Computer Code: |
CR |
Preferred Map Code: |
Cr |
Status Code: |
Full |
Age range: |
Oxfordian Age (JO)
— Oxfordian Age (JO) |
Lithological Description: |
Complex succession of interdigitating limestones, marls, sandstones, sands, siltstones, silts, spiculites, mudstones. |
Definition of Lower Boundary: |
First appearance of medium- or coarse-grained sand above the Oxford Clay Formation. In some areas, this also defines the top of that Formation but elsewhere, there is an intervening silty unit (West Walton Formation). |
Definition of Upper Boundary: |
In the Dorset reference area, at the base of the Inconstans Bed (Kimmeridge Clay Formation), which also marks the Oxfordian-Kimmeridgian stage boundary, but elsewhere at the base of the thick mudstone succession that spans that stage boundary (ie Ampthill Clay and equivalents, and Kimmeridge Clay). |
Thickness: |
To c.100m |
Geographical Limits: |
Dorset to Oxfordshire, and North Yorkshire. |
Parent Unit: |
Not Applicable (-)
|
Previous Name(s): |
Corallian Formation [Obsolete Name and Code: Use CR]
(-160)
Corallian Beds
(-815)
Corallian Rocks
(-816)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Reference Section |
Howardian Hills, North Yorkshire (quarry and natural sections). |
Type Area |
Coast between Weymouth and Ringstead, Dorset, England |
Reference Section |
Coastal cliffs and foreshore between Weymouth and Ringstead Bay, Dorset. |
Reference Section |
Filey Brigg to the Hambleton Hills (inclusive), North Yorkshire (quarry and natural sections). |
Reference(s): |
Wright, J K. 1972. The stratigraphy of the Yorkshire Corallian. Proceedings of the Yorkshire Geological Society, Vol. 39, 225-266. |
Melville, R V and Freshney, E C. 1982. British Regional Geology: the Hampshire Basin and adjoining areas (4th Edition).(London ,HMSO for Institute of Geological Sciences). |
Sherlock, R L, 1960. London and Thames Valley. British Regional Geology. |
Arkell, W J. 1936. The Corallian Beds of Dorset, Part 1: The Coast. Proceedings of the Dorset Natural History and Archaeological Society, Vol. 57, 59-93. |
Sun, S Q, 1989. A new interpretation of the Corallian (Upper Jurassic) Cycles of the Dorset Coast, Southern England. Geological Journal, Vol 24, p. 139. |
Cope, J C W (editor). 1980b. A correlation of Jurassic rocks in the British Isles. Part Two: Middle and Upper Jurassic. Geological Society of London Special Report, No. 15 |
Hallam, A, 1975. Jurassic Environments, p.79,82-82,165. Cambridge. |
Arkell, W J. 1933. The Jurassic System in Great Britain (Oxford: Clarendon Press.) |
Fursich, F T. 1976. The use of macroinvertebrate associations in interpreting Corallian (Upper Jurassic) environments. Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 20, 235-256. |
Johnson, A L A, 1983. Field meeting on the Corallian of Oxfordshire, 16th May 1982. Proceedings of the Geologists' Association, Vol 94, P. 177. |
Wright, J K, 1981. The Corallian rocks of north Dorset. Proceedings of the Geologists' Association, Vol.92, 17-32. |
Horton, A, Sumbler, M G, Cox, B M and Ambrose, K, 1995. Geology of the country around Thame. Memoir of the British Geological Survey, Sheet 237 (England and Wales). |
Arkell, W J. 1927. The Corallian rocks of Oxford, Berkshire and north Wiltshire. Philosophical Transactions of the Royal Society of London, Vol. B216, 67-181. |
Wright, J K, 1980. Oxfordian Correlation Chart. "In" Cope, C J W, (Editor). A correlation of Jurassic rocks in the British Isles, Part two: Middle and Upper Jurassic. Geological Society of London Special Report No.15. (p.61-76 in Correlation Chart). |
Wright, J K. 1986. A new look at the stratigraphy, sedimentology and ammonite fauna of the Corallian Group (Oxfordian) of south Dorset. Proceedings of the Geologists' Association, Vol. 97, 1-21. |
Blake, J F, and Huddleston, W H. 1877. On the Corallian rocks of England. Quarterly Journal of the Geological Society of London, Vol. 33, 260-405. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E341
E342
E237
E313
E252
E052
E282
E327
E055
E065
E064
E158
E187
E188
E204
E220
E253
E254
E265
E266
E268
E281
E343
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