The BGS Lexicon of Named Rock Units — Result Details

Eype Clay Member

Computer Code: EYCL Preferred Map Code: EyCl
Status Code: Full
Age range: Pliensbachian Age (JE) — Pliensbachian Age (JE)
Lithological Description: Pale grey, micaceous, variably silty mudstone with many small siderite nodules. At base, Three Tiers Sandstone, c.7m thick, consisting of three units each 0.5 to 1m thick of very fine-grained sandstone, separated by sandy shale.
Definition of Lower Boundary: Base of Three Tiers Sandstone. Sharp boundary on mudstone of Green Ammonite Member.
Definition of Upper Boundary: Base of Starfish Bed (Downcliff Sand Member).
Thickness: 60m
Geographical Limits: Southwest Dorset. Mapped on Sheet 327 (Bridport). Northern limit not yet proved.
Parent Unit: Dyrham Formation (DYS)
Previous Name(s): Margaritatus Marls (-3394)
Micaceous Beds (-3395)
Blue Clays (-239)
Eype Clay (-240)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Seacliffs between Seatown and Eype Mouth, Dorset. Howarth, M K, 1957. 
Reference(s):
Arkell W J, 1933. The Jurassic System in Great Britain [Oxford: Clarendon Press.] 
Howarth, M K, 1957. The Middle Lias of the Dorset coast. Quarterly Journal of the Geological Society of London, Vol.113, 185-204. 
Day, E C H, 1863. On the Middle and Upper Lias of the Dorsetshire Coast. Quarterly Journal of the Geological Society of London, Vol.19, 278-297. 
Lang, W D, 1913. The lower Pleinsbachian - 'Carixian' - of Charmouth. Geological Magazine, Vol.10, 401-412. 
Woodward, H B, 1893. The Jurassic rocks of Britain. 3. The Lias of England and Wales (Yorkshire excepted). Memoir of the Geological Survey of Great Britain. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E343 E326 E327