The BGS Lexicon of Named Rock Units — Result Details

Cowleaze Chine Member

Computer Code: CCH Preferred Map Code: notEntered
Status Code: Full
Age range: Barremian Age (KB) — Barremian Age (KB)
Lithological Description: The member comprises finely interlaminated dark grey mudstone and pale grey silt/fine-grained sandstone. In places arranged into thin fining-upwards units. The mudstones are intensely bioturbated. In some areas a 1m-thick white fine-grained sandstone (the White Rock) occurs at the base.
Definition of Lower Boundary: The base is conformable and marked by an abrupt upward colour change from the bright (usually red tinged) friable sandstones and calcareous mudstones of the Wessex Formation below up into the dark grey and pale grey mudstones of the member. In places a bone-bed marks this boundary (the "Hypsilophodon Bed") as described in the Isle of Wight Memoir (Osborne White, 1921).
Definition of Upper Boundary: The upper boundary is conformable at a variable upward change from grey mudstones of the member below into medium-grained yellow sandstone of the Barnes High Sandstone Member above. In places the boundary is abrupt and in others gradational. The boundary is defined at the base of the first up-succession medium-grained yellow sandstone of the Barnes High Sandstone Member, whether this is in the form of a continuous bed or a discontinuous lenticular layer (Insole et al., 1998).
Thickness: 7 to 10m.
Geographical Limits: Only known from the Isle of Wight.
Parent Unit: Vectis Formation (VTIS)
Previous Name(s): none recorded or not applicable
Alternative Name(s): Part Of The Wealden Shales
Stratotypes:
Reference Section  Compton Bay, west of Shippard's Chine [SZ 3750 8440]. About 7m of the member is seen in low cliffs. 
Type Section  West of Cowleaze Chine, [SZ 4426 8013] Brightstone Bay, Isle of Wight specifically from Barnes High [SZ 4373 8070] to just west of Shepherd's Chine [SZ 4462 7988]. Where the full 8.0m of the member is visible in the low cliffs. 
Reference Section  Sandown Bay, Red Cliff, Isle of Wight, from [SZ 6178 8526] eastward. About 10m of the member is poorly exposed in low degraded cliffs north of Yaverland Car Park. 
Reference(s):
Daley, B and Stewart, D J. 1979. Weekend field meeting: The Wealden Group in the Isle of Wight. Proceedings of the Geologists' Association, Vol.90, 51-54. 
Kerth, M and Hailwood, E A. 1988. Magnetostratigraphy of the Lower Cretaceous Vectis Formation (Wealden Group) on the Isle of Wight, southern England. Journal of the Geological Society, Vol.145, 351-360. 
Osborne White, H J. 1921 [1994 reprint]. A short account of the geology of the Isle of Wight. Memoirs of the Geological Survey of Great Britain. 235pp. [HMSO.] 
Stewart, D J. 1981. A field guide to the Wealden Group of the Hastings area and the Isle of Wight. 3.1-3.32 in Elliott, T (Editor), Field Guides to Modern and Ancient Fluvial Systems in Britain and Spain, International Fluvial Conference, Keele University, UK. 
Insole, A, Daley, B, and Gale, A. 1998. The Isle of Wight. Geologists’ Association Guide. No. 60. (The Geologists’ Association.)  
Arkell, W J. 1947. Geology of the country around Weymouth, Swanage, Corfe and Lulworth. Memoir of the British Geological Survey. Sheets 341, 342, 343 and small portions of sheets 327, 328 and 329 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable