Mediterranean ammonite zonation). This implies that the carbon-isotope excursion was not caused by the well-documented rise in sea-level in the transversarium Zone. Although very low carbon-isotope ratios from fossil wood samples are recorded from the Nodular Rubble Member (parandieri Subzone) of Dorset, there is not a sufficiently coherent signal to ascribe these values to the gas–hydrate dissociation event previously hypothesized from the carbon-isotope ratios of Tethyan marine carbonates. A microscopal analysis of the charcoalified debris from the Staffin Shale Formation indicates a prevalence of the wood genus Cupressinoxylon [the Purbeck fossil tree, described in the papers of Jane Francis], derived from a cheirolepidiaceaen conifer.
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Pugh, M.E. 1968. Algae from the Lower Purbeck limestones of Dorset. Proceedings of the Geologists' Association, 79, 513-523.
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Strahan, A. 1898. The Geology of the Isle of Purbeck and Weymouth. Memoirs of the Geological Survey, England and Wales. 278pp.
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Swinney, L. 1981. Portlander's garden of petrified plants. Dorset Evening Echo, 31.01.1981.

Vachrameev, V.A. 1970. Range and palaeoecology of Mesozoic conifers, the Cheirolepidaceae. Paleontological Journal., 1, 12-25.
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Watson, J. 1977. Some Lower Cretaceous conifers of the Cheirolepidaceae from the U.S.A. and England. Palaeontology, 20, 715-749.

Watson, J. and Alvin, K.L. 1999. The cheirolepidiaceous conifers Frenelopsis occidentalis Heer and Watsoniocladus valdensis (Seward) in the Wealden of Germany. Cretaceous Research, 20, 315-326. Abstract: The cheirolepidiaceous conifer Frenelopsis occidentalis Heer has been identified for the first time from the Wealden in the Lower Cretaceous of Germany. Proof of the occurrence of alternating whorls of three leaves in this species confirm its attribution to the genus Frenelopsis Schenk, which was previously tentative. Branches emerging in mid-internode are seen for the first time in F. occidentalis. A piece of a core from the Wilsnack 2 borehole contains short lengths of conifer shoots in which decurrent leaf bases are separated laterally by distinct sutures along the entire length of the internode. Most of the shoots display the opposite decussate leaf arrangement typical of the form-genus Cupressinocladus Seward but there is a single shoot in which the leaves occur in alternating whorls of three. The cuticle suggests identification with the species Cupressinocladus valdensis (Seward) from the English Purbeck and Wealden which has recently been reassigned to the newly erected cheirolepidiaceous genus Watsoniocladus Srinivasan.

Watson, J., Fisher, H.L. and Hall, N.A. 1988. The Holotype of the Wealden conifer Brachyphyllum punctatum Michael. Palaeontology, 31, 1029-1031.
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West , I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium - Sedimentation Jurassique W. Europeen. A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.
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Woodward, H.B.1895. The Jurassic Rocks of Britain. Vol 5. The Middle and Upper Oolitic Rocks of England (Yorkshire excepted). Memoirs of the Geological Survey of the United Kingdom. 499pp. .

Fossil Forests - Sandholes

(or chaff-holes of Quarrymen. Remains of branches in stromatolitic limestone. )

Francis, J.E. 1986. The calcareous paleosols of the basal Purbeck Formation (Upper Jurassic), southern England. 112-138 in Wright, V.P. 1986. Paleosols: Their Recognition and Interpretation. Blackwell Scientific Publications, Oxford. 315p. A tree at Chalbury Camp is shown with a side branch encased in algal limestone like a sandhole.

Fossil Forest - Analogues

a separate Pubeck Analogue Bibliography exists)

Bell, C.M. 1989. Saline lake carbonates within an Upper Jurassic -Lower Cretaceous red sequence in the Atacama region of northern Chile. Sedimentology, 36, 651-663. The laterally extensive, 3 m thick, Codocedo Limestone Member within red beds of the Upper Jurassic - Lower Cretaceou Quebrada Monardes Formation in the Atacama region of northern Chile. Silicified tree trunks at one location.

Renaut, R.W. 1990. Recent sedimentation in the saline, alkaline playa-lake basins of interior British Columbia, Canada. 13th International Sedimentological Congress, Nottingham, 455-6 (alkaline lakes surrounded by forest. dolomite magnesite etc.)

Schweingruber, F.H. 1993. Trees and Wood in Dendrochronology. Springer. 430 p.

Stein, C.L. 1982. Silica recrystallization in petrified wood. Journal of Sedimentary Petrology, 52, 1277-1282.

Friar Waddon

(Upwey area. See also Upwey and see Ridgeway)

Ensom, P.C. 1983. A temporary exposure in the Purbeck Limestone Formation (Upper Purbeck Beds) at Friar Waddon Pumping Station, Dorset. Proceedings of the Dorset Natural History and Archaeological Society 105, 89-91.

House, M.R. 1982. Unpublished notes. Sections at Upwey described briefly. With Ann Mather and the late Chris Sayer.

Whitaker, W. and Edwards, W. 1926. Wells and Springs of Dorset. Memoirs of the Geological Survey. 119 + xi pages. See Friar Waddon borehole, p. 74.

Frogs

Evans, S.E., Milner, A.R. and Mussett, F. 1990. A discoglossid frog from the Middle Jurassic of England. Palaeontology, 33, 299-311. Purbeck frog mentioned - Ensom discovery.

Gastropods

Arkell, W.J. 1947. The Geology of the Country around Weymouth, Swanage, Corfe and Lulworth. Memoir of the Geological Survey, 386 pp.

Bandel, K. 1991. Gastropods from brackish and fresh water of the Jurassic -Cretaceous transition (a systematic reevaluation). Berliner geowissenschaftliche abhandlungen, Reiche A, Band 134, Berlin, 1991, pp. 9-55. . MRH has original. Abstract: From the Purbeckian facies of the Upper Jurassic and Lowermost Cretaceous 23 species of gastropods that have lived in coastal swamps in brackish or fresh water have been studied. Special emphasis was placed on the morphology of their early ontogenetic shell. In many cases the shape and orientation of the first whorls of the shell could be utilized to find a more appropriate place within the system of gastropods than had been suggested before and correlate the fossil species with their modern relatives. The Purbeckian fauna is compared with the modern gastropods living in similar environment. End of authors abstract. Notes by IMW - Land snails are recorded from Switzerland. Some Hydrobias become Proauriculastra. Portesham charophyte chert referred to. Physa becomes Prophysa. Planorbic becomes Gyraulus. Some Jura Mountain sections described by Mojon (in a thesis) are given. They are quite detailed.

Clements, R.G. l969. Contribution to section on the Purbeck Beds : In : Guide for Dorset and South Somerset. In Torrens, H.S. (Editor) International Field Symposium on the British Jurassic. Keele University. 71 pp.

Clements, R.G. 1973. A Study of Certain Non-marine Gastropods from the Purbeck Beds of England. Ph.D. Thesis, University of Hull, 491 pp.

Gray, J. 1988. Evolution of the freshwater ecosystem: the fossil record. Palaeogeography, Palaeoclimatology, Palaeoecology, Special Issue, Aspects of Freshwater Paleoecology and Biogeography (Gray, J. editor), 62, 1-214 (mostly analogues)

Radley, J. 198? Purbeck and Portland Gastropods. M.Sc. Thesis. Extracts in . Full title not known. True low salinity gastropod faunas in vertual evolutionary stasis since their appearance in the Jurassic. Much Buckinghamshire information in thesis although only small amount in this extract. Aptyxiella portlandica - occurrence and mode of life. Micromorphic gastropod faunas of "algal meadows". Keywords - Valvata, Hydrobia, Natica, Bathrotomaria Aylesbury, Creamy Limestones Chilmark Tisbury Ragstones Shotover. .

Geochemistry- General

Harvey, C.O. 1953. In Summary of Progress of the Geological Survey of Great Britain for 1951. p. 64.

Harvey, C.O. and Wilson, A.D. 1958. Report of the Chemical and Spectographic Department. Summary of Progress of the Geological Survey. for 1957., 51-53. Boron content of the Purbeck rocks , p. 53.

Quest, M. (1985) Petrographic and Geochemical studies of the Portland and Purbeck Beds of Dorset, Unpublished Ph.D. Thesis, Geol. Dept., Univ. of Birmingham, England, 347pp.

Geochemistry - Isotopes

Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. Del 13C and del 18 O isotope data. Sr ppm. Sr high in subtidal facies.

Marshall, J. D. 1982. Isotopic composition of displacive fibrous calcite veins: reversal in pore-water composition trends during burial diagenesis. Journal of Sedimentary Petrology, 52, 0615-0630. .

Quest, M. (1985) Petrographic and Geochemical studies of the Portland and Purbeck Beds of Dorset, Unpublished Ph.D. Thesis, Geology Department, University of Birmingham, England, 347pp.

Geochemistry - Strontium

Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. Sr ppm. Sr high in subtidal facies.

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Germany

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Elstner, F. and Mutterlose, J. 1996. The Lower Cretaceous (Berriasian and Valanginian) in NW Germany. Cretaceous Research, 17, 119-133. Abstract: The non-marine sedimentary successions of the Berriasian and lower Valanginian of NW Germany are described. The stratigraphical distribution of ostracods allow this interval to be subdivided into 10 biozones, which can be used for regional correlation in the central part of the NW German Basin. Three ostracod taxa (Fabanella ansata, Cypridea alta formosa and Pachycytheridea compacta) can be used for interregional correlation between Germany, Denmark, France and England. The middle parr of the Katzberg Member, which yields F. ansata, allows correlation with the Lower Purbeck of S England, the Paris Basin, and the Boulonnais. The first occurrence of this species can be used to define the Portland/Purbeck boundary. Fluctuations in the taxonomic content of ostracod assemblages reflect changes in salinity. Brackish conditions dominated deposition during the earliest Berriasian (Munder Formation) and earliest Valanginian (Osterwald Member). Sediments of the late Berriasian Obernkirchen Member were deposited under freshwater conditions. A short-lived marine transgression marked the mid Berriasian (base Wealden 4). The Platylenticeras Beds of mid-Valanginian age indicate a return to fully marine conditions.
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Feist, M. and Schudack, M. 1991. Correlation of charophyte assemblages from the non-marine Jurassic-Cretaceous transition of NW Germany. Cretaceous Research, 12, 495-510.

Glaciation

Frakes, L.A. and Francis, J.E. 1988. A guide to Phanerozoic cold polar climates from high-latitude ice-rafting in the Cretaceous. Nature, 333, 547-549.

Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. Milankovitch cycles found by Fast Fourier Transform. Role of glacio-eustasy. See also Frakes and Francis 1988, Nature.

Halite

Brown, P.R. 1964. Petrography and origin of some upper Jurassic beds from Dorset, England. Journal of Sedimentary Petrology, 34, 254-269. Halite pseudomorphs in the Hard Cockle Beds etc.

Brown, P.R. 1961. Petrology of the Lower and Middle Purbeck Beds of Dorset. Unpublished Ph.D. thesis, Liverpool University, 205p. Halite pseudomorphs in the Cherty Freshwater Member etc.

Ensom, P.C. l985. An annotated section of the Purbeck Limestone Formation at Worbarrow Tout, Dorset. Proceedings of Dorset Natural History and Archaeological Society, Vol.106, pp. 87-91. Halite pseudomorphs in the Cherty Freshwater Member.

Ensom, P.C. 1989. A pseudomorph of calcite after halite from the Shrimp Bed, Portland Stone, at Swanworth Quarry, near Worth Matravers, Dorset. Proceedings of Dorset Natural History and Archaeological Society., 110, p.167.

House, M.R. 1966. Dorset Natural History Reports: Geology: (section on "Purbeck Beds" describing pellet moulds or pseudomorphs after halite). Proceedings of Dorset Natural History and Archaeological Society, 87, 33-34.

Meyer, C.J.A. 1872. On the Wealden as a Fluvio-Lacustrine Formation, and on the relation of the so-called "Punfield Formation" to the Wealden and Neocomian. Quarterly Journal of the Geological Society of London., 28, 243-555.

Radley, J.D. 1992. Halite pseudomorphs from the Cherty Freshwater Member (Purbeck Limestone Formation) of Lulworth Cove, Dorset. Pp in Natural History Reports, Geology, Proceedings of Dorset Natural History and Archaeological Society.

West, I. M. 1979. Sedimentary Environments and Diagenesis of Purbeck Strata (Upper Jurassic - Lower Cretaceous) of Dorset, U.K. Unpublished Ph.D. Thesis, Southampton University, 181pp.

Halite - Displacive Crystals Analogues

Handford, C.R. 1982. Terrigenous clastic and evaporite sedimentation in a Recent continental sabkha playa basin, Bristol Dry Lake, California. 65-74 in Handford, C.R., Loucks, R.G. and Davies, G.R.. Depositional and Diagenetic Spectra of Evaporites - A Core Workshop. S.E.P.M. Core Workshop No. 3, Calgary Canada - June 26-27, 1982. S.E.P.M. 395p. see p. 67.

History Of Research

Austen, J. H. 1852. A guide to the Geology of the Isle of Purbeck and the South-West coast of Hampshire. Blandford. W. Ship, Printer and Publisher. 20 pp. By the Rev. John H. Austen, M.A. "The following sketch of the Geology of the S.E. of Dorset has been compiled from notes taken at various periods during three years' residence in the Isle of Purbeck, but which were unavoidably brought to a hasty conclusion, a circumstance which the writer trusts will be a sufficient excuse for any inaccuracies which it may contain. He however anticipates that it will prove to be a sufficient guide to the stranger in this interesting district. Ensbury House, July, 1852. " The most important part with regard to the Purbeck Formation is the log on pages 9 -14 with 129 beds at Durlston Bay listed. The record of fossils and old bed names is useful. Fisher's 1856 log is a modification of this.

Damon, R. 1860. Geology of Weymouth and the Island of Portland with notes on the Natural History of the Coast and Neighbourhood. London. E. Stanford, 220 pp. See also the later edition 1884 - 250 pp. in .

Webster, T. 1815. Correspondence and geological papers of Thomas Webster, 1811-1815. In Special Collections - MS 47, Southampton University Library.

Wilding, R. 1988. Osmond Fisher (1817-1914), Dorset geologist and pioneer geophysicist. Proceedings of the Dorset Natural History and Archaeological Society, 110, 17-22. (See Fisher, 1856, On the Purbeck strata of Dorsetshire). Summary - Osmond Fisher was born in Osmington in 1817. He was interested in geology from a very young age. He graduated in mathematics at Jesus College, Cambridge in 1841, then took holy orders, and in 1845 was appointed Curate-in-charge of the newly rebuilt All Saints' Church, Dorchester, where he stayed for eight years. While at Dorchester he made some useful observations on the geology of Dorset. Later he began to use his mathematical knowledge to solve some geological problems. His book - Physics of the Earth's Crust (1881) was the first textbook of geophysics; in this he anticipated many of the ideas that are now part of plate tectonics theory. For 39 years he was rector of Harlton, near Cambridge, but he returned to Dorset as often as he could to study and write about its geology. He died in 1914 in his 97th year. (he was still publishing whe he was 96! The paper includes a photograph taken in 1898).

Historic Papers

Buckland, W. and De La Beche, 1836. On the geology of the neighbourhood of Weymouth and adjacent parts of the coast of Dorset. Transactions of the Geological Society of London., Series 2, 4, 1-46.

Damon, R. 1860. Geology of Weymouth and the Island of Portland with notes on the Natural History of the Coast and Neighbourhood. London. E. Stanford, 220 pp. See also the later edition 1884 - 250 pp. in .

Englefield, Sir H.C. 1816. A Description of the Principal Picturesque Beauties, etc., of the Isle of Wight. With additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire, by T. Webster. Payne and Foss, London.

Webster, T. 1815. Correspondence and geological papers of Thomas Webster, 1811-1815. In Special Collections - MS 47, Southampton University Library.

Webster, T. 1816. in: Englefield, Sir H.C. 1816. A Description of the Principal Picturesque Beauties, etc., of the Isle of Wight. With additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire, by T. Webster. Payne and Foss, London.

Webster, T. 1826. Observations on the Purbeck and Portland beds. Transactions of the Geological Society of London., 2, 37-44.

Insects

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Bechly , G., Nel, A, Martinez-Delclos, X., Jarzembowski, E. A, Coram, R., Martill, D., Fleck, G., Escuillie, F., Wisshak, M. M. & Maish, M. 2001. A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of numerous new taxa (Insecta: Odonata: Anisoptera). Neue Palaontologische Abhandlungen (Band 4).219 pp.
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Borkent , A. 1995. Biting midges in the Cretaceous amber of North America (Diptera: Ceratopogonidae), Backhuys, Leiden, 237 pp. ISBN 90-73348-40-4. Biting midges extend back to Lower Cretaceous. Purbeck example - Simulidium priscum is wrongly listed as Upper Cretaceous according to review in Palaeontology Newsletter No. 30, Spring, 1996.
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Brodie , P.B. 1845. A History of Fossil Insects in the Secondary Rocks of England accompanied by a particular account of the strata in which they occur, and of the circumstances connected with their preservation. John Van Voorst, London, 130pp.
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Carreck , J.N. 1960. Whitsun field meeting to Weymouth, Abbotsbury and Dorchester, Dorset. Proceedings of the Geologists' Association, London, 71, 341-347.
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Clifford , E., Coram, R., Jarzembowski, E.A. and Ross, A.J. 1994. A supplement to the insect fauna from the Purbeck Group of Dorset. Proceedings of the Dorset Natural History and Archaeological Society, for 1993, 115, 143-146.
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Coram , R.A. and Jarzembowski, E.A. 1999. New fossil flies (Insecta : Diptera) from the Purbeck Limestone Group (Lower Cretaceous, Berriasian) of Dorset, UK. Cretaceous Research, 20, 853-861. Abstract: Two new species from small, exclusively Mesozoic, families of nematoceran Diptera (true flies) from the Purbeck Limestone Group (Berriasian) of Dorset, UK are described, namely Procramptonomyia zigzagensis sp. nov. (Procramptonomyiidae) and Ellia purbeckensis sp. nov. (Elliidae). The fossil evidence suggests that these two families, along with the extant Cramptonomyiidae, are closely related.

Coram, R.A. and Jarzembowski, E.A. (in press). Diversity and ecology of fossil insects in the Dorset Purbeck. In: Symposium, Life and Environments in Purbeck Times, Dorchester, Dorset, 19th-22nd March, 1999. Coram, R. and Jarzembowski, E. A. 1998. Insect-bearing horizons in the type Purbeck and new Purbeck/Wealden flies (Diptera). Proceedings of the Dorset Natural History and Archaeological Society, 119 (for 1997), 135-140.

Coram, R. Jarzembowski, E.A. and Ross, A.J. 1995. New records of Purbeck fossil insects. Proceedings of the Dorset Natural History and Archaeological Society, for 1994, 116, 146-150.

Coram, R, Jarzembowski, E. A & Mostovski, M. B. 2000. Two Rare Eremoneuran Flies (Diptera: Empididae and Opetiidae) from the Purbeck Limestone Group. Paleontological Journal, 34 (Suppl. 3), S370-5373.
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Cornee , A., Dickman, M. and Busson, G. 1992. Laminated cyanobacterial mats in sediments of solar salt works: some sedimentological implications. Sedimentology, 39, 599-612. Use of silver strips for H2S, Chironomid - p. 600, important - salinity controls on gastropod grazing, petees. Chironomids could tolerate up to almost 100 parts per thousand salinity. Purbeck analogue - re Isle of Portland.

Edwards, F.W. 1923. Oligocene mosquitoes in the British Museum. (1 Lower Purbeck specimen). Quarterly Journal of the Geological Society, London. , 79, 139-155.
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Jarzembowski , E.A. 1989. A century plus of fossil insects. Proceedings of the Geologists' Association, London, 100, 433-439.

Jarzembowski, E.A. 1984. Early Cretaceous insects from southern England. Modern Geology, 9, 71-93.

Jarzembowski, E.A. 1987. Early Cretaceous Insects from Southern England. Unpublished Ph.D. Thesis, University of Reading.

Jarzwembowski, E.A. 1991. The Weald Clay of the Weald: report of of 1988/89 field meetings. New insects from the Weald Clay of the Weald. Proceedings of the Geologists' Association, 102, 83-108.

Jarzembowski, E.A. 1991. "Fossil dragonflies", in Prendergast, E.D.V., The Dragonflies of Dorset., pp 59-62, 70-1.

Jarzembowski, E.A. 1993. A provisional checklist of fossil insects from the Purbeck Beds of Dorset. Proceedings of Dorset Natural History Archaeological Society, 114 for 1992. 175-179. . Many are undescribed: about 250 different kinds of beetles are present. 120 species are described; most coleoptera (beetles); many cockroaches, bugs; also lacewings, true flies, dragonflies, grasshoppers and crickets, stick insects, wasps and caddisflies.

Jarzembowski, E.A. 1993. Biting (blood-sucking) insects of the Mesozoic. Palaeontological Association, Abstracts - Christmas Meeting. [Re Jurassic Park - no amberised insects are known from the Jurassic. No mosquitoes known from the Jurassic. The following did evolve in the early Cretaceous (but not in the Jurassic) - black flies, diptera (true flies) including biting midges, sand-flies and horseflies. Fleas known from the Lower Cretaceous but no lice.]

Jarzembowski, E.A. 1995. Early Cretaceous insect faunas and palaeoenvironment. Cretaceous Research, 16, 681-694. [Warmer conditions because of many species of Blattoidea. Lepidoptera were beginning.]

Jarzembowski, E.A. 1996. Towards a revision of Purbeck insects: Protogryllus, Panorpidum, Pleciomyia and Prohousea Nom. Nov. Proceedings of Dorset Natural History Archaeological Society, for 1995, vol 117, 155-157.

Jarzembowski, E.A. 1995. Fossil cadisflies (Insect: Trichoptera) from the early Cretaceous of southern England. Cretaceous Research, 16, 695-704.

Jarzembowski, E.A. and Coram, R. 1997. New fossil insect records from the Purbeck of Dorset and the Wealden of the Weald. Proceedings of Dorset Natural History and Achaeological Society, for 1996, vol.118, 119-124. Authors' Abstract: This paper updates the checklist (Jarzembowski, 1993) and subsequent articles (Clifford et al. 1994; Coram et al. 1995) in previous Proceedings. Recent discoveries are reviewed and Purbeck fossil insects collected by the Revd O. Fisher last century and deposited in the Sedgwick Museum, Cambridge, have been re-examined. Some groups are traced through the non-marine Lower Cretaceous of southern England. (End of Authors' abstract). Bugs, flies etc from the Middle Purbeck of Durlston Bay and dragonfly larvae from the Lower Purbeck of Durlston Bay and Freshwater Bay, Portland.

Jarzembowski, E.A. and Ross, A.J. 1993. Time flies: the geological record of insects. Geology Today, 9, 218-223.

Jarzembowski, E. A, Martinez-Delclos, X., Bechly, G., Nel, A, Coram, R. & Escuillie, F. 1998. The Mesozoic non-calopterygoid Zygoptera: description of new genera and species from the Lower Cretaceous of England and Brazil and their phylogenetic significance (Odonata, Zygoptera, Coenagrionoidea, Hemiphlebioidea, Lestoidea). Cretaceous Research, 19,403-444.
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Lukashevich, E.D., Coram, R.A. and Jarzembowski, E.A. 2001. New true flies (Insecta : Diptera) from the Lower Cretaceous of southern England. Cretaceous Research, 22, 451-460. Abstract: The fossil record of Eoptychopteridae, Ptychopteridae and Dixidae (Insecta; Diptera) is discussed. One new genus and eight new species are described from the English non-marine Lower Cretaceous (Purbeck and Wealden groups): Eoptychoptera longifurcata sp. nov., Eoptychoptera britannica sp. nov., Eoptychopterina demissa sp, nov., Eoptychopterina dimidiata sp. nov., Eoptychopterina camura sp. nov. (Eoptychopteridae), Brodilka mitchelli gen. nov., sp. nov., Zhiganka woolgari sp. nov. (Ptychopteridae) and Eucorethrina westwoodi sp. nov. (Dixidae). Bittacomorphella miocenica (Cockerell, 1910) is transferred to Ptychoptera.
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Martinez-Delclos, X., Nel, A. and Popov, Y.A. 1995. Systematics and functional morphology of Iberonepa romerali n. gen. and sp., Belostomatidae from the Spanish Lower Cretaceous (Insecta, Heteroptera). Journal of Paleontology, 69, (3), 496-508.
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Mostovski , M.B., Jarzembowski, E.A., Coram, R.A. and Ansorge, J. 2000. Curious snipe-flies (Diptera : Rhagionidae) from the Purbeck of Dorset, the Wealden of the Weald and the Lower Cretaceous of Spain and Transbaikalia. Proceedings of the Geologists' Association, 111, 153-160. Abstract: Four new Lower Cretaceous species of the rhagionid genus Ptiolinites are described: Ptiolinites heidiae sp. nov. and P. raypearcei sp. nov. from southern England, P. almulhae sp. nov. from Spain and P. oudatchinae sp. nov. from northern Transbaikalia. Re-evaluation of the antennal structure allows us to assign Ptiolinites to the subfamily Rhagioninae.
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Ponomarenko , A.G., Coram, R.A. and Jarzembowski, E.A. 2005. New beetles (Insecta: Coleoptera) from the Berriasian Purbeck Limestone Group, Dorset, UK. Cretaceous Research, 26, (2) , April 2005, 277-281. By Alexandr G. Ponomarenko, Robert A. Coramb, and Edmund A. Jarzembowskic. Addresses: a. Paleontological Institute, Russian Academy of Sciences, 123 Profsoyuznaya Str., Moscow 117647, Russia; b. 6 Battlemead, Swanage, Dorset BH19 1PH, UK.; c. School of Human and Environmental Sciences, The University, Reading RG6 2AB, UK and Maidstone Museum and Bentlif Art Gallery, St Faith's St, Maidstone, Kent ME14 1LH, UK. Abstract: Four new beetle species are described from the Lower Cretaceous Purbeck Limestone Group of southern England: Mesogyrus anglicus sp. nov. (Gyrinidae), Coptoclavella purbeckensis sp. nov. (Coptoclavidae), Palaeodytes incompleta sp. nov. (Dytiscidae) and Cretorabus sulcatus sp. nov. (Carabidae). The first three taxa were aquatic; the last is terrestrial but may have frequented the margins of water bodies.
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Popov , Y. A., Coram, R. and Jarzembowski, E.A. 1999 (for 1998). Fossil heteropteran bugs from the Purbeck Limestone Group of Dorset. Proceedings of the Dorset Natural History and Archaeological Society, 120, 73-76. Summary: Our current knowledge of the first fossil heteropteran bugs of the basal Cretaceous Purbeck Limestone Group is summarised and several taxa figured for the first time. The fauna is compared with others of similar age worldwide. End of Summary. - Notes: These are mostly aquatic or semi-aquatic bugs with piercing and sucking mouth-parts. Giant water bugs of the extant predatory family Belostomatidae are known from the Middle Purbecks of Durlston Bay. Aquatic bugs do not occur in some parts of the Soft Cockle Member because of unfavourable hypersaline conditions, and here fragments of terrestrial forms predominate.
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Rasnitsyn , A.P., Jarzembowski, E.A. and Ross, A.J. 1998. Wasps (Insecta: Vespida=Hymenoptera) from the Purbeck and Wealden (Lower Cretaceous) of southern England and their biostratigraphical and palaeoenvironmental significance. Cretaceous Research, 19, 329-391. Abstract with faunal list section omitted: This is the first comprehensive study of the insectan order Vespida (Hymenoptera) in the English non-marine Lower Cretaceous (Purbeck and Wealden strata). The fauna includes various diverse sawflies, parasitoid and aculeate wasps but with the exception of social groups. The stratigraphical occurrence and fossiliferous localities are reviewed by AJR. The wasps are revised, described, and keyed out by APR and EAJ who erect 10 new genera and 35 new species: Undatoma stigmatica sp. nov, U. rudwickensis sp. nov. ............. Iwestia provecta gen. et sp. nov. (Sphecidae)... (... continues ...) The Purbeck fauna is more diverse generically and contains a greater number of endemics than the Wealden fauna. The absence of xyelids from the Purbeck and Wealden is consistent with a warm climate. Late Mesozoic vespidan faunas are compared globally (especially with eastern Asia), and four Jurassic-Cretaceous assemblages are recognised: an ephialtitid-praeaulacine or aculeate-free Jurassic type; a Lower Cretaceous baissine type with earlier proctotrupid and later angarospecine subtypes: an Upper Cretaceous armaniid type. The Purbeck-Wealden fauna is baissine with two Jurassic "survivors" but lacks social groups; both assemblage subtypes are represented but the influx of aculeate wasps is accompanied by reduced endemicity and generic diversity possibly indicative of ecological change in the hinterland.

Scudder, S.H. 1886. A review of Mesozoic cockroaches. Memoirs of Boston Society for Natural History, 3, 439-485, pls 46-8.

Walker, I.R., Wilson, S.E. and Smol, J.P. 1995. Chironomidae (diptera) - quantitative paleosalinity indicators for lakes of western Canada Canadian Journal of Fisheries and Aquatic Sciences. 52, 5, 950-960. (Purbeck analogue)

Westwood, J.O. 1854. Contributions to fossil entomology. Quarterly Journal of the Geological Society of London, 10, 378-396, pls 14-18.

Whalley, P.E.S. and Jarzembowski, E.A. 1985. Fossil insects from the lithographic limestone of Montsech (early Cretaceous), Lerida Province, Spain. Bulletin of the British Museum, Natural History (Geol.), 38, 381-412.

Zeuner, F.E. 1939. Fossil Orthoptera Ensifera, xiii + 321 pp., 80 pls.

Zeuner, F.E. 1942. Localities and preservation of fossil insects. Proceedings of the Geologists' Association, 53, 108-111.

Isopods

Andrews, and Jukes-Browne, 1894. Quarterly Journal of the Geological Society, London, vol. 1, p.52 -

Arkell , W.J. 1947. The Geology of the Country around Weymouth, Swanage, Corfe and Lulworth. Memoir of the Geological Survey, 386 pp.

Bristow, H.W. and Forbes, E. 1884. Sections of the Purbeck strata of Durlston Bay, Dorset. Pp 201-209 in Damon ,R.F., Geology of Weymouth, Portland and the Coast of Dorsetshire from Swanage to Bridport-on- the-Sea: with Natural History and Archaeological Notes. 2nd ed., R.F.Damon, Weymouth, 250 pp.

Brodie, P.B. 1845 A History of Fossil Insects in the Secondary Rocks of England. accompanied by a particular account of the strata in which they occur, and of the circumstances connected with their preservation. John Van Voorst, London, 130pp.

Fisher, O. 1856. On the Purbeck strata of Dorsetshire. Transactions Cambridge Philosophic Society, 9, 555-581.

Gray, J. 1988. Evolution of the freshwater ecosystem: the fossil record. Palaeogeography, Palaeoclimatology, Palaeoecology, Special Issue, Aspects of Freshwater Paleoecology and Biogeography (Gray, J. editor), 62, 1-214

Harland, W.B. et al. 1967. The Fossil Record: A Symposium with Documentation. Geological Society of London, London, 827p.

Martini, E. 1972. The genus Eosphaeroma (Isopoda ) in the European Paleogene (in German: Die Gattung Eosphaeroma ( Isopoda ) im eropaischen Alttertiar). Senckenhergiana lethaea, 53, 65 -79. ( redescribed two isopod species from the Bembridge Marls of Gurnard Bay, Isle of Wight - lower Oligocene - lagoonal - see Daley papers for palaeoenvironments) (Purbeck isopod analogue)

Milne-Edwards, H. 1843. Note sur deux Crustaces fossiles de l'Ordre des Isopodes. (Archaeoniscus Brodiei) . Ann. of Science Naturelles, ser. 2, vol 20, p. 323 see also Idem 1844 vol 18, p.110

Moore, R.C. 1969 Treatise on Invertebrate Paleontology, Part R, Arthropoda 4. vol. 1 ,398pp. (Isopods - Purbeck Archaeoniscus)

Reid, C. 1903. The Geology of the Country around Salisbury (explanation of sheet 298), Memoirs of the Geological Survey, H.M. Stationery Office , London, 77pp. (Vale of Wardour Purbeck)

Strahan, A. 1898. The Geology of the Isle of Purbeck and Weymouth. Memoirs of the Geological Survey, England and Wales. 278pp.

Woodward, H. 1879. On Branchipus......... ............, Eocene Gurnet Bay, Isle of Wight . Quarterly Journal of the Geological Society, 35, 342 -350. (with description of Archaeoniscus brodiei).

Woodward, H.B.1895. The Jurassic Rocks of Britain. Vol 5. The Middle and Upper Oolitic Rocks of England (Yorkshire excepted). Memoirs of the Geological Survey of the United Kingdom. 499pp. and

Isotopes

See Geochemistry Isotopes

Isopachytes (Isopachs)

(see Thickness)

West, I.M., 1992. Contribution on Purbeck Formation in: Cope, J.C.W., Ingham, J.K. and Rawson, P.F. (editor). 1992. Atlas of Palaeogeography and Lithofacies. Geological Society of London.

Jura Mountains of Switzerland and France

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Carozzi, A. 1948. Etude Stratigraphique et Micrographique du Purbeckien du Jura Suisse. Faculte des Sciences, Universite de Geneve, 175 pp. Stratigraphic and Micrographic Study of the Purbeckian of the Swiss Jura. Thesis presented at the Faculty of Sciences at Geneva University for degree of Doctor of Science in Geology and Mineralogy. Thesis No. 1122. This work is in printed and published paperback book format. [This is a classic, early, petrographic study of the Purbeck Formation, with quantitative data. Extract (which I have translated from the French): "The Purbeckian of the Swiss Jura presents two palaeogeographic domains that are quite distinct, already in part delimited by Maillard. The most extensive is the domain of the Lower Dolomitic Beds which covers the Vaudois Jura and the southern part of the Neuchatelois Jura and the Jura Bernois Jura. From the bottom to top there are 1. The Lower Dolomitic Beds (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), and 3. Upper Brackish or Upper Marine (Upper Purbeck)...
To the north of this zone in the heart of the Neuchatelois Jura is the domain of the marls with gypsum. The type succession is from bottom to top: 1. Marls with Gypsum (Lower Purbeck), 2. Lacustrine Beds (Middle Purbeck), Upper Brackish or Marine Beds (Upper Purbeck)."
[A variety of interesting Purbeck topics are discussed including the Black Pebbles, the multicoloured breccio-conglomerates, the source of Mg, the charophytes, ostracods, the grumeleux limestones (also common in Dorset), the dolomites (cf. the Lower Purbeck dolomitic marls of Dorset), pelletoidal limestones ("pseudo-ooliths"), microbreccias, cargneules, celestite, gastropods, Dasycladiaceans (not present in Dorset), cylces of sedimentation, and faecal pellets. It has many graphic logs and maps and a good bibliography of the older Purbeck literature, much of which is not listed here. An important aspect is that Carozzi related Purbeck facies to palaeotectonics, with the dolomite facies of the Lower Purbeck girdling the gypsum facies which mostly occurs on the structural highs. The Dorset Purbeck is also, of course, affected by palaeotectonics - the well-known, Late Kimmerian. However, thickness variations are rather most noticeable in Dorset than the facies variations. Carozzi does not discuss the Dorset succession, but his work is useful for comparative purposes. Carozzi's thesis is an old classic and recommended reading for Dorset Purbeck enthusiasts.]
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Deconinck , J.F. and Strasser, A. 1987. Sedimentology, clay mineralogy and depositional environment of Purbeckian green marls (Swiss and French Jura). Eclogae geol. Helv., 80, 753-772. Abstract: Purbeckian green marls in the Swiss and French Jura usually occur at the top of small-scale shallowing upward sequences which commonly end with evidence of subaerial exposure. Clay mineralogical assemblages are mainly composed of illite and detrital Al-Fe smectite in the northwestern parts of the study area, and almost entirely of illite in the southeast. This geographical distribution originates (a) from detrital input caused by the erosion of smectite-rich soils which developed in downstream continental areas under hot and seasonally humid climates, (b) from transitions of Al-Fe smectite to Fe-illite determined by cyclic wetting by marine waters and drying. These results are in agreement with mixed marine and freshwater fossils found in the green marls, and with their sedimentological context. (Palygorskite is also present)

Deconinck, J.F., Strasser, A. and Debrabant, P. 1988. Formation of illitic minerals at surface temperatures in Purbeckian sediments (Lower Berriasian, Swiss and French Jura). Clay Minerals, 23. 91-103. Abstract: The clay-mineralogical assemblage of Purbeckian carbonate sediments of the Swiss and French Jura Mountains are often composed of illite and interstratified illite-smectite. These illitic minerals occur mainly in thin layers of green marls which show evidence of subaerial exposure and mark the top of the shallowing upward sequences. X-ray diffraction, chemical and thermal analyses coupled with transmission electron microscopy suggest that the Purbeckian illitic minerals replaced smectite in intermediate continental-marine environments. The transition from smectite to illite and interstratified illite-smectite probably resulted from repeated cycles of wetting by marine waters and subsequent drying in hypersaline environments, under a hot Purbeckian climate.

Persoz, F. and Remane, J. 1976. Mineralogie et geochemie des formations a la limite Jurassique-Cretace dans le Jura et le Bassin vocontien. Eclogae Geol. Helv., 69/1, 1-38. (Palygorskite found in Purbeck facies).
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Strasser, A. 1986. Ooids in Purbeck limestones (lowermost Cretaceous) of the Swiss and French Jura. Sedimentology, 35, 711-727.

Strasser, A. 1988. Shallowing-upward sequences in Purbeckian peritidal carbonates (lowermost Cretaceous, Swiss and French Jura Mountains). Sedimentology, 35, 369-383.

Lake Analogues

Anadon, P. Cabrera, L. and Kelts, K. 1991. Lacustrine Facies Analysis. I.A.S. Special Publication No. 13, Blackwell Scientific Publications, Oxford, Includes Platt, N.H. and Wright, V.P. 1991. Lacustrine carbonate facies models, facies distributions and hydrocarbon aspects. Pp. 57-74. Two papers on the Spanish Wealden - carbonate and coal deposition and on rhythmically laminated lacustrine carbonates.

Coulter, G.W. (ed.) 1991. Lake Tanganyika and its Life. With contributions by J-J. Tiercelin, A. Mondegeur, R. Hecky and R. Spigel. March 1991, 352p. Natural History Museum, London. co-published with OUP. Lake Tanganyika is the largest in volume of the African Lakes and is the second deepest lake in the world. The aquatic flora and fauna are remarkable for their diversity and high degree of endemicity, as well as for the number of species and genera present. Collates scientific knowledge. Comprehensive bibliography.

Gierlowski-Kordesch, E., Gomez Fernandez and Melendez, N. 1991. Carbonate and coal deposition in an alluvial-lacustrine setting: Lower Cretaceous (Weald) in the Iberian Range (east-central Spain). Pp. 109-128 in: Anadon, P. Cabrera, L. and Kelts, K. 1991. Lacustrine Facies Analysis. I.A.S. Special Publication No. 13, Blackwell Scientific Publications, Oxford,

Gomez Fernandez, J.C. and Melendez, N. 1991. Rhymically laminated carbonates in the Lower Cretaceous of La Serrania de Cuenca Basin (Iberian Ranges, Spain). Pp 245-256 in: Anadon, P. Cabrera, L. and Kelts, K. 1991. Lacustrine Facies Analysis. I.A.S. Special Publication No. 13, Blackwell Scientific Publications, Oxford, Upper Hauterivian? to Lower Barremian. Central eastern Spain. Lacustrine varves, fish. Thermally stratified lake with anoxic bottom. Weathering, marmorisation. Palustrine. Brecciated tops of limestone. Miliolids, foraminifera.

Platt, N.H. and Wright, V.P. 1991. Lacustrine carbonate facies models, facies distributions and hydrocarbon aspects. Pp. 57-74. in Anadon, P. Cabrera, L. and Kelts, K. 1991. Lacustrine Facies Analysis. I.A.S. Special Publication No. 13, Blackwell Scientific Publications, Oxford.

Lithostratigraphy

Westhead, R.K. and Mather, A.E. 1996. An updated lithostratigraphy for the Purbeck Limestone Group in the Dorset type-area. Proceedings of the Geologists' Association, 107, 117-128. Not very detailed compared with the traditional scheme of members. Probably useful for mapping.

Lizards

Ensom, P.C. 1988. Excavations at Sunnydown Farm, Langton Matravers, Dorset: Amphibians discovered in the Purbeck Limestone Formation. Proceedings of Dorset Natural History Archaeological Society, 109, 148-150. Sauropod footprints, salamanders, multituberculate mammals. Iguanodon footprints. Cherty Freshwater Member. Also see paper in Palaeontology giving full description of mammals.

Ensom, P.C., Evans, S.E. and Milner, A.R. 1991. Amphibians and reptiles from the Purbeck Limestone Formation (Upper Jurassic) of Dorset. Fifth Symposium on Mesozoic Terrestrial Ecosystems and Biota. Extended Abstracts - edited by Zofia Kielan-Jaworowska, Natascha Heintz and Hans Arne Nakrem. Contributions from the Paleontological Museum, University of Oslo, No. 364, 1991. Pp 19-20. Enigmatic lizard Durotrigia.

Evans, S.E. 1994. A new anguimorph lizard from the Jurassic and Lower Cretaceous of England. Palaeontology, 37, 33-49. Parviraptor, Purbeck, Beckles.

Hoffstetter, R. 1967. Coup d'oeil sur les sauriens (= Lacertiliens) des couches de Purbeck (Jurassique superieur d'Angleterre). Colloques Internationaux du C.N.R.S., 163, 349-371. The enimatic lizard Durotrigia. Now also known from Sunnydown Farm (Ensom et al., 1991).

Mansel-Pleydell, J.C. 1888. Fossil reptiles of Dorset. Proceedings of the Dorset Natural History and Antiquarian Field Club , 9, 1-40.

Magnetostratigraphy, Geomagnetic Reversals, Palaeomagnetism etc.

Allen, P. and Wimbledon, W.A. 1991. Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas. Cretaceous Research, 12, 511-526. Some magnetostratigraphy - reversals CM 18 - CM in Pb.
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Ogg , J.G., Hasenyager, R.W., Wimbledon, W.A., Channel, J.E.T. and Bralower, T.J. 1991. Magnetostratigraphy of the Jurassic-Cretaceous boundary interval - Tethyan and English faunal realms. Cretaceous Research, 12, 455-482. Abstract: Geomagnetic reversals and magnetic polarity chrons provide an important chronostratigraphic tool for global correlation. An integrated Tithonian-Berriasian biostratigraphic and magnetic polarity time scale for the Tethyan faunal realm for the Tithonian and Berriasian stage is compiled from 17 independent biomagnetostratigraphic sections. This time scale incorporates zones and first/last appearance datums form ammonites, calpionellids, calcareous nannofossils and dinoflagellates. The database provides an estimate of the range of observed appearance datums or zonal boundaries relative to polarity chrons; such apparent "diachoniety" probably results from a combination of preservation of species and paleontological methodology, rather than migration. The lithologic transition from "Rosso Ammonitico" red marly limestone to "Maiolica" white limestone occurs at different times during the Tithonian among the various sections, ranging from polarity zone M22n (mid-Early Tithonian) in some Spanish "slope" and Italian basinal-facies sections, ranging from polarity zone M19n (mid-Late Tithonian) in the central Atlantic and some plateau-facies Italian sections. This widespread lithological change is, therefore, probably a result of shifting local patterns of fertility overprinted on the main regional trend. Magnetostratigraphy from the Purbeck Limestone Formation in the English Boreal faunal realm was obtained from the "classic" section at Durlston Bay in Dorset. The Dorset section displays predominantly normal polarity with a minimum of three reversed-polarity zones, but distortion of the magnetic polarity record by variable rates of sedimentation in this marginal clastic environment coupled with lack of independent correlation methods currently precludes a unique correlation to the Tithonian-Berriasian magnetic polarity time scale. The Tithonian-Berriasian magnetic polarity time scale may eventually provide a global chronostratigraphic definition of the Jurassic-Cretaceous boundary. End of Abstract....[Notes re Purbeck of Dorset: Durlston Bay section. Predominantly normal polarity with three reversed polarity zones but distortion of pattern by variable sedimentation rates coupled with lack of independent methods precludes unique correlation to Tithonian-Berriasian magnetic polarity time scale. M 18r to M 15 r. Keywords: ammonites, Atlantic, Bay, Berriasian, Boreal, calpionellids, chron, correlation, Cretaceous, dinoflagellates, Durlston, geomagnetic, geomagnetism, magnetic, magnetostratigraphy, M-sequence, nannofossils, palaeomagnetism, paleomagnetism, polarity, reversal, Purbeck, stratigraphy, Tithonian, zone]

Go to Mammals in Purbeck Vertebrate Bibliography.

Mammal Bed

Go to Mammal Bed in Purbeck Vertebrate Bibliography.

Maps

Anderson, Tom, 1962. Purbeck: A part of the Coast from Kimmeridge to Anvil Point. Wm. Jeremiah Bower, Toponymist. Printed in Cambridge 1962. . A map showing cliff features. Available from the Lifeboat shop in Swanage at £1.50 in 1993. Fishermans Ledge of West 1975 and the earlier climbing books is Cunner Cove (Cunner is local name for a wrasse. This is according to Treleven Haysom, personal communication, 1993). Note the Cunner not Conner spelling.

Cosgrove, M.E. and Hearn, E.W. 1966. Structures in the Upper Purbeck Beds at Peveril Point, Swanage, Dorset. Geological Magazine, 103, No.6, 498-507. Bulge structure.

House, M.R. 1961. The structure of the Weymouth Anticline. Proceedings of the Geologists' Association, 72, 221-238. .

Nunn, J.F. 1992. A geological map of the Purbeck Beds in the northern part of Durlston Bay. Proceedings of Dorset Natural History Archaeological Society, 113, 145-148. Two photographs (Figs. 2a, 2b) of the southern Peveril Anticline are shown at a time when it was well-exposed because of a storm. It is was concealed by 1993.

Marble, Purbeck Marble

Drury, G.D. 1948. The use of Purbeck Marble in Mediaeval times. Proceedings of Dorset Natural History Archaeological Society, 70, 74-98. . (Medieval). Fonts, Churches, Romsey Abbey. Spectacular boom in the 13 Century. Decline after the middle of the 14 Century. Rivals - Bethersden Kent and Petworth Sussex. Later replaced by alabaster for carving. Still some use even in 16 Century.

Legg, R. 1989. Purbeck Island: the industrial, social and natural history of a corner of England. 2nd revised edition (first published 1972). Dorset Publishing Company at the Wincanton Press, Wincanton, Somerset, 230. ISBN 0 948699 08 6. (Chapter 2 - An Age of Marble, pp 9-18. Upper Purbeck Viviparus limestone, not a true marble but it is strong and takes a polish, was extensively quarried in very shallow quarries westward from Swanage. Effigies - Abbot Clement who died in 1163, Leofric , effigies at Salisbury Cathedral 1186; polished shafts in Gothic churches; King Henry III obtained marble for Westminster Abbey. Several thousand coffin lids of Purbeck marble. Other uses discussed. Eventually replaced by alabaster. Legg notes that the red marble in the east was preferred to blue marble.

Warren, F.C. 1951. Dorset livelihoods. Dorset Year Book 1951-52. pp. 133- 145.

Megapolygons

Andrews, J.E. 1988. Soil-zone microfabrics in calcrete and in desiccation cracks from the Upper Jurassic Purbeck Formation of Dorset. Geological Journal, 23, 261-270. Alveolar septal structure, needle fibre, desiccation cracks, calcrete.

Pugh, M.E. 1968. Algae from the Lower Purbeck limestones of Dorset. Proceedings of Geologists' Association, London, 79, 513-523.

Megapolygons Analogue

Ferguson, J., Burne, R.V. and Chambers, L.A. 1982. Lithification of peritidal carbonates by continental brines at Fisherman Bay, South Australia, to form a megapolygon/spelean limestone association. Journal of Sedimentology Petrology, 52, 1127-1147.

Ferguson, J. Chambers, L.A., Donnelly, T.H. and Burne, R.V. 1988. Carbon and isotope composition of a recent megapolygon-spelean limestone, Fisherman's Bay, South Australia. Chemical Geology, 72, 63-76.

Microplankton

Hunt, C.O. 1987. Dinoflagellate cyst and acritarch assemblages in shallow-marine and marginal-marine carbonates: the Portland Sand, Portland Stone, and Purbeck Formations (Upper Jurassic/Lower Cretaceous) of southern England and northern France. In: Micropalaeontology of Carbonate Environments (ed. Hart, M.B.), pp. 208-225, Ellis Horwood, Chichester. Hunt placed the Jurassic/Cretaceous boundary just above the base of the "Cypris " Freestones, on the basis of palynomorphs. This is supported by Feist et al. 1995).

Molluscs - General

Arkell, W.J. 1947. The Geology of the Country around Weymouth, Swanage, Corfe and Lulworth. Memoir of the Geological Survey, 386 pp. Various gastropods and bivalves figured.

Casey, R. 1955. The pelecypod family Corbiculidae in the Mesozoic of Europe and the Near East. Journal of Washington Academy Science., 45, 366-372. .

Casey, R. 1955. The Neomiodontidae, a new family of the Arcticacea (Pelecypoda). Proceedings of the Malacological Society, 208-222.

Damon ,R.F., 1884 Geology of Weymouth, Portland and the Coast of Dorsetshire from Swanage to Bridport-on- the-Sea: with Natural History and Archaeological Notes. 2nd ed., R.F.Damon, Weymouth, 250 pp.

Morter, A.A. 1984. Purbeck - Wealden Beds, Mollusca and their relationship to ostracod biostratigraphy, stratigraphical correlation and palaeoecology in the Weald and adjacent areas. Proceedings of the Geologists' Association, London, 95, 217-234.

Radley, J. 198? Purbeck and Portland Gastropods. M.Sc. Thesis. Extracts in . Full title not known. True low salinity gastropod faunas in veirtual evolutionary stasis since their appearance in the Jurassic. Much Buckinghamshire information in thesis although only small amount in this extract. Aptixiella portlandica - occurrence and mode of life. Micromorphic gastropod faunas of "algal meadows". Valvata, Hydrobia, Natica, Bathrotomaria Aylesbury, Creamy Limestones Chilmark Tisbury Ragstones Shotover.

West, I.M., Ali, Y.A. and Hilmy, M.A. 1986. Facies associated with primary gypsum nodues of the northern Egyptian sabkhas. Pp. 171-183 in: Sixth International Symposium on Salt, 1983, vol. 1. Published by the Salt Institute, 206 North Washington Street, Alexandria, Virginia, 22324, USA. (Discusses analogy between dwarfed Cardium glaucum in hypersaline Egyptian coastal lagoons and the small Protocardia purbeckensis, the Purbeck "cockle" of hypersaline parts of the Lower Purbeck Formation of Dorset.)

Mudslide Chutes, Penecontemporaneous Mudflows Etc.

West, I.M. 1993. Purbeck Field Notes. 21 st October 1993. A mudslide chute 2 m long and 10cm wide at maximum was seen on the surface of bed 133, just north of Door Bay. It shows movement starting in direction 40 degrees, but curving slightly eastward. The bed contains Praeexogyra. Many years ago an example found in a block on the beach was photographed. There is a Journal of Sedimentary Petrology photograph showing a similar feature in modern sediment. A copy is in the Purbeck field notes file.

Neomorphism (Pseudopleochroic Calcite Etc)

Maliva R. G. and Dickson J. A. D. 1992. The mechanism of skeletal aragonite neomorphism: evidence from neomorphised mollusks from the Upper Purbeck Formation (Late Jurassic-Early Cretaceous), southern England. Sedimentary Geology, p. 221.

Nomenclature, Stratigraphic

Westhead, R.K. 1992. Geology of the Dorchester (South) District (Dorset). 1:10,000 Sheet SY NE. British Geological Survey Technical Report WA/93/22. (Also includes part of 1:50,000 Sheet 328 Dorchester, 327 Bridport and 341/342 Weymouth). . Not in (Sept 93). Mapping by Westhead. Logging of Purbeck Group pits was undertaken by A.E. Mather (Plymouth University), who also provided sedimentological information. Purbeck succession divided into (from base) Windsbatch Limestone Mb, Bincombe Mb, Ridgeway Mb, Bayard Hill Limestone Mb and at top Friar Waddon Member. Named chalk subdivisions for the Dorchester area are given. This is simplistic with regard to the Purbeck Formation and units are simply listed as "micrite" and shown without detailed description except where Ensom's work is used.

Oil-Shale

Milner, H.B. 1922. The Geology of the Country around Heathfield, Sussex. Proceedings of Geologists' Association, 33, p. 142 - . Oil shale in the Purbecks.

Oolites in the Purbeck Strata
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Strasser , A. 1986. Ooids in Purbeck limestones (lowermost Cretaceous) of the Swiss and French Jura. Sedimentology, 35, 711-727.
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West, I.M., 1964. Evaporite diagenesis in the Lower Purbeck Beds of Dorset. Proceedings of the Yorkshire Geological Society, 34, 315-330.

West, I.M., 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, 86, 205-225.

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium - Sedimentation Jurassique W. Europeen. A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

Ostracods
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Anderson , F.W. - Purbeck ostracod specialist - see orbituary in Annual Report of the Geological Society, London, 1982. [Appointed assistant lecturer in Geology and Zoology at Southampton University College in 1928. Later Lieutenant Colonel in the Second World War and then Chief Palaeontologist at the Geological Survey. He wrote many papers on ostracods and other topics; only some are listed here.]

Anderson, F.W. 1932. Phasal deposition in the Middle Purbeck Beds of Dorset. Report of the British Association for the Advancement of Science for 1931, 379-380. [Early report of cyclicity in the Purbecks as shown by ostracod faunas. The start of F.W. Anderson's work.]

Anderson, F.W. 1941. Ostracoda from the Portland and Purbeck Beds at Swindon. Proceedings of the Geologists' Association, 51, 373-384.

Anderson, F.W. 1958. In: Wilson, V., Welch, F. B. A., Robbie, J.A. and Green, G.W. 1958. Geology of the Country around Bridport and Yeovil. Memoir of the Geological Survey of Great Britain, Explanation of sheets 327 and 312. 118-129. Purbeck ostracod zones given for the Purbeck outcrops in the east of the area.

Anderson, F.W. 1973. The Jurassic-Cretaceous transition: The non-marine ostracod faunas. In: R.Casey and P.F.Rawson (Eds.) The Boreal Lower Cretaceous. Seel House Press, Liverpool, Special Issue of the Geological Journal, 5, 101-110.

Anderson, F.W. l985. Ostracod faunas in the Purbeck and Wealden of England. Journal of Micropaleontology, 4, pp.l-68. Abstract: The occurrence and abundance of ostracods found in 98 subdivisions (Faunicycles) of late Jurassic to early Cretaceous age in the English Purbeck and Wealden are summarised. Most of the taxa found are illustrated from holotype or other material and details of their ranges and abundance given in relation to each faunicycle. The characters of the ostracod assemblages and zones are decribed. Three new species (Cypriea brendae, C. hispida and Eoparacypris edmundsi) ; also two new subspecies (Cypridea setina pelota and C. tuberculata dorsiclavata) are described and figured. A lectotype for Palaeocytheridea pellucida is selected and figured.

Anderson, F.W. and Barker, D. 1966. Some British Jurassic and Cretaceous ostracoda. Bulletin of the British Museum (Natural History), Geology, Vol. 11, No. 9, London. Pp. 433-487; 9 Plates; 32 Text-figures. Comprises: 1. Anderson - New Genera of Purbeck and Wealden Ostracoda. 2. Barker - Ostracods from the Portland Beds of Dorset. 3. Barker - Ostracods from the Portland and Purbeck Beds of the Aylesbury District.

Anderson, F.W. and Bazley, R.A.B. 1971. The Purbeck Beds of the Weald (England). Bulletin of the Geological Survey, U.K. 34, 1-173.

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Barker , D. 1966a. Ostracods from the Portland Beds of Dorset. Bulletin of the British Museum (Natural History), Geology, 11, 447-457, pls. 1-6.

Barker, D. 1966b. Ostracods from the Portand and Purbeck Beds of the Aylesbury District. Bulletin of the British Museum (Natural History), Geology, 11, 459-487, pls. 7-9.

Barker, D., Brown, C.E., Bugg, S.C. and Costin, J. 1975. Ostracods, land plants and charales of the basal Purbeck Beds of Portesham Quarry. Palaeontology, 18, 419-436.
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Bate , R.H. and Robinson, E. 1978. A Stratigraphical Index of British Ostracoda. edited by Raymond H. Bate and Eric Robinson.

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Brown, P.R. 1963. Algal limestones and associated sediments in the basal Purbeck of Dorset. Geological Magazine, 100, 565-573.
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Clements, R.C. 1969. Contribution to the section on the Purbeck Beds. In:H.S.Torrens (Ed.) Guide for Dorset and South Somerset. Int. Field Symposium on the British Jurassic.

Clements, R.G. 1993. Type-section of the Purbeck Limestone Group, Durlston Bay, Swanage, Dorset. Proceedings of Dorset Natural History Archaeological Society, 114 for 1992, 181-206. [Classic section log , ostracod data].
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Colin, J.-P. and Oertli, H.J. 1985. Purbeckien. In: Atlas des Ostracodes de France (ed. Oertli, H.J.), Bulletin des Centres de Recherches Exploration-Production Elf-Aquitaine, Memoire 9, 148-161.
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Grekoff, N. 1953. Sur l'utilisation des microfaunes d'ostracodes dans la stratigraphique precise du passage Jurassique-Cretace (facies continentaux). Extrait de la Revue de l'Institut Franc du Petrole et Annales des Combustibles Liquides, , p. 362- .
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Horne, D.J. 1988. Cretaceous ostracoda of the Weald. British Micropalaeontological Society Field Guide, 4, 42pp.

Horne, D.J. 1995. A revised ostracod biostratigraphy for the Purbeck-Wealden of England. Cretaceous Research, 16, 639-663, Academic Press Ltd. Abstract: The extensive work of the late F.W.Anderson on Purbeck-Wealden ostracods is critically reviewed. He used ostracods as the basis of four different kinds of stratigraphical subdivision in the English Purbeck-Wealden sequence: zones (based on the ranges of Cypridea species), faunicycles (based on alternations of assemblages dominated by Cypridea with assemblages dominated by other genera), 'beds' and 'assemblages' (both groupings of faunicycles). It is concluded that although Anderson's own correlations using these schemes might be regarded as reliable, all of them were so poorly defined as to preclude their use by future workers. Furthermore, erroneous zonation schemes have been propagated by other authors who mistook Anderson's assemblages for zones. In spite of criticisms of his applications and interpretations of ostracods, Anderson's data remain the best available for the Purbeck-Wealden of the Weald and Wessex sub-basins. As a solution to some of these problems, a new ostracod biozonation scheme is proposed, comprising three zones (Theriosynoecum forbesi Zone, approximately equal to the Purbeck; Theriosynoecum alleni Zone, approximately equal to the Hastings Beds Group; Theriosynoecum fittoni Zone, approximately equal to the Weald Clay Group), subdivided into eight subzones on the basis of the ranges of Cypridea species. [end of abstract] [Comments by Ian West: A very good paper with amongst other topics (which includes important zonal schemes), a sensible and realistic assessment of F.W. Anderson's ostracod work and his faunicycles. Many Purbeck workers have probably found these "cycles" potentially valuable but difficult to use in practice. Anderson in (1932) started his studies of ostracods and cyclicity in the Middle Purbeck Beds of Durlston Bay. Later he worked extensively with boreholes. For those involved with Durlston Bay it has been difficult to fix his faunicycles well, because of lack of precise ostracod sample data. Anderson's basal Purbeck work in Dorset was sketchy, largely because of hypersaline facies and lack of low salinity ostracods. It does not tie in with detailed petrographic studies of these beds (West, 1975). Amongst other things, this recent paper by Horne with its reassessment of Anderson's work much facilitates the understanding of the faunicycles.]
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Jones , T.R. 1878. Notes on some fossil bivalved Entomostraca: iv. Geological Magazine, (2), vol. 5, 103-110, 277-278. [Purbeck and Wealden ostracods.]

Jones, T.R. 1885. On the ostracoda of the Purbeck Formation. Quarterly Journal of the Geological Society, 61, 311-353.

Jones, T.R. 1890. On some fossil Estheriae: B. Purbeck Estheriae. Geological Magazine, vol. 7, 385-390. [Uestheria]
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Kilenyi, T.I. and Neale, J.W. 1978. The Purbeck/Wealden. In: A Stratigraphic Index of British Ostracoda. (Eds. Bate, R.H. and Robinson, J.E.), Geological Journal, Special Issue, 8, 299-324.
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Martin, G.P.R. 1958. Uber die systematische sellong der gattung Cypridea Bosquet (Ostracoda) nebst Beschreitung der Wealdn-basis Ostracode C. buxtorfi n. sp. Neues Jahrb. Geol. Palaeontol. Monatsh. 7, 312, 320. Stuttgart.

Martin, G.P.R. und Weiler, W. 1954. Fisch-Otolithen aus dem deutschen Mesozoikum (Dogger bis Wealden). Senckenbergiana Lethaea, Bd. 35, no. 3/4, 119 -192. Frankfurt.
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Oertli , H.J. 1963. Ostracodes du "Purbeckien" du Bassin Parisien. Revue de L'Institut Francais du Petrole , 18, No. 1, January, 1963. Paris. Abstract: The analysis of cuttings from some 12 oil drillings in the Aisne department (between Reims and Paris) lead to identification of some 20 species of Ostracoda (of which I new subspecies and several unknown forms) which all belong to the lower Purbeckian stage (English classification). The middle and upper Purbeckian stages do not seem to be present and the Valanginian-Wealdian stage, if it is represented, has left no trace of microfauna. Deposits between the Purbeckian and middle Kimmeridgian (after Arkell) are present under lagoonal facies (several local zones are suggested); this accounts for the fact that these stages also are commonly named "Purbeckian" in petroleum geology. [With 7 plates containing good photographs of ostracods. 57 species are shown, including Cypridea dunkeri Jones, for example. This is well-known from the (relatively unusual) Lower Purbeck freshwater facies of Swindon and Portesham in England. It is typical of the lower part of the Lower Purbeck. Also "Cypris" purbeckensis etc. Fig. 6 is a correlation chart relating the French borehole "Purbeckien" to Upper Kimmeridgian to Lower Purbeck of Dorset, and to the Eimbechauser Schichten, the Munder Mergel and the Serpulite of northwest Germany.]
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Rosenfeld, A., Gerry, E. and Honigstein, A. 1988. Jurassic-Cretaceous non- marine ostracods from Israel and palaeoenvironmental implications. Pp.659- 669 in Hanai, T., Ikeya, N. and Ishizaki, K. (Eds.) Evolutionary Biology of Ostracoda: Its Fundamentals and Applications. Developments in Palaeontology and Stratigraphy, Elsevier.
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Sylvester-Bradley , P.C. 1949. The ostracod genus Cypridea and the zones of the upper and middle Purbeckian. Proceedings of the Geologists' Association, London, 60, 125-151.
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Sztejn , J. 1991. Ostracods from the Purbeckian of central Poland. Acta Palaeontologica Polonica, 36, 115-142.
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Wakefield, M.I. 1995. Ostracod biostratinomy at lagoonal shorelines: examples from the Great Estuarine Group, Middle Jurassic, Scotland. Proceedings of the Geologists' Association, 106, 211-218. [Not on Purbeck ostracods but there some similarity to Purbeck ones. Darwinula develops during warmer months; Spring assemblages with older instars but without very young ones can be recognised. Darwinula lives 3 to 4 years. Cup-in-cup ostracods in Purbeck. Indicative of deposition at or just below the water's edge.]
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Whatley, R.C. 1988. Population studies of ostracods: some general principles for the recognition of palaeoenvironments. In: DeDeckker, P., Colin, J-P. and Peypouquet, P.; eds, Ostracoda in the Earth Sciences. Elsevier, New York, 245-256. Referred to in Wakefield, 1995, PGA, " Possible causes of mass mortality events in lagoonal environments are rapid increases in the relative sedimentation rate, or sudden and lethal changes in either salinity and/or water temperature, as have been suggested for similar occurences in the Purbeck Beds (Upper Jurassic) of the Dorset Coast, England (see Whatley, 1988).
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Wilkinson , I.P. 2007. The distribution of Late Kimmeridgian and Portlandian ostracoda in southern England. La répartition des ostracodes du Kimméridgien supérieur au Portlandien en Angleterre méridionale. Revue de Micropaleontologie. By Ian P. Wilkinson, British Geological Survey, Keyworth, Available online 1 October 2007.
Abstract: The vertical distribution of ostracods in the Upper Kimmeridgian and Portlandian (sensu anglico) succession in three cored boreholes at Hartwell, Tisbury and Fairlight, are compared to other successions in southern England. The Upper Kimmeridge Clay Formation yields rich, but low diversity ostracod faunas, characterised by stratigraphically restricted species of Aaleniella, Galliaecytheridea, Klentnicella, Macrodentina, Mandelstamia, Micrommatocythere, Paralesleya and Prohutsonia. Several continue into the Portlandian, but some species, belonging to genera such as Cytherelloidea, Paracypris, Fabanella, Galliaecytheridea, Klieana, Paraschuleridea, Eocytheridea, Paranotacythere, Procytheropteron, Rectocythere and Macrodentina, appear for the first time. Biostratigraphical subdivision is made difficult by provincialism caused by decreasing salinities and facies change during the Late Portlandian. Marine taxa such as Protocythere, Macrocypris, Paraschuleridea, Paranotacythere, Procytheropteron and Rectocythere were replaced by euryhaline forms, such as species of Fabanella and Mantelliana, and fresh-oligohaline species of the genera Cypridea, Scabriculocypris, Alicenula and Rhinocypris.
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Wolburg, J. 1959. Die Cyprideen des nw-deutschen Wealden. Senckenberg. leth., 40, 223-315.

Ostracod Palaeoenvironments
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Horne , D.J. 1995. A revised ostracod biostratigraphy for the Purbeck-Wealden of England. Cretaceous Research, 16, 639-663, Academic Press Ltd. The extensive work of the late F.W.Anderson on Purbeck-Wealden ostracods is critically reviewed. He used ostracods as the basis of four different kinds of stratigraphical subdivision in the English Purbeck-Wealden sequence: zones (based on the ranges of Cypridea species), faunicycles (based on alternations of assemblages dominated by Cypridea with assemblages dominated by other genera), 'beds' and 'assemblages' (both groupings of faunicycles). It is concluded that although Anderson's own correlations using these schemes might be regarded as reliable, all of them were so poorly defined as to preclude their use by future workers. Furthermore, erroneous zonation schemes have been propagated by other authors who mistook Anderson's assemblages for zones. In spite of criticisms of his applications and interpretations of ostracods, Anderson's data remain the best available for the Purbeck-Wealden of the Weald and Wessex sub-basins. As a solution to some of these problems, a new ostracod biozonation scheme is proposed, comprising three zones (Theriosynoecum forbesi Zone, approximately equal to the Purbeck; Theriosynoecum alleni Zone, approximately equal to the Hastings Beds Group; Theriosynoecum fittoni Zone, approximately equal to the Weald Clay Group), subdivided into eight subzones on the basis of the ranges of Cypridea species. [end of abstract]
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Wakefield , M.I. 1995. Ostracod biostratinomy at lagoonal shorelines: examples from the Great Estuarine Group, Middle Jurassic, Scotland. Proceedings of Geologists' Association, 106, 211-218. Some comparison with Purbeck. Darwinula develops during warmer months; Spring assemblages with older instars but without very young ones can be recognised. Darwinula lives 3 to 4 years. Cup-in-cup ostracods in Purbeck. Indicative of deposition at or just below the water's edge.
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Whatley , R.C. 1988. Population studies of ostracods: some general principles for the recognition of palaeoenvironments. In: DeDeckker, P., Colin, J-P. and Peypouquet, P.; eds, Ostracoda in the Earth Sciences. Elsevier, New York, 245-256. Referred to in Wakefield, 1995, Proceedings of the Geologists' Association, " Possible causes of mass mortality events in lagoonal environments are rapid increases in the relative sedimentation rate, or sudden and lethal changes in either salinity and/or water temperature, as have been suggested for similar occurences in the Purbeck Beds (Upper Jurassic) of the Dorset Coast, England (see Whatley, 1988).

Palaeoclimate

Allen, P. et al., 1998. Purbeck-Wealden (early Cretaceous) climates. Proceedings of the Geologists' Association, 109, 197-236. (Full list of authors: Allen, P, Alvin, KL, Andrews, JE, Batten, DJ, Charlton, WA, Cleevely, RJ, Ensom, PC, Evans, SE, Francis, JE, Hailwood, EA, Harding, IC, Horne, DJ, Hughes, NF, Hunt, CO, Jarzembowski, EA, Jones, TP, Knox, RWO, Milner, A, Norman, DB, Palmer, CP, Parker, A, Patterson, GA, Price, GD, Radley, JD, Rawson, PF, Ross, AJ, Rolfe, S, Ruffell, AH, Sellwood, BW, Sladen, CP, Taylor, KG, Watson, J, Wright, VP, Wimbledon, WA, Banham, GH ). Abstract: A multidisciplinary colligation including new data and analysis of the evidence for the climates of southern Britain during c. 140 Ma. to c. 120 Ma BP (Berriasian-Barremian - ? earliest Aptian). The climate was at first hot, semi-arid and 'Mediterranean' (rather than 'monsoonal') in type, probably with seasonally opposed winds (E/W). An irregular long-term trend of increasing rainfall in the moister seasons is evident. This was probably associated with establishment of predominant westerlies during the Jurassic-Cretaceous transition and slightly lower average annual temperatures thereafter until Barremian times. Causes proposed are frequent changes in the regional climatic system due to tectonically induced adjustments of relief under the special conditions of the semienclosed Purbeck-Wealden archipelago and increasing proximity of the widening Protoatlantic sea.

Allen, J.R.L. , Hoskins, B.J., Sellwood, B.W., Spicer, R.A. and Valdes, P.J. 1994. Palaeoclimates and their modelling. With special reference to the Mesozoic Era. The Royal Society and Chapman and Hall. ISBN 0 412 56330 4. 152 pp. . Reviewed by Jane Francis in Palaeontology Newletter No. 24. pp. 38-39. Royal Society meeting in 1993 aimed at bringing together people with geological data with computer modellers. Most connected with a Mesozoic modelling project at Reading University. Barron et al. on General Circulation Models for the Cretaceous. Seasonal variations considered and a more realistic mixed layer ocean. High CO2 important - x4-6 times present. Valdes on Kimmeridgian. Sellwood and Price on Mesozoic palaeoclimates and Hallam on Jurassic. Triassic and Jurassic plants - Ziegler. Geoscience Publishers.

Francis, J.E. 1983b. The Fossil Forests of the Basal Purbeck Formation, (Upper Jurassic) of Dorset, Southern England: Palaeobotanical and Palaeoenvironmental Investigations. Unpublished Ph.D. thesis, Southampton Univ., 295pp.

Francis, J.E. 1984. The seasonal environment of the Purbeck (Upper Jurassic) fossil forests. Palaeogeogr., Palaeoclimatol., Palaeoecol., 48, 285-307.

Francis, J.E. and Frakes, L.A. 19923. Cretaceous climates. In Wright, V.P., 19923, Sedimentology Review No. 1. 160pp., 80 illustrations, paperback.

Hallam, A., Grose, J.A. and Ruffell, A.H. 1991. Palaeoclimatic significance of changes in clay mineralogy across the Jurassic-Cretaceous boundary in England and France. Palaeogeography, Palaeoclimatology, Palaeoecology, 81, 173-187. Palygorskite recorded in lower Purbeck. Arid or semi-arid origin. South of France, Vocontian Basin, Speeton Clay. Speculations on the cause of end-Jurassic aridity. Uplift of Cimmerides in southern Eurasia may have isolated Europe from the near body of ocean water to the east (more important climatically than water to the west). Another possibility is that end-Jurassic uplift of the Arabian Shield, well attested by stratigraphic datsa from the Middle East had an orographic effect on regions further west.

Hurst, A. 1985. The implications of clay mineralogy to palaeoclimate during the Jurassic in N.E. Scotland. Scottish Journal of Geology, 2, 1 43-160. (Purbeck analogue)

Insalaco, E. 1996. The use of late Jurassic coral growth bands as palaeoenvironmental indicator. Palaeontology, 39, 413-431. Oxfordian, not Purbeck but relevant to Pb. No palaeolatitudinal gradient found but evidence for high seasonality in the belt north of Tethys.

Insole, A.N. and Hutt, S. 1994. The paleoecology of the dinosaurs of the Wessex Formation (Wealden Group, Early Cretaceous), Isle-of-Wight, Southern England. Zoological Journal of the Linnean society 112: (1-2) 197-215 Sept-Oct, 1994. Abstract: The Wessex Formation on the Isle of Wight yields an Early Cretaceous dinosaur fauna. Sedimentological evidence shows that this represents a mosaic of fluvial, floodplain and lacustrine environments within a relatively narrow east-west oriented valley. The vegetational cover on the alluvial plain had a savannah- or chaparral-like aspect, probably of low productivity. The relative scarcity of small aquatic vertebrates, absence of coals, abundance of oxidixed sediments and the presence of immature calcretes indicate seasonal water supply. The dinosaur taxa compising the Wessex Formation faunal assemblage represent a single palaeocommunity which inhabited the local alluvial plain, although some species may have been transient. The fauna had a relatively low diversity and this is attributed to the low productivity of the local vegetation. Iguanodontids and Hypsilophodon were the dominant elements in the fauna. In contrast to Late Jurassic dinosaur faunas, sauropods are less abundant in the Wessex Formation, although they remain taxonomically diverse. It is concluded that climatic changes which took place in the Late Jurassic or Early Cretaceous resulted in the appearance of low productivity vegetation and that this was incapable of supporting large sauropod populations. Authors address - Museum of Isle of Wight Geology, Sandown, Isle of Wight, PO36 8AF. Publisher Academic Press Ltd., London. (on the Wealden but relevant to Purbeck palaeoclimates)

Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. . Milankovitch cycles found by Fast Fourier Transform. Role of glacio-eustasy - see also Frakes and Francis 1988, Nature. Cyclic carbonate deposition. Sierra del Pozo region, southeast Spain, near the coast, north-east of Granada. Black pebbles. Evaporites. Birdseyes. Del 13C and del 18 O isotope data. Sr ppm. Sr high in subtidal facies. Sedimentation rate 12-15 cm per 1000 yrs (ie. about 0.13 mm per annum).

Kemper, E. 1987. Das Klima der Kreide-Zeit. Geologisches Jahrbuch, Reihe A, Heft 96.

Moore, G.T., Hayashida, D.N., Ross, C.A. and Jacobson, S.R. 1992. Palaeoclimate of the Kimmeridgian/Tithonian (Late Jurassic) world: 1. Results using a general circulation model. Palaeo., Palaeo., Palaeo., 93, No. 1/2, May 1992, 113- .

Pelzer, G. and Wilde, V. 1987. Klimatische Tendenzen wahrend der Ablagerung der Wealden-Fazies in Nordwesteuropa. Pp. 239-264 in Kemper, E. 1987. Das Klima der Kreide-Zeit. Geologisches Jahrbuch, Reihe A, Heft 96.

Ruffell, A. 1990. The Tithonian and Barremian arid phases in Europe and their effect on sequence stratigraphy. 13th Int. Sed. Congr., Nottingham (Arid phase in top Wessex Fm., Wealden, Isle of Wight with palygorskite). Similarities to Purbeck?

Ruffell, A. and Rawson, P.A. 1994. Palaeoclimate control on sequence stratigraphic patterns in the late Jurassic to mid-Cretaceous, with a case study from Eastern England. Palaeogeog, Palaeoclim, Palaeoecology, 110, 43-54. . Not . Sediment supply is a fundamental control on architecture of sediment sequences. During arid low sea-level phases clastic supply was reduced and long hiatuses are common at sequence boundaries or during maximum flooding. Hiatuses amalgamated when sediment starvation produced strongly condensed (super condensed) sections. In humid, high sea-level phases, clastic supply was more abundant; thick sediment packages separate sequence bundaries. Downlapping surfaces should be apparent and condensed sections rare. Mesozoic sequences include the arid (actually - semiarid) Purbeck Formation. Discussion of Spilsby Sandstone, Claxby, Tealby etc.

Sellwood, B.W. and Valdes, P.J. 1997. Geological evaluation of climate: General Circulation Models and model implications for Mesozoic cloud cover. Terra Nova, 9, 75-78. (Copies in box in Short Loan - SOC Library). General Circulation Models (GCMs) are currently used to predict future global change. However, the robustness of GCMs can, and should, be evaluated by their ability to simulate past climate regimes. Their success in " retrodiction " can then be assessed by reference to the testimony of the geological record. Geological evidence provides a database which can be used in the estimation of sea surface temperatures and other proxy data useful in paleaoclimatic studies. These data can then be used to refine the prescribed boundary conditions for running GCMs themselves. Results of modelling experiments confim a generally warmer Mesozoic earth with arid tropics and convective rainfall higher over the oceans than at present. Circum-polar wetlands are also indicated. Modelled cloudiness is also higher in the Mesozoic, contributing to greenhouse conditions and possibly influencing terrestrial biomes and marine ecosystems. (Authors' abstract). Authors - Bruce Sellwood at Postgraduate Research Institute for Sedimentology, The University, Whiteknights, Reading , RG6 2AB, UK. Paul Valdes - Department of Meteorology, Reading. See also other Valdes and Sellwood papers on this topic in reference list of this paper.

Spicer, R.A. 1987. The significance of the Cretaceous flora of northern Alaska for reconstruction of the climate of the Cretaceous. Pp. 265-292 in Kemper, E. 1987. Das Klima der Kreide-Zeit. Geologisches Jahrbuch, Reihe A, Heft 96.

Vakhrameev, V.A. 1991. Jurassic and Cretaceous Floras and Climates of the Earth. 340p.

Valdes, P. J. 1990. The seasonality of climate during the Jurassic. 13th Int. Sed. Congress Nottingham, Abstracts, p. 566.

Valdes, P.J. and Sellwood, B.W. 1992. A palaeoclimate model for the Kimmeridgian. Palaeo, Palaeo, Palaeo, 95, 47-72. No ice , seasonally arid climate over southern Europe.

Wignall, P. 1988. Sudden climatic changes in the Kimmeridgian of Northwest Europe. Abstract for Lyell Meeting of the Geological Society on 23 Feb. 1989. (Leicester University). Geological Society Newsletter, Jan 1989, vol. 18, no. 1, p. 9 only.

Palaeoenvironments

Jarzembowski, E.A. 1995. Early Cretaceous insect faunas and palaeoenvironment. Cretaceous Research, 16 , 681-694.

Radley, J. 198? Purbeck and Portland Gastropods. M.Sc. Thesis. Extracts in . Full title not known. True low salinity gastropod faunas in vertual evolutionary stasis since their appearance in the Jurassic. Much Buckinghamshire information in thesis although only small amount in this extract. Aptixiella portlandica - occurrence and mode of life. Micromorphic gastropod faunas of "algal meadows". Valvata, Hydrobia, Natica, Bathrotomaria Aylesbury, Creamy Limestones Chilmark Tisbury Ragstones Shotover.

Wakefield, M.I. 1995. Ostracod biostratinomy at lagoonal shorelines: examples from the Great Estuarine Group, Middle Jurassic, Scotland. Proceedings of the Geologists' Association, 106, 211-218. Some comparison with Pb. Darwinula develops during warmer months; Spring assemblages with older instars but without very young ones can be recognised. Darwinula lives 3 to 4 years. Cup-in-cup ostracods in Purbeck. Indicative of deposition at or just below the water's edge.

Whatley, R.C. 1988. Population studies of ostracods: some general principles for the recognition of palaeoenvironments. In: DeDeckker, P., Colin, J-P. and Peypouquet, P.; eds, Ostracoda in the Earth Sciences. Elsevier, New York, 245-256. Referred to in Wakefield, 1995, PGA, " Possible causes of mass mortality events in lagoonal environments are rapid increases in the relative sedimentation rate, or sudden and lethal changes in either salinity and/or water temperature, as have been suggested for similar occurences in the Purbeck Beds (Upper Jurassic) of the Dorset Coast, England (see Whatley, 1988).

West, I.M. 1979. Sedimentary Environments and Diagenesis of Purbeck Strata (Upper Jurassic - Lower Cretaceous) of Dorset, U.K. Unpublished Ph.D. Thesis, Southampton University, 181 pp.

West I.M. and Clayton, T. in: Taylor, K.G. and Ruffell, A.H. 1993. Early Cretaceous environments. Conference Report. Journal of the Geological Society, London, 150, 413-414. I.M. West and T. Clayton (Southampton University) showed how the chemistry of evaporitic minerals can record changing conditions in the Purbeck Formation of southern England. In the basal parts of the Formation, low-Mg evaporites formed in lagoonal conditions with open access to the sea. Later closure of this led to precipitation of high-Mg minerals within a lacustrine environment. The incoming of humid conditions led to the influx of detrital material into this lacustrine environment, but the formation of Mg calcite indicates the continuation of a closed system.

West, I.M., Ali, Y.A. and Hilmy, M.A. 1986. Facies associated with primary gypsum nodues of the northern Egyptian sabkhas. Pp. 171-183 in: Sixth International Symposium on Salt, 1983, vol. 1. Published by the Salt Institute, 206 North Washington Street, Alexandria, Virginia, 22324, USA. (Discusses analogy between dwarfed Cardium glaucum in hypersaline Egyptian coastal lagoons and the small Protocardia purbeckensis, the Purbeck "cockle" of hypersaline parts of the Lower Purbeck Formation of Dorset.)

Palaeosalinity

Allen, P. and Keith, M.L. 1965. Carbon isotope ratios and paleosalinities of Purbeck-Wealden carbonates. Nature, 208, 1278-1280.

Brown, P.R. 1964. Petrography and origin of some upper Jurassic beds from Dorset, England. Journal of Sedimentary Petrology, 34, 254-269.

Brown, P.R. 1961. Petrology of the Lower and Middle Purbeck Beds of Dorset. Unpublished Ph.D. thesis, Liverpool University, 205p.

Gray, J. 1988. Evolution of the freshwater ecosystem: the fossil record. Palaeogeography, Palaeoclimatology, Palaeoecology, Special Issue, Aspects of Freshwater Paleoecology and Biogeography (Gray, J. editor), 62, 1-214

West, I.M. 1979. Sedimentary Environments and Diagenesis of Purbeck Strata (Upper Jurassic - Lower Cretaceous) of Dorset, U.K. Unpublished Ph.D. Thesis, Southampton University, 181 pp.

West, I.M., Ali, Y.A. and Hilmy, M.A. 1986. Facies associated with primary gypsum nodues of the northern Egyptian sabkhas. Pp. 171-183 in: Sixth International Symposium on Salt, 1983, vol. 1. Published by the Salt Institute, 206 North Washington Street, Alexandria, Virginia, 22324, USA. (Discusses analogy between dwarfed Cardium glaucum in hypersaline Egyptian coastal lagoons and the small Protocardia purbeckensis, the Purbeck "cockle" of hypersaline parts of the Lower Purbeck Formation of Dorset.)

Palaeogeography

Garden, I.R. 1991. Changes in the provenance of pebbly detritus in southern Britain and northern France associated with basin rifting. In Morton, A.C., Todd, S.P. and Haughton, P.D.W. (eds.), 1991. Developments in Sedimentary Provence Studies. Geological Society Special Publication, No. 57, 273-289. . Upper Jurassic and Lower Cretaceous pebble suites of southern Britian and Normandy are separable into six assemblages. Assemblage 1 - Carboniferous shelf chert. Assemblage 2 - Quartz with Carb. basinal chert and with some Jurassic (including Purbeck) chert. Sourced from Cornubia. Assemblage 3 - Carb. shelf chert with silic. volcanics. From Welsh massif. Lower Greensand pebble beds. Some Jurassic material. Assemblage 4 - Quartz with sandstone and some Carb. shelf chert. Kent. Source Anglo Brabant massif. Assemblage 5 - Quartz Carb. shelf chert. Lincolnshire. From northern Anglo-Brabant Massif. Assemblage 6 -Quartz with some Jurassic material. Normandy. From Cotentin High. Mesozoic cherts include silicified evaporites and silificied wood. Portland and Pb. cherts locally common in Wessex and Gault of Dorset and scarce in Lower Greensand of the Isle of Wight Allen (1960) reported Portland chert in Hasting Group of Weald and West and Hooper (1969) in the Purbeck of Dorset (and phosphate). Some useful palaeogeographic maps.

Smith, A.G., Smith, D.G. and Funnell, B.M. 1994. Atlas of Mesozoic and Cenozoic Coastlines. Geoscience Intercept Ltd, Andover, 112pp. Thirty-one maps corresponding to stages. Although a computer study based on new data it only refines the earlier maps. See map 19, p. 42 - Valanginian - Barremian map.

West, I. M. 1992. Contribution on Purbeck Formation in: Cope, J.C.W., Ingham, J.K. and Rawson, P.F. (editor). 1992. Atlas of Palaeogeography and Lithofacies. Geological Society of London.

Palaeosols (see also Dirt Beds, Caliche, Black Pebbles)

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Andrews , J.E. 1988. Soil-zone microfabrics in calcrete and in desiccation cracks from the Upper Jurassic Purbeck Formation of Dorset. Geological Journal, 23, 261-270. [Alveolar septal structure, needle fibre, desiccation cracks, calcrete.]
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Francis , J.E. 1983. The Fossil Forests of the Basal Purbeck Formation (Upper Jurassic) of Dorset, Southern England. Ph.D. Thesis (unpublished), University of Southampton.

.
West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium - Sedimentation Jurassique W. Europeen. A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

Palustrine Facies

Platt, N.H. 1991. Lacustrine carbonates and pedogenesis: sedimentology and origin of palustrine deposits from the Early Cretaceous Rupelo Formation, W. Cameros Basin, N. Spain. Reprinted from Sedimentology, 1989, 665-684. Pages 323-342 in the present book. In: Wright, V.P. and Tucker, M.E. (1991) Calcretes. International Association of Sedimentologists, Reprint Series, 2, 352. Blackwell Scientific Publications. Oxford. 471 Charophytes, ostracods, gastropods and rare vertebrates. Silicified evaporites found near the top of the sequence. Stable isotope analysis. del 13C for -7 to -11 and del 18 O from -3 to -7.5. Palustrine limestones formed through pedogenic modification of lake carbonate. Low gradient, low energy, unstratified lake. Berriasian. Dark intraclasts like black pebbles.

.

Palynology, Purbeck

Allen, P. and Wimbledon, W.A. 1991. Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas. Cretaceous Research, 12, 511-526. .

Batten, D.J. 1982. Palynofacies and salinity in the Purbeck and Wealden of southern England. In Banner, F.T. and Lord, A.R. 1982. Aspects of Micropalaeontology, pp. 278-308.

Burger, D. 1966. Palynology of uppermost Jurassic and lowermost Cretaceous strata in the Eastern Netherlands. Overdruk uit Leidse Geologische Mededelingen, deel 35, Blz 209-276.

Couper, R.A. 1958. British Mesozoic microspore and pollen grains. A systematic and stratigraphic study. Palaeontographica B 103, 75-179.

Lister J. K.; Batten, D. J. 1988. Stratigraphic and palaeoenvinronmental distribution of Early Cretaceous dinoflagellate cysts in the Hurlands Farm Borehole, West Sussex, England. Palaeontogr., abt. b., Stuttgart, 1988, 210 (1-3) 9-89 Bundesanstalt fuer Geowissenschaften Rohstoffe (BGR, Federal Republic of Germany)

Norris, G. 1969. Miospores from the Purbeck Beds and marine Upper Jurassic of southern England. Palaeontology, 12, 574-620.

Norris, G. 1985. Correspondence: Palynology and British Purbeck Facies. Geological Magazine, 122, 187-190.

Palynology, Purbeck Equivalents in other Regions

(Only a few references only will be added as examples)

Taxonomy and biostratigraphy of schizaealean spores from the Jurassic-Cretaceous boundary beds of the Aklavik Range, District of Mackenzie. Palaeontographica Canadiana no. 4. Extract: Contents: Abstract. Résumé. Introduction and Acknowledgements. Geological Setting. Chronostratigraphic Terminology and Definitions. Tectono-stratigraphic Setting. Lithostratigraphic Units. General Remarks. Husky Formation. Martin Creek Formation. McGuire Formation. Fault Creek Formation. Lower Canyon Formation. Material General Botanical and Palynological Considerations. Classification and Nomenclature of Fossil Dispersed Spores. Botanical Affinity. Terminology. Systematic Paleontology. Dispersed ?Anemiaceous Miospores. Genus Contignisporites. Contignisporites sp. cf. C. glebulentus. Genus Crassitudisporites Crassitudisporites problematicus. Genus Cicatricosisporites. etc. etc. Part of Web Site - Publications of the Geological Association of Canada including Books, Journals, Special Papers, etc. Extract: Complete list of publications, journals, Geolog, special papers, Geoscience Canada reprint series, Nuna, Geotext, special interest, short course notes, division publications: volcanology, mineral deposits, paleontology, section publications, Palaeontographica Canadiana, new publication initiatives, GAC anniversary specials. (Visited 26th November, 1997.**)

Petrography

Brown, P.R. 1964. Petrography and origin of some Upper Jurassic Beds from Dorset, England. J. sediment. Petrology, 34, 254-269.

Brown, P.R. 1966. Pyritization in some molluscan shells. Journal of Sedimentology Petrology, 36, 1149-1152.

El-Shahat, A. 1977. Petrography and Geochemistry of a Limestone-Shale Sequence with Early and Late Lithification: the Middle Purbeck of Dorset, England. Unpublished Ph.D. thesis, Southampton Univ., 358pp.

El-Shahat, A. and West, I.M. 1983. Early and late lithification of aragonitic bivalve beds in the Purbeck Formation (Upper Jurassic-Lower Cretaceous) of southern England. Sediment. Geol., 35, 15-41.

Fuchtbauer, H. and Goldschmidt, H. 1964. Aragonitische Lumachellen im bituminosen Wealden des Emslandes. Beitr. Mineral. Petrogr., 10, 184-197.

Hudson, J.D. 1962. Pseudo-pleochroic calcite in recrystallised shell limestones. Geological Magazine, 99, 492-500.

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium "Sedimentation Jurassique W. Europeen." A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

Peveril Point, Swanage, Dorset

Clements, R.G. 1969. Annotated cumulative section of the Purbeck beds between Peveril Point and the Zig-zag path, Durlston Bay. In: H.S. Torrens (Ed.) International Field Symposium on the British Jurassic, Excursion No. 1, Guide for Dorset and South Somerset. University of Keele, pp. 44-71. 71p. total. .

Clements, R.G. 1993. Type-section of the Purbeck Limestone Group, Durlston Bay, Swanage, Dorset. Proceedings of Dorset Natural History Archaeological Society, 114 for 1992, 181-206. Classic section log

Cosgrove, M.E. and Hearn, E.W. 1966. Structures in the Upper Purbeck Beds at Peveril Point, Swanage, Dorset. Geological Magazine, 103, No.6, 498-507. Bulge structure.

Nunn, J.F. 1992. A geological map of the Purbeck Beds in the northern part of Durlston Bay. Proceedings of Dorset Natural History Archaeological Society, 113, 145-148. . Two photographs (Figs. 2a, 2b) of the southern Peveril Anticline are shown at a time when it was well-exposed because of a storm. It is now (1993) concealed.

West, I.M. 1964. Deformation of the incompetent beds in the Purbeck Anticline. Geological Magazine, 101, p.373.

Pewsey, Vale of (southern England)

Barron, R.S. 1957. Field meeting at Pewsey Vale and Devizes District. Proceedings of the Geologists' Association, London, 68, 228-230.

Portesham Charophyte Chert

(unuusual chert with freshwater fossils and pseudomorphs after lenticular gypsum crystals, at Portesham Rocket Quarry, Dorset)

Bandel, K. 1991. Gastropods from brackish and fresh water of the Jurassic -Cretaceous transition (a systematic reevaluation). Berliner geowissenschaftliche abhandlungen, Reiche A, Band 134, Berlin, 1991, pp. 9-55. Abstract: From the Purbeckian facies of the Upper Jurassic and Lowermost Cretaceous 23 species of gastropods that have lived in coastal swamps in brackish or fresh water have been studied. Special emphasis was placed on the morphology of their early ontogenetic shell. In many cases the shape and orientation of the first whorls of the shell could be utilized to find a more appropriate place within the system of gastropods than had been suggested before and correlate the fossil species with their modern relatives. The Purbeckian fauna is compared with the modern gastropods living in similar environment. End of authors abstract. My notes - Land snails are recorded from Switzerland. Some Hydrobias become Proauriculastra. Portesham charophyte chert referred to. Physa becomes Prophysa. Planorbic becomes Gyraulus. Some Jura Mountain sections described by Mojon (in a thesis) are given. They are quite detailed. .

Barker, D., Brown, C.E., Bugg, S.C. and Costin, J. 1975. Ostracods, land plants and charales of the basal Purbeck Beds of Portesham Quarry. Palaeontology, 18, 419-436.

Feist, M., Lake, R.D. and Wood, C.J. 1995. Charophyte biostratigraphy of the Purbeck and Wealden of southern England. Palaeontology, 38, 407-442. Purbeck and Wealden charophytes, mostly from the Weald area. A new set of charophte zones. Lowest is Globator rectispirale. Clavator westii is considered and said to be indeterminate. The Jurassic Cretaceous boundary is located within the Lulworth Formation.
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West, I.M. 1961. Lower Purbeck Beds of Swindon Facies in Dorset. Nature, London, 190, p.526.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand. Portesham section.]

Portland, Isle of

Dorset, southern England. Purbeck strata cap the Portland Stone and extend up to the Soft Cockle Member with gypsum - Portland Alabaster, which is in places partially replaced by celestite.

Bosence, D.W.J., Ali, O., Goldring, R. and Riding, R. 1987. Mesozoic platform carbonate and benthic calcareous algae of the Severn and Wessex Basins. Section on: Purbeck and Portland Formations of the Isle of Portland. In: 4th International Symposium on Fossil Algae, Cardiff, 1987, Pre-Symposium Field Excursion. Excursions Guide. Edited by Robert Riding. (not paginated throughout). Burrowed thrombolites, stromatolites, freshwater theory etc. In contrast to previous theories of high salinity origin of the stromatolites, cheironomid burrows were used as low salinity evidence. It should be noted, however, that Cornee et al. (1992) report that chironomids can tolerate salinities up to almost 100 parts per thousand. There is evaporite evidence against the freshwater Portland tufa arguments, and the apparent anomaly may in the future be resolved when more is discovered about modern hypersaline lacustrine stromatolites. This is a very useful and interesting publication.

Francis, J. 1983. The dominant conifer of the Jurassic Purbeck Formation, England. Palaeontology, 26, 277-294. See also Francis Thesis and various Purbeck tree papers, referred to above. Material from quarry at Godnor, Isle of Portland etc. Change in Great Dirt Bed facies to the south.

Neve, J. 1992. The Portland and Basal Purbeck Regression Deposits of the Isle of Portland, Dorset. B.Sc. (Hons.) Undergraduate Research Project, Dept. of Geology, Southampton University, April 1992. 51p. . Also Staff . Bowers Quarry extension, Portland. Portland limestone and lowest part of Purbecks. Palygorskite in lower dirt beds. See also Niblett, Ruth 1992 project on the Purbeck succession on the same quarry.

Niblett, Ruth, 1992. The Lower Purbeck Formation (Upper Jurassic) of Bowers Quarry, Northwestern Portland. Unpublished Undergraduate Research Project, April 1992.

Perry, C.T. 1994. Freshwater tufa stromatolites in the Lower Purbeck Beds (Upper Jurassic), Isle of Portland, Dorset. Geological Journal, 29, 1129-135. Controversial - lack of freshwater gastropods etc . An abstract has been published as Perry, 1992 .

Perry, C.T. unpublished 1993. Freshwater tufa stromatolites in the Lower Purbeck Beds (Upper Jurassic), Isle of Portland, Dorset. Referreed for Geological Journal in 1993 by me. Controversial . See discussion about Cheironomids re Bosence, above.

Pugh, M. 196? (about 1962?) M.Sc. Thesis on Purbeck Formation. Section on Portland with petrography. Evaporites.

Shapley, Brian. 1994. Unpublished letter. Carrying out undergraduate project on two small river channels just below a palaeosol on Portland Bill at SY369070 (Godnor area?). Below the Lower Dirt Bed or Great? West London Institute of Higher Education, Brunel.

West, I.M. 1975. Evaporites and associated sediments of the basal Purbeck Formation (Upper Jurassic) of Dorset. Proceedings of the Geologists' Association, London, 86, 205-225. Abstract: Four facies of limestones, each with particular contents of calcitised evaporites and of skeletal debris were recognised. They are compared with sediments of modern evaporite-depositing environments. The lowermost limestones, stromatolitic and pelletoid with foraminifera, probably originated in intertidal to shallow subtidal, moderately hypersaline, water. Overlying pelletoid limestones with algal-mats and some gypsum are products of high-intertidal flats. The main evaporite beds were originally gypsum, probably formed in supratidal to intertidal, very hypersaline, palaeoenvironments. The gypsum was converted to anhydrite and later brecciated in part, forming the Broken Beds. Extensive calcitisation produced porous unfossiliferous limestones. Ostracodal limestones above probably originated in shallow, only moderately hypersaline water. All the basal Purbeck strata were formed in and around a large shallow gulf with extensive tidal flats and with water of varying but predominantly high salinities. At times of uplift, thin soils developed on the former margins of the gulf. Forests were able to exist there because, although the area was within the semi-arid zone, it was probably very near to the boundary of the warm-temperate zone. End of Abstract. [Additional notes on topics discussed: Palaeosalinity origins of the basal Purbeck facies and lateral correlation. Mostly hypersaline to varying extents, including the stromatolite horizons. Fossil trees 'pickled' in a salt lake. Details of the basal Purbeck strata at all the main localities, studied petrographically. Depositional environments of the dirt beds and marls. Palaeoenvironmental significance of sedimentary cyles. Thickness variations of the facies. Relationship of the Broken Beds to the evaporitic facies. Local uplift. Penecontemporaneous fault movement. The Mupe Bay oil sand.]

West, I.M. 1973. Vanished evaporites - significance of strontium minerals. Journal of Sedimentology Petrology. 43, 278-279. [Relevant to Portland celestite and evaporites (lower Purbeck).]

West, I.M., Shearman, D.J. and Pugh, M.E., 1969. Whitsun Field Meeting in the Weymouth Area, 1966. Proceedings of the Geologists' Association, 80, 331-340.

West, I.M., Shearman, D.J. and Pugh, M.E., 1969. Whitsun Field Meeting in the Weymouth Area, 1966. Proceedings of the Geologists' Association, 80, 331-340.

Provenance of Clastics

Garden, I.R. 1991. Changes in the provenance of pebbly detritus in southern Britain and northern France associated with basin rifting. In Morton, A.C., Todd, S.P. and Haughton, P.D.W. (eds.), 1991. Developments in Sedimentary Provenance Studies. Geological Society Special Publication, No. 57, 273-289.

Pseudopleochroic Calcite

Maliva R. G. and Dickson J. A. D. 1992. The mechanism of skeletal aragonite neomorphism: evidence from neomorphised mollusks from the Upper Purbeck Formation (Late Jurassic-Early Cretaceous), southern England. Sedimentary Geology, p. 221.

Pterosaurs, Pterodactyls .

Go to Purbeck Dinosaurs and other Vertebrates

.

Pyrite

Brown, P.R. 1966. Pyritization in some molluscan shells. Journal of Sedimentology Petrology, 36, 1149-1152.

Quarries and Quarrying

See also Building Stone

Reptila - General

See also Pterosaurs, Dinosaurs, etc

Delair, J.B. 1957. The Mesozoic reptiles of Dorset: Part One . Proceedings of Dorset Natural History Archaeological Society, 79, (1958), 47-72.

Delair, J.B. 1958. The Mesozoic reptiles of Dorset: Part Two . Proceedings of Dorset Natural History Archaeological Society, 80, (1959), 52-90.

Delair, J.B. 1959. The Mesozoic reptiles of Dorset: Part Three. Proceedings of Dorset Natural History Archaeological Society, 81, (1960), 59-85.

Delair, J.B. 1965. New records of dinosaurs and other fossil reptiles from Dorset. Proceedings of Dorset Natural History Archaeological Society, 87, (1966), 57-66.

Delair, J.B. 1973. The dinosaurs of Wiltshire. Wiltshire. Archaeological and Natural History Magasine, 68, 1-7.

Delair, J.B. 1991. The occurrence of megalosaurs in the Portlandian of Dorset. Proceedings of Dorset Natural History Archaeol. Society, 113 (1992), p. 196.

Delair, J.B. 1993. Reptilia from the Portland Stone (Upper Jurassic) of England: a preliminary survey of the material and the literature. Modern Geology, 18, 331-348. Keywords - reptiles, crocodiles, pterosaurs, ichthyosaurs, plesiosaurs, pliosaurs, dinosaurs, turtles, chelonia, bones, Portlandian, Upper Jurassic, Dorset, Wiltshire, Swindon, Chilmark, Buckinghamshire, Megalosaurus, Iguanodon, Pleurosternum, Stegochelys, Ornithopsis, Haysom's Quarry, St Aldhelm's Head, Muraenosaurus, Colymbosaurus, Broadcroft, Whitenothe, Seacombe, Preston, Church Ope Cove, Garsington, Great Hazeley, Aylesbury, Thame, Shotover, Metriorhynchus, Okus Quarry, Town Gardens, Tisbury, Stegosaur, Theropod, Ornithopod, Goniopholis, Bernissartia, dwarf crocodiles, fabrosaurs, lizards. I believe that wing bones from a pterodactyle from the "rubble" bed of Church Ope Cove and retained in the Portland Museum is probably Purbeck rather than Portland as listed in this paper but the matter requires checking. See Damon for use of the term "rubble" for Purbeck of Portland from above the Great Dirt Bed.

Delair, J.B. and Sarjeant, W.A.S. 1975. The earliest discoveries of dinosaurs. Isis, 66 (231), 5-25.

Delair, J.B. and Vaughan, R.F. 1992. The first record of Portlandian plesiosaurs from Swindon, Wiltshire. Wiltshire Archaeological and Natural History Magazine, 85, 121-127.

Ensom, P.C., Evans, S.E. and Milner, A.R. 1991. Amphibians and reptiles from the Purbeck Limestone Formation (Upper Jurassic) of Dorset. 5th Symposium on Mesozoic Terrestrial Ecosystems and Biota. Extended Abstracts, Oslo. . 19-20. Also with paper on mammals by Kielan-Jaworowska, Z. and Ensom P.C. Suprageneric taxa of late Jurassic and early Cretaceosus multituberculate mammals. pp. 35-36. ,.

Owen, R. 1841. Report on British fossil reptiles. Report of the British Association for the Advancement of Science, (Plymouth: 1842), 60-204.

Owen, R. 1849-1884. A History of British Fossil Reptiles. London, Cassell and Co. 4 vols.

Owen, R. 1854. A Descriptive Catalogue of the Fossil Organic Remains of Reptiles and Pisces contained in the Museum of the Royal College of Surgeons of England. London: Royal College of Surgeons, 184 pp.

Spamer, E.E., Bogan, A.E. and Torrens, H.S. 1989. Recovery of the Ethelred Benett collection of fossils mostly from the Jurassic-Cretaceous strata of Wiltshire, England, analysis of the taxonomic nomenclature of Benett (1831), and notes and figures of type specimens contained in the collection. Proceedings of Academy of Natural Science Philadelphia, 141, 115-180.

Wimbledon, W.A. 1995, in Benton, M.J. and Spencer, P. (eds). Fossil Reptiles of Great Britain. Chapman and Hall, p. 205.

Woodward, A.S. 1887. The history of British fossil crocodiles. Proceedings of the Geologists' Association, 288-344.

Reptilia, Lizards, Lacertilia

Evans, S.E. 1994. A new anguimorph lizard from the Jurassic and Lower Cretaceous of England. Palaeontology, 37, 33-49. Lizard - Parviraptor from the Purbeck, Beccles' collection.

Rock Terms (Names of Beds etc)

Arkell, W.J. and Tomkieff, S.I. 1953. English Rock Terms. Oxford University Press, Oxford, 130 p.

.

Ridgeway

Upwey area north of Weymouth Dorset - a railway cutting with old quarries nearby.

See also Upwey

Fisher, O. 1856. On the Purbeck strata of Dorsetshire. Transactions Cambridge Philosophic Society, 9, 555-581. Log of strata no longer well-exposed.

Weston, C.H. 1849. Further observations on the geology of Ridgway near Weymouth. Quarterly Journal of the Geological Society London. 4, 245-256.

Weston, C.H. 1852. On the sub-escarpments of the Ridgway Range, and their contemporaneous deposits in the Isle of Portland. Quarterly Journal of the Geological Society, London, 8, 110-120.

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Quarries and Quarrying

Arkell, W.J. and Tomkieff, S.T. 1953. English Rock Terms. Oxford, 139p.

Benfield, E. 1940. Purbeck Shop: A Stoneworker's Story of Stone. Cambridge University Press. Cambridge, 172 p.

Ensom, P.C. 1988. Excavations at Sunnydown Farm, Langton Matravers, Dorset: Amphibians discovered in the Purbeck Limestone Formation. Proceedings of Dorset Natural History Archaeological Society, 109, 148-150. Sauropod footprints, salamanders, multituberculate mammals. Iguanodon footprints. Cherty Freshwater Member. Also see paper in Palaeontology giving full description of mammals.

Kielan-Jaworowska, Z. and Ensom, P.C. 1994. Tiny plagiaulacoid multituberculate mammals from the Purbeck Limestone Formation of Dorset, England. Palaeontology, 37, 17-31. Sunnydown Farm, Cherty Freshwater Member, Langton Matravers, rodents, sieved sediments.

Legg, R. 1989. Purbeck Island: The Industrial, Social and Natural History of a Corner of England. First Published 1972, Second Revised Edition 1989. Dorset Publishing Company at the Wincanton Press, Wincanton, Somerset. 230 pp. ISBN 0 948699 08 6. See Chapter 3 - The Great Stone Quarries, pp 19-40.

Pushman, D. 1987 Precious Stone of Dorset. David Pushman. 128 p. ISBN 0 902129 937. This is not a geological publication but a broad anecdotal discussion about the Whitehall Cenotaph of Portland Stone, its history and significance to the author. It contains some useful quarry information, including information on the quarry from which the cenotaph stone was extracted. In particular it includes a copy of an old list of Purbeck bed names. There is some discussion of inland quarries of the Isle of Purbeck. It is written in an unusual style - "Where, oh where, was the cadaver? I scanned every wall. It was voluptuous May."

Pushman, D. 1995. Purbeck Underground. David Pushman, Downshay, The Hyde, Langton Matravers, Dorset. 77p. ISBN 0 9517621 1 7.

Robinson, C.E. c.1882. Picturesque Rambles in the Isle of Purbeck. London.

Saville, R.J. 1973. Ancient Order of Purbeck. Langton Matravers Historical and Preservation Society, Booklet No. 10.

Saville, R.J. 1976. The Stone Quarries of Langton Matravers. Langton Matravers Historical and Preservation Society, Booklet No 15.

West, I.M., 1988. Notes on some Purbeck sediments associated with the dinosaur footprints at Sunnydown Farm, near Langton Matravers, Dorset. Proceedings of the Dorset Natural History and Archaeological Society , 109, 153-154.

Reptiles - General

See also Turtles, Dinosaurs, Crocodiles

Delair, J.B. 1957. The Mesozoic reptiles of Dorset. Part 1. Proceedings of Dorset Natural History and Archaeological Society for 1957. vol. 79, 47-72. ?

Reworking of detritus and fossils

(See also Detritus)

Ensom, P. C. 1985a. Derived fossils in the Purbeck Limestone Formation, Worbarrow Tout, Dorset. Proceedings of Dorset Natural History and Archological Society, 106, 166.

Garden, I.R. 1991. Changes in the provenance of pebbly detritus in southern Britain and northern France associated with basin rifting. In Morton, A.C., Todd, S.P. and Haughton, P.D.W. (eds.), 1991. Developments in Sedimentary Provenance Studies. Geological Society Special Publication, No. 57, 273-289.

Ringstead

Arkell, W.J. 1951. The structure of Spring Bottom Ridge, and the origin of the mud-slides, Osmington, Dorset. Proceedings of Geol.ogists' Association, London. , 62, 21-30. Map showing distribution of Lower, Middle and Upper Purbeck in this area.

Sabkha Cycles

Shearman, D.J.. (1966) Origin of marine evaporites by diagenesis: Institute Min. Metall. Transactions , 75, B 717, 208-215.

West, I.M., 1979. Review of evaporite diagenesis in the Purbeck Formation of southern England. Symposium "Sedimentation Jurassique W. Europeen." A.S.F. Publication Speciale, No.1, Mars 1979. 407-416.

Sea-Level Changes

Hallam, A. 1977.

Hallam, A. 1988.

Haq et al. 1988. Mesozoic and Cenozoic chronostratigraphy and cycles of sea level change. In: Sea Level Changes: an Integrated Approach (eds Wilson et al.) SEPM spec. Publ. 42, 71-108. (full ref in Allen and Wimbledon, 1991)

Rawson and Riley. 1982.

Ruffell, A. 1991. Sea-level events during the Early Cretaceous in Western Europe. Cretaceous Research, 12, 527-551. A Europe-wide sea-level lowstand in the latest Jurassic- earliest Cretaceous has been interpreted by Hallam (1977, 1988), Rawson and Riley (1982) and Haq et al. (1988) as a second order sea level fall.

Sedimentary Structures

.

Sedimentation Rates

Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. . Milankovitch cycles found by Fast Fourier Transform. Role of glacio-eustasy - see also Frakes and Francis 1988, Nature. Cyclic carbonate deposition. Sierra del Pozo region, southeast Spain, near the coast, north-east of Granada. Black pebbles. Evaporites. Birdseyes. Del 13C and del 18 O isotope data. Sr ppm. Sr high in subtidal facies. Sedimentation rate 12-15 cm per 1000 yrs (ie. about 0.13 mm per annum).

Seismic Stratigraphy

Ruffell, A. 1995. Seismic stratigraphic analysis of non-marine Lower Cretaceous strata in the Wessex and North Celtic Sea Basins. Cretaceous Research, v. 16 (No. 6 ), 603-638.

Sequence Stratigraphy

Burgess, P.M. et al. 1996. Sequence Stratigraphy in British Geology. Geological Society Special Publication, No. 103, 384 pp.

Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. . Milankovitch cycles found by Fast Fourier Transform. Role of glacio-eustasy - see also Frakes and Francis 1988, Nature. Cyclic carbonate deposition. Sierra del Pozo region, southeast Spain, near the coast, north-east of Granada. Black pebbles. Evaporites. Birdseyes. Del 13C and del 18 O isotope data. Sr ppm. Sr high in subtidal facies. Sedimentation rate 12-15 cm per 1000 yrs (ie. about 0.13 mm per annum).
.
Ruffell , A. 1995. Seismic stratigraphic analysis of non-marine Lower Cretaceous strata in the Wessex and North Celtic Sea Basins. Cretaceous Research, 16, 603-638.

Ruffell, A.H. and Rawson, P.F. 1994. Paleoclimate control on sequence stratigraphic patterns in the Late Jurassic to Mid Cretaceous, with a case-study from Eastern England. Palaeogeography, Palaeoclimatology, Palaeoecology, 110, 43-54. Abstract: Sediment supply is a fundamental control on the architecture of sedimentary sequences. In clastic depositional environments, the volume of sediment being transported into the basin of deposition is strongly dependent on both the nature of the weathering regime in the hinterlands, and on runoff. During arid, low sea-level phases in the late Jurassic and early-mid-Cretaceous, clastic supply was reduced and long hiatuses became common at sequence boundaries or during maximum flooding. These hiatuses amalgamated where sediment starvation produced strongly condensed (''super-condensed'') sections. In intervening humid, higher sea-level phases, clastic supply was more abundant: hence thick sediment packages separate sequence boundaries, downlapping surfaces should be apparent on seismic sections, and condensed sections become rare. Where carbonate deposition dominates over clastic, sediment formation is largely intrabasinal and the effects of palaeoclimate on sequence stratigraphy are less obvious. Knowledge of palaeoclimates may lead us to search for certain sequence stratigraphic patterns connected to changes in sediment supply.

Serpulids

(Worm tubes common in the Soft Cockle Member of Dorset and abundant in the Serpulite of Germany. Serpula coacervata. See section on Germany.)

Allen and Wimbledon, 1991. regarding the Serpulite of Germany. See full references under correlation.

Andrews, J.E. 1986. Tube-like microproblematica as environmental and stratigraphic indicators in British Jurassic lagoonal deposits. Palaios, 1986, v.1, 85-86. Worm burrow linings of a stromatolitic mudflat community?

House, M.R. 1968. Purbeckian calcareous algae. In Dorset Natural History Reports - 1967 - Geology. Proceedings of Dorset Natural Hist Arch Society for 1967. vol. 89, p.41-45.

Slumps, Soft Sediment Deformation, Liquifaction

Ensom, P.C. 1984b. A syn-sedimentary slump and folds in the Purbeck Limestone Formation at Worbarrow Tout. Proceedings of Dorset Natural History and Archaeological Society, 105, 168.

Millson , J.A. et al. 1966. The Lower Palaeozoic of Omman and its context in the evolution of Gondwanan contintental margin. Journal of the Geological Society, London, 153, 213-230. Purbeck analogue. See p. 222, fig. 9a for ball and pillar structure and flame structure resembling Purbeck Unio Beds at Lulworth.

Solnhofen Limestone - Analogy

Barthel, K.W., Swinburne, N.H.M. and Morris, S.C. 1990. Solnhofen: a Study in Mesozoic Palaeontology. Cambridge University Press, Cambridge, 236 p. 733 BAR. ISBN - 0 521 33344 X Hardback. Originally published in German as " Solnhofen: Ein Blsick in die Erdgeschichte" by Ott Verlag. Thun 1978. The English edition is revised by the English authors. P. 59 - 60 -Preservation of insects in salt-rich sediment - Death Valley, California. " "Pickling" in salt solutions is an effective method of culinary preservation, because many of the decomposing microbes are inactivated and the decay process greatly slowed. In natural hypersaline environments sthere are documented cases of exceptionally slow organic decay which has resulted in special preservation of organisms. For example, in the extremely hot environment of Death Valley, California, there are examples of exquisite preservation of insects in the salt-rich sediment (W. Berger, pers. comm. 1989)." " The analogy between these extremely salty environments and the Solnhofen lagoonal basins cannot be carried very far, because salt concentrations in the (p. 60) Solnhofen water never reached very high values and the evaporating lagoonal waters must have been constantly diluted by an influx of normal marine water. Certainly the level of saturation of the lagoonal waters nearly always remained below the level of saturation with respect to the common dissolved salts, as there are no evaporitic beds in the plattenkalk sequences. ---. Sometimes the traces of salt crystals, long since dissolved away and infilled by calcite (making salt pseudomorphs) are found on bedding planes, but they probably did not form on the lagoon floor and attest only to local conditions within the sediment." Anoxia major preservation factor, moderate hypersalinity secondary. Some coccoliths more tolerant of high salinity. No logs found. Plant remains include cycadophytes, ginkgos, Araucaria, Palaeocyparis etc. Low organic matter. Insects, lacewings, beetles, water-scorpions,.

Spain

Hoedemaeker, P.J. and Leereveld, H. 1995. Biostratigraphy and sequence stratigraphy of the Berriasian-lowest Aptian (lower cretaceous) of the rio-argos succession, Caravaca, SE Spain. Cretaceous Research, 16: (2-3) 195-230 April-June, 1995. Abstract: Results of an interdisciplinary stratigraphical study of the Berriasian to lowest Aptian (Lower Cretaceous) succession in the Subbetic Zone of the Betic Cordillera (S Spain) are presented. The pelagic succession is exposed in a nearly continuous outcrop section along the Rio Argos and its tributaries west of Caravaca (SE Spain). Detailed lithologic columns are given as well as a brief description of the lithology. The boundary stratotypes of the two uppermost Hauterivian and one uppermost Berriasian ammonite chronosubzones are formally proposed here. The biozones of dinoflagellate cysts, calpionellids, nannofossils, and planktonic foraminifera are calibrated against the standard ammonite zonation for the Tethyan Lower Cretaceous. The depositional sequences are delimited and after comparison with the global sea-level chart several additional sequences are identified. The combination of standard ammonite biochronozones and depositional sequences enables precise chronostratigraphic calibration of other biozones and thus provides a firm chronostratigraphic framework for global correlation.

Jimenez de Cisneros, C. and Vera, J.A. 1993. Milankovitch cyclicity in Purbeck peritidal limestones of the Prebetic (Berriasian, southern Spain). Sedimentology, 40, No. 3, June, 1993, pp 513-539. Milankovitch cycles found by Fast Fourier Transform. Role of glacio-eustasy - see also Frakes and Francis 1988, Nature. (Cyclic carbonate deposition. Sierra del Pozo region, southeast Spain, near the coast, north-east of Granada. Black pebbles. Evaporites. Birdseyes. Del 13C and del 18 O isotope data. Sr ppm. Sr high in subtidal facies. Sedimentation rate 12-15 cm per 1000 yrs (ie. about 0.13 mm per annum).)

Platt, N.H. 1991. Lacustrine carbonates and pedogenesis: sedimentology and origin of palustrine deposits from the Early Cretaceous Rupelo Formation, W. Cameros Basin, N. Spain. Reprinted from Sedimentology, 1989, 665-684. Pages 323-342 in : Wright, V.P. and Tucker, M.E. 1991. Calcretes. International Association of Sedimentologists, Reprint Series, 2, 352. Blackwell Scientific Publications. Oxford. (Charophytes, ostracods, gastropods and rare vertebrates. Silicified evaporites found near the top of the sequence. Stable isotope analysis. del 13C for -7 to -11 and del 18 O from -3 to -7.5. Palustrine limestones formed through pedogenic modification of lake carbonate. Low gradient, low energy, unstratified lake. Berriasian. Dark intraclasts like black pebbles.)

Platt, N.H. and Pujalte, V. 1994. Correlation of Upper Jurassic - Lower Cretaceous continental sequences from the southern Biscay margin, northern Spain. Journal of the Geological Society, London, 151, 715-726.
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Rat , P. 1957. Carte Geologique des Pays Basco-Cantabriques entre St. Sebastian et Santander. [A coloured - Geological map of the Basque - Cantabrian country between Saint Sebastian and Santader, northwestern Spain.] 1:200,000. [This shows the Purbeckian and Valanginian near Ramales, southeast of Santander. The author states that "near Ramales, a series of calcareous-sandy strata lies above the Callovian. They contain beds with ostracods, serpulids and spirocyclinas, and correspond to the Purbeckien."]

Rat, P. 1960. Sur l'age at la nature des couches de base du Wealdien dans la province de Santander et a ses abords (Espagne). [On the age and nature of the beds at the base of the Wealden in the province of Santander and its surround (Spain).] Comptes Rendus des Seances de l'Academie des Sciences, France, t. 251, pp. 2207-2209. [Extract: 1. To the southeasst of Santander, near Ramales, the sandy clay complex does not rest directly on the marine Jurassic. It is effectively separated from the Callovian with Macrocephalites by: a. About 150m of dark brackish beds, limestones or sandy marls, with serpulids, spirocylinas and ostracods (Macrodentina, Cypridea) which he has compared to the Serpulite of Germany and the Purbeckian of England...."

Rat, P. 1962. Contribution a l'etude stratigraphiques du Purbeckien-Wealdien de la region de Santander (Espagne). [Contribution to the stratigraphic study of the Purbeckian-Wealden of the region of Santander (Spain)]. Bulletin de la Societe Geologique de France, 7th Series, tome 4, pp. 3-12. By Pierre Rat. Abstract: The strata, traditionally named Wealden in the Santander part of the Cantabrian Mountains comprises in reality: 1. a lower sequence partly lacustrine, partly brackish, which rests on the marine Callovian and has fossils such as ostracods and Iberina which lead one to compare it both by age and facies with the Purbeckian. The upper sequence, or Wealden in the strict sense, rarely rests directly on the Callovian. Towards the northwest is the Urgonian Complex. [Graphic logs, charophytes, ostracod photographs, Dictyocythere, and a correlation diagram showing the relationship to the Dorset strata.]

Rat, P. 1963. A propos du Wealdien cantabrique; transgression et regressions marine climatique. Note de M. Pierre Rat, presentee by M. Pierre Pruvost. [On the Cantabrian Wealden (including Purbeck); marine transgressions and regressions of climatic origin.] Comptes Rendus Academie des Sciences, France, tome 256, pp. 455-457. Seance du Janvier 1963. [Discusses the effect of changes in the rainfall regime, such as an increase in rainfall as producing a seaward movement of the freshwater facies, and thus an apparent regression. With a diagram of this.]

Rat, P. 1963. Problemes du Cretace Inferieur dans les Pyrenees et le Nord de l'Espagne. [Problems of the Lower Cretaceous in the Pyrenees and the north of Spain.] Sonderdruck aus der Geologischen Rundshau, Band 53, pp. 205-220. Abstract: Through recent publications, the major facts or new trends in the stratigraphy of lower Cretaceous are examined. A considerable extension of emerged areas marks the Upper Jurassic (Post-Callovian). A new paleogeography is thus starting. Henceforth terrigenous deposits (clay and sand) are almost continuously conflicting with a mostly calcareous marine sedimentation. The former are highly dependent on local conditions; the latter, unchanging over long periods in all the Mediterranean areas, is the result of really uniform geographical factors: e.g. Rudist limestones, Orbitolina series. In the course of time, a rather quiet but varied sedimentation (lacustrian, brackish or even marine) precedes, in different places, the dumping of huge quantities of "Wealden" sandstones. Elsewhere the discovery of marine Neocomian changes our views on the Aptian transgression. Lastly the detrital albian occurrence of Utrillas beds seems to be widely spread. A climatic change might be responsible for it.

Rat, P. and Salomon, J. 1966. Donnes nouvelles sur la stratigraphie et les variations sedimentaires de la serie purbecko-wealdienne au S de Santander (Espagne). By Pierre Rat and Jean Salomon. [New observations on the stratigraphy and the sedimentary variations of the Purbeck-Wealden Series to the south of Santander, Spain.]. Journal not known, pp. 216-217, 16 June, 1966. [Beds with the pellet Favreina and ostracods.]

Vera, J.A. and Jimenez de Cisnero, C. 1993. Palaeogeographic significance of black pebbles (Lower Cretaceous, Prebetic, southern Spain. Palaeo, Palaeo, Palaeo, 102, 89-102.

Wright, V.P. and Tucker, M.E. (1991) Calcretes. International Association of Sedimentologists, Reprint Series, 2, 352. Blackwell Scientific Publications. Oxford. QE 471 (See Calcretes: An Introduction - p. 1-22. Includes Klappa, C.F. 1991. Biolithogenesis of Microcodium: elucidation (reprint of 1978 paper). Includes: Platt, N.H. 1991. Lacustrine carbonates and pedogenesis: sedimentology and origin of palustrine deposits from the Early Cretaceous Rupelo Formation, W. Cameros Basin, N. Spain. Reprinted from Sedimentology, 1989, 665-684. Pages 323-342 in the book.)

Sphalerite, Zinc Blende

Weiner, J.S. 1955. The Piltdown Forgery. Oxford University Press, London, 214p. 882 P.7. Charles Dawson is blamed. Piltdown - Sussex, near River Ouse. Dawson reported zinc blende from the Wealden and Purbeck beds and in 1898 made an important discovery of natural gas at Heathfield ( used to light the hotel and station for many years). See p. 85.

Spiders

Selden, P.A. 1990. Lower Cretaceous spiders from the Sierra de Montsech, north-east Spain. Palaeontology, 33, 257-285.

Stromatolites

See also - algae
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Perry, C.T. 1994. Fresh-water tufa stromatolites in the basal Purbeck Formation (Upper Jurassic), Isle-of-Portland, Dorset. Geological Journal, 29, 119-135. Abstract: Recent interpretations of the tufaceous limestones from within the 'Caps Beds' on the Isle of Portland have suggested a depositional environment of intertidal flats and lagoons with typically higher than normal marine salinity levels, a stark contrast with earlier ideas of a freshwater origin. However, evidence is presented in this paper to show that these deposits are indeed most likely to be freshwater in origin. The micro-fabrics observed are typical of those seen in freshwater tufas forming at the present day, and contrast with those observed within intertidal/subtidal stromatolites. Furthermore, the Portland deposits lack syndepositional evaporite deposits, they lack recognizable intertidal deposits, and any lagoonal sediments observed are depositionally distinct from the tufas. Finally, the soil horizons observed are clear evidence of periodic subaerial exposure and isolation from marine influences. Four facies types are identified on Portland: (1) tufaceous limestone; (2) littoral grainstones; (3) subaerial stromatolites; and (4) paleosols. Each facies is repeated a number of times through the sequence, and evidence is presented to show that these formed in a marginal marine setting as a response to a series of minor transgressive (soils to freshwater lakes/lagoon to saline marine/lagoonal) and regressive events (saline marine/lagoonal to soils). The tufa stromatolite deposits themselves, which are often developed around cylindrical holes (representing former tree trunks and branches), are shown to have developed seasonally, by the precipitation of carbonate, due to microbial activity within the freshwater lake environment. Precipitation appears to have been most intense around tree bases (and any associated vegetation), where an active biofilm developed on the underlying soil substrate. Two distinct textures are recognized in this material: (1) micro-porous and (2) macro-porous. These developed together in a crudely laminated, semi-concentric pattern around the holes and together may represent a seasons growth of tufa. [This paper is particularly useful in providing detailed description and showing the unusual features of the Purbeck stromatolites. The present writer considers that the lack of a freshwater gastropod fauna, lack of low salinity ostracods, and the presence of pseudomorphs after gypsum in the equivalent strata (the Hard Cap) with stromatolites at the Fossil Forest is evidence against a freshwater origin. See West (1975) for details of high salinity evidence. ]

Structures and Tectonics - re Purbeck

Phillips, W.J. 1964. Structures in the Jurassic and Cretaceous rocks on the Dorset coast between White Nothe and Mupe Bay. Proceedings of the Geologists' Association, 75, 373-405.

Sussex (Weald Area)

Feist, M., Lake, R.D. and Wood, C.J. 1995. Charophyte biostratigraphy of the Purbeck and Wealden of southern England. Palaeontology, 38, 407-442. Purbeck and Wealden charophytes, mostly from the Weald area. A new set of charophte zones. Lowest is Globator rectispirale. Clavator westii is considered and said to be indeterminate. No reference to West - Swindon facies note or other west paper. The Jurassic Cretaceous boundary is located within the Lulworth Formation.

Holliday, D.W. and Shephard-Thorn, E.R. 1974. Basal Purbeck evaporites of the Fairlight Borehole, Sussex. Institute of Geological Sciences, Report No. 74/4.

Holliday, D.W. 1973. Early diagenesis in nodular anhydrite rocks. Transactions of the Institute Min. Metall., 82, B81-4.

Howitt, F. 1964. Stratigraphy and structure of the Purbeck inliers of Sussex (England). Quarterly Journal of the sG Geological Society of London., 120, 77-113.

Lake, R.D. and Shephard-Thorn, E.R. 1988. Wealden and Purbeck Beds strata exposed in cliff sections, surface exposures and undground workings in the Hastings-Dungeness dst.(shts 320/321), wth an account of the sea-bed geology east of Dungeness. 99pp., British Geological Survey Technical Report Onshore Geological Series. WA/88/6.

Lister J. K. and Batten, D.J. 1988. Stratigraphic and palaeoenvironmental distribution of Early Cretaceous dinoflagellate cysts in the Hurlands Farm Borehole, West Sussex, England. Palaeontogr., abt. b., stuttgart, 1988, 210 (1-3) 9-89 Bundesanstalt fuer Geowissenschaften Rohstoffe (BGR, Federal Republic of Germany)

Milner, H.B. 1922. The Geology of the Country around Heathfield, Sussex. Proceedings of the Geologists' Association, 33, p. 142 - . Oil shale in the Purbecks.

Ruffell, A., Ross, A. and Taylor, K. 1996. Early Cretaceous environments of the Weald. Edited by J.T. Greensmith. Geologists' Association Guide No. 55. .

Woodward, H.B. 1895. The Jurassic Rocks of Britain. Vol 5. The Middle and Upper Oolitic Rocks of England (Yorkshire excepted). Memoirs of the Geological Survey of the United Kingdom. 499pp.

Swanage - Quarries and Town

Regarding Purbecks

Brannon, P. 1859. Illustrated historical and picturesque guide to Swanage and the Isle of Purbeck. R. Sydenham, Poole: Longman and Co., London.

Braye, J. 1890. Swanage (Isle of Purbeck): Its History, Resources as an Invigorating Health Resort, Botany and Geology. 2nd Edition. William Henry Everett and Son, Salisbury Square, Fleet Street, London, 119 pp. (John Bray). Price One Shilling. Introduction by L. Forbes Winslow, Physician to the North London Hospital for Consumption. Extract - " Swanage is happily placed with regard to good stone and marble, the Purbeck stone having been used for ages in paving the streets of London, and by the Government in military works at Portsmouth, Dover, and elsewhere. Certainly this should be sufficient guarantee of its durability and suitability for building a substantial town for the future generations. The minor question of cost should not not be an insurmountable obstacle. - If a gentleman wants a coat he goes to Savile Row or Bond Street - a working man finds his way to Hounditch. -- Much is said in the present day about sanitary buildings, but little of the foolish vagaries of those inflated gentlemen the architects, who have managed to spoil many of our pleasure places by putting up shoddy buildings of lath and plaster, and ticketing them with fantastic names such as "Bungalow". -- Such buildings are well suited to stand a few years in the tropics; but utterly worthless for a decent watering place, and the builders who errect them should be prosecuted for tempting frivolous and thoughtless pleasure-seekers to risk their lives in them." (and more in this style!). ---- Geology chapter by Horace B. Woodward, F.G.S. pp 63-82. Extract: "The Purbeck Beds mark changing conditions; freshwater limestones, botryoidal and tufaceous in character, like beds of travertine, are succeeded in places by evidences of land vegetation in the now silicified remains of Cycads and Conifers. The beds indicate that after the freshwater and terrestrial conditions, which may have been marked by a lake or a series of lagoons, a sudden irruption of the sea in Middle Purbeck times allowed the incursion of marine forms like the Pecten, Avicula, and Hemicidaris. These were succeeded by a gradual change from brackish to freshwater conditions in Upper Purbeck times, when the Unio, Physa, Valvata, Paludina, and Planorbis flourished. " (a good geological account, but note that, with modern knowledge, we now know that not all the points made in the extract are correct).

Hardy, W.M. 1908. Old Swanage, or Purbeck Past and Present. Dorset County Chronicle, Dorchester.

Legg, R. Old Swanage.

Legg, R. 1989. Purbeck Island: the industrial, social and natural history of a corner of England. (2nd Revised Edition 1989, first published 1972). Dorset Publishing Company at the Wincanton Press. 230 pp. With interesting details of stone quarrying and old illustrations.

Lewer, D. and Smale, D. 1994. Swanage Past. Phillimore and Co. Ltd, Chichester, West Sussex. 178 pp. ISBN 0 85033 949 9. This is a fascinating book with many old pictures of Swanage and its inhabitants. Recommended for anyone interested in the history of the area or the previous appearance of the coast.

Oppe, E.F. 1954. Through to Swanage. (A holiday guide pamphlet with geology). .

Swindon, Wiltshire

Unusual low salinity Lower Purbeck in the Town Gardens Quarry. Small exposures still remaining. Interesting fauna.

Allen, P. 1955. Age of the Wealden in N.W. Europe. Geol. Mag, 92, 265-281. Attempts to discredit Wolburg's (1949, 1950) view that the Wealden of the Weald is entirely Valanginian. Allen's evidence is weak but he might be right. Refers to the Swindon Wealden.

Allen, P. and Wimbledon, W.A. 1991. Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas. Cretaceous Research, 12, 511-526. . Mention of German invertebrates at Swindon.

Hudleston, W.H. 1876. Excursion to Swindon and Farringdon. Proceedings of the Geologists' Association, 4, 543-554. Unconfirmed report of a frog at Swindon.

West, I.M. 1961. Lower Purbeck Beds of Swindon facies in Dorset. Nature London, 190, 526.

Sylvester Bradley, P.C. 1940. The Purbeck beds of Swindon. Proceedings of the Geologists' Association, London, 51, 349-372.

Thicknesses of the Purbeck Formation

Chadwick, 1975. In Whittaker - see below.

Chilworth Borehole Log. Chilworth No.1. 110 feet. Limestones on 30 feet of anhydrite. Unpublished.

Hoe Borehole Log. Hoe No.1. 104 feet. Limestones on 15 feet of anhydrite. Unpublished.

Whittaker, A. 1985. Atlas of Onshore Sedimentary Basins in England and Wales. Post-Carboniferous Tectonics and Stratigraphy. British Geological Survey, Blackie, Glasgow, 7lpp. Many folded maps. Includes a map of the Purbeck and Wealden thicknesses and depth to Purbeck anhydrite. Includes short paper by Chadwick - Early Jurassic to .... Late Portlandian ... Barremian ..... etc.

Trace Fossils

Radley, J.D. in press 1997. Phoronid worm borings from the Middle Purbeck Beds (Lower Cretaceous) of Swanage, Dorset. Proceedings of Dorset Natural History and Archaeological Society. (An isolated oyster shell - Praeexogyra cf. distorta displaying branching phonorid worm borings (Talpina sp ), has been found in a marl parting within a 0.75m thick biosparite, the " Red Rag ", bed DB 133 of Clements, 1993. The worm borings are absent from Neomiodon shells within the Red Rag, indicating that the oyster shell was infested prior to derivation. It may have been reworked from landward subfossil " terraces &and quot relating to earlier eustatic transgressive episodes (Wimbledon, 1987), rather than from contemporaneous basinward saline facies.

Trees Fossils

Go to Fossil Forest section

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Tufa - Analogues

See also Algae etc.

Pedley, H.M. 1987. The Flandrian (Quaternary) Caerwys Tufa, North Wales: an ancient barrage tufa deposit. Proceedings of Yorkshire Geological Society, 46, 141-152. Abstract: An extensive deposit of tufa, including organic build-ups, oncoid facies and micrite facies, extents as a lobate deposit downslope from a Carboniferous Limestone scarp near Caerwys, North Wales. The deposit contains terrestrial and freshwater molluscs, ostracods and plant remains, the latter now preserved as moulds and casts. Abstract continues.

Perry, C.T. 1994. Freshwater tufa stromatolites in the Lower Purbeck Beds (Upper Jurassic), Isle of Portland, Dorset. Geological Journal, 29, 1129-135. An abstract has been published as Perry, 1992. [Controversial.]

Turtles
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Anonymous. 1909. Fossil turtle excavated at Swanage. Dorchester and Sherborne Journal, 3.
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Lydekker, R. 1889. On certain chelonian remains from the Wealden and Purbeck. Quarterly Journal of the Geological Society, London, 45, 511-518.

Lydekker, R. and Boulenger, G.A. 1887. Notes on Chelonia from the Purbeck, Wealden and London Clay. Geological Magazine, (3), vol. 4, 270-275.

Upwey, Dorset

Old quarries north of Weymouth. Some sections are preserved. (see also Ridgeway)

Ensom, P. C. 1984a. A temporary exposure of the Purbeck Limestone Formation (Upper Purbeck Beds) at Friar Waddon Pumping Station, Dorset. Proceedings of Dorset Natural History and Archaeological Society, 105, 89-91.

Fisher, O. 1856. On the Purbeck strata of Dorsetshire. Transactions of the Cambridge Philosophic Society, 9, 555-581.

Whitaker, W. and Edwards, W. 1926. Wells and Springs of Dorset. Memoirs of the Geological Survey. 119 + xi pages. See Friar Waddon borehole, p. 74.

Westhead, R.K. 1992. Geology of the Dorchester (South) District (Dorset). 1:10,000 Sheet SY NE. British Geological Survey Technical Report WA/93/22. (Also includes part of 1:50,000 Sheet 328 Dorchester, 327 Bridport and 341/342 Weymouth). . Not in (Sept 93). Mapping by Westhead. Logging of Purbeck Group pits was undertaken by A.E. Mather (Plymouth University), who also provided sedimentological information. Purbeck succession divided into (from base) Windsbatch Limestone Mb, Bincombe Mb, Ridgeway Mb, Bayard Hill Limestone Mb and at top Friar Waddon Member. Named chalk subdivisions for the Dorchester area are given. The new terminology is a simplification that is probaly not justified except for the purposes of mapping.

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Wardour, Vale of Wardour

Andrews, and Jukes-Browne, 1894. Quarterly Journal of the Geological Society, London, vol. 1, p.52 -

Astin, T.R. 1987. Petrology (including fluorescence microscopy) of cherts from the Portlandian of Wiltshire, U.K. - evidence of an episode of meteoric water circulation. Pp. 73-85 in Marshall, J.D. Diagenesis of Sedimentary Sequences. Geological Society Special Publication No. 36, 73-85. [Some carbonate grain dissolution prior to silicification. Chicksgrove Plant Bed. Wockley Member. Wardour.]

Benett, E. 1831. A Catalogue of the Fossil Organic Remains of the County of Wiltshire. Warminster: J.L. Vardy, ix + 9 pp.

Brodie, P.B. 1845. A History of Fossil Insects in the Secondary Rocks of England. accompanied by a particular account of the strata in which they occur , and of the circumstances connected with their preservation. John Van Voorst, London, 130pp.

Curry, D. and Wisden, D.E. 1958. Geology of the Southampton Area. Geologists' Association, Guide, Colchester. [Mention of Vale of Wardour Purbeck localities.]

Hester, S.W. 1958. An unrecorded section in the Purbeck of the Vale of Wardour. Proceedings of the Geologists' Association, London., 49, 20 - 22. Laevitrigonia gibbosa is present in the Cinder Bed.

Milne-Edwards, H. 1843. Note sur deux Crustaces fossiles de l'Ordre des Isopodes. (Archaeoniscus Brodiei) . Annales of Science Naturelles, ser. 2, vol 20, p. 323 see also Idem 1844 vol 18, p.110
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Ord , T. and Reader, T.W. 1912. Report on an excursion to Dinton, Chilmark and the Vale of Wardour. Proceedings of the Geologists' Association, 23, 148-157. Teffont Evias, Chilmark Ravine, Beekite on Portland shells, geological map, Cinder Bed, fish, silicified trees, Turtle, Trigonia desinodosa in the Cinder Bed. Portland succession in well at Teffont Quarry, Chilmark. Useful photographs. Karstic features in Purbeck limestone (like clints and grikes) at Ladydown near Tisbury (photo).

Reid, C. 1903. The Geology of the Country around Salisbury (explanation of sheet 298), Memoirs of the Geological Survey, H.M. Stationery Office , London, 77pp. (Vale of Wardour Purbeck)

Woodward, H.B. 1895. The Jurassic Rocks of Britain. Vol 5. The Middle and Upper Oolitic Rocks of England (Yorkshire excepted). Memoirs of the Geological Survey of the United Kingdom. 499pp. and

Worbarrow Bay, Dorset
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Arkell , W.J. 1940. Dorset Geology, 1930-1940. Proceedings of Dorset Natural History Archaeological Society, 61, 117-135.
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Ensom , P. C. 1985. An annotated section of the Purbeck Limestone Formation at Worbarrow Tout, Dorset. Proceedings of Dorset Natural History and Archaeological Society, 106, 87-91.