The BGS Lexicon of Named Rock Units — Result Details

Croft Member

Computer Code: CRFT Preferred Map Code: uc
Status Code: Pending Upgrade
Age range: Merioneth Series (EM) — Merioneth Series (EM)
Lithological Description: Black, fissile, mudstone interlaminated with micaceous siltstone and very fine-grained sandstone.
Definition of Lower Boundary: Base of mudstone of above type, resting unconformably on shelly glauconitic limestone of the Lower Comley Limestones.
Definition of Upper Boundary: Not proved.
Thickness: 53.75m
Geographical Limits: Lilleshall Inlier, Shropshire.
Parent Unit: Bentleyford Shales Formation (BTS)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Croft Borehole, Lilleshall, SJ71NW/16. 
Rushton, A W A, Hamblin, R J O and Strong, G E, 1988. The Croft Borehole in the Lilleshall Inlier of North Shropshire. Report of the British Geological Survey, Vol.19, No.3. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable