The BGS Lexicon of Named Rock Units — Result Details

Shepherd's Chine Member

Computer Code: SHCH Preferred Map Code: notEntered
Status Code: Full
Age range: Barremian Age (KB) — Aptian Age (KP)
Lithological Description: Pale to dark grey fine-grained sandstones, siltstones and mudstones rhythmically-bedded in up to 65 thin fining-upward units. Each unit comprises a pale grey fine-grained sandstone or siltstone with a sharp and erosional contact at the base, passing up into dark grey mudstone. Several thin muddy limestones comprising bivalve and other shell concentrates occur in the higher parts of the succession together with a "beef-bed" (see sections in Osborne White, 1921).
Definition of Lower Boundary: Conformable at a sharp but irregular contact between medium-grained sandstone (or mudstone/bivalve conglomerate) of the Barnes High Sandstone Member up into rhythmically-bedded fine-grained sandstones, siltstones and mudstones of the Member.
Definition of Upper Boundary: At the change from grey mudstones with an eroded and burrowed upper surface in contact with the basal dark green to greyish green, glauconitic, very shelly sandstone of the Perna Bed Member (Insole et al., 1998) of the Atherfield Clay Formation. This boundary is generally some 4-5 m above a distinctive shelly limestone associated with a "Beef-Bed" (fibrous calcite commonly showing cone-in-cone structures).
Thickness: c.50m on the Isle of Wight.
Geographical Limits: Limited to the Isle of Wight.
Parent Unit: Vectis Formation (VTIS)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Compton Bay, west of Shippard's Chine [SZ 3750 8440]. Where the full succession is visible but frequently confused by landslides. 
Reference Section  Sandown Bay, Isle of Wight from the Yaverland [SZ 6150 8514] to Red Cliff [SZ 6209 8532]. Where a thin succession of the member is visible. 
Type Section  Brighstone Bay, Isle of Wight, from Atherfield Point [SZ 452 791] northwestward towards Barnes Chine [SZ 435 808]. 
Reference(s):
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.] 
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. 
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. 
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. 
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