| Computer Code: |
BAC |
Preferred Map Code: |
BaC |
| Status Code: |
Full |
| Age range: |
Lutetian Age (GL)
— Bartonian Age (GB) |
| Lithological Description: |
Olive grey and greenish grey shelly clays of varying sand content. Fine-grained clayey, commonly glauconitic, sands and flint pebble beds occur in the lower part of the sequence. Shelly in parts. |
| Definition of Lower Boundary: |
Lower boundary is marked by a bed of flint pebbles and the incoming of glauconitic sandy clays above both fine-to medium-grained sands of the Selsey Sand Formation in the east or the Boscombe Sand Formation in the west; both of the Bracklesham Group. This boundary is an interburrowed omission surface which marks a regional unconformity (Todd, 1990). |
| Definition of Upper Boundary: |
Overlain everywhere across its range by the Chama Sand Formation of the Barton Group at an abrupt upward change from silty clay to coarser-grained sediments. |
| Thickness: |
Between 38m and 83m. |
| Geographical Limits: |
Preserved over a wide area of the central Hampshire basin, S. England. |
| Parent Unit: |
Barton Group (BA)
|
| Previous Name(s): |
Barton Clay [Obsolete Name and Code: Use BAC]
(-1324)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Cliffs between Highcliff Castle and Barton-on-Sea where up to 40 m of glauconitic sandy clay are seen intermitently in mainly obscured exposures. Edwards and Freshney (1987). |
| Type Section |
Type section of Elmore Member at Whitecliff Bay Isle of Wight. Gale et al. (1999). |
| Reference(s): |
| Edwards, R A, and Freshney, E C. 1987. Lithostratigraphical classification of the Hampshire Basin Palaeogene Deposits (Reading Formation to Headon Formation) Tertiary Research, Vol. 8, 43-73. |
| White, H J O. 1917. Geology of the country around Bournemouth (2nd edition). Memoir of the Geological Survey of Great Britain, Sheet 329 (England and Wales). |
| Bristow, C R, Freshney, E C, and Penn, I E. 1991. Geology of the country around Bournemouth. Memoir for 1:50 000 geological sheet 329 (England and Wales). HMSO, London. |
| 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). |
| Curry, D, Adams, C G, Boulter, M C, Dilley, F C, Eames, F E, Funnell, B M, and Wells, M K. 1978. A Correlation of Tertiary rocks in the British Isles. Geological Society of London Special Publication, Vol. 12, 1-72. |
| Gale, A S, Jeffery, P A, Huggett, J M, and Connolly, P. 1999. Eocene inversion history of the Sandown Pericline, Isle of Wight, southern England. Journal of the Geological Society of London, Vol. 156, 327-339. |
| Daley, B, and Balson, P. 1999. British Tertiary Stratigraphy. Geological Conservation Review Series Volume 15 Peterborough. (Joint Nature Conservation Committee) |
| Todd, J. 1990. The stratigraphy and correlation of the Selsey Formation and Barton Clay Formation (Middle Eocene) of Studley Wood, Hampshire. Tertiary Research, Vol. 12, 37-50. |
| Stinton, F C. 1975. Fish otoliths from the English Eocene. No. 1. (Palaeontological Society Monograph.) |
| Kemp, D J, King, A, King, C, and Quayle, W J. 1979. Stratigraphy and biota of the Elmore Formation (Huntingbridge Division, Bracklesham Group) at Lee-on-the-Solent, Hampshire. Tertiary Research, Vol. 2, 93-103. |
| Edwards, R A, and Freshney, E C. 1987. Geology of the country around Southampton. Memoir of the British Geological Survey, Sheet 315 (England and Wales). |
| Gardner, J S, Keeping, H, and Monckton, H W. 1988. The Upper Eocene, comprising the Barton and Upper Bagshot Formations. Quarterly Journal of the Geological Society, Vol. 44, 578-635. |
| King, C. In press. A correlation of Tertiary rocks in the British Isle and adjacent areas. Special Report of the Geological Society of London, No.12. |
| Hooker, J J. 1975. Reports of a field meeting to Hengistbury Head and adjacent areas, Dorset, with an account of published work and some new exposures. Tertiary Times, Vol.2, 109-121. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E314
E315
E329
E330
|
