The BGS Lexicon of Named Rock Units — Result Details

Little Wenlock Basalt Member

Computer Code: LWKB Preferred Map Code: LWB
Status Code: Full
Age range: Brigantian Substage (CX) — Brigantian Substage (CX)
Lithological Description: Microporphyritic olivine-basalt lava.
Definition of Lower Boundary: Geological log of the Dinantian sequence at Lilleshall (Bridge and Hough, 2002) shows a sharp junction between basalt overlying limestone (formerly 'Lower Limestone') of the Sylvan Limestone Formation.
Definition of Upper Boundary: The basalt is overlain by sandstone, limestone or mudstone (formerly 'Upper Limestone') of the Sylvan Limestone Formation. The upper part of the Little Wenlock Basalt is locally marked by a weathered bole.
Thickness: 25 to 60m in the Little Wenlock area.
Geographical Limits: Little Wenlock, [SJ6470 0700], Lilleshall [SJ73 15] and Coalbrookdale [SJ64 08].
Parent Unit: Sylvan Limestone Formation (SYLV)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Numerous bedrock and stream sections in the Little Wenlock area, Shropshire . See principal reference for details of exposures. 
Reference Section  Doseley Quarry. 
Reference(s):
Hamblin, R J O and Coppack, B C, 1995. Geology of Telford and the Coalbrookdale Coalfield. Memoir of the British Geological Survey, parts of Sheets 152 and 153 (England and Wales). 
Pocock R W, Whitehead T H, Wedd C B and Robertson T. 1938. Shrewsbury District including the Hanwood Coalfield. Memoir of the Geological Survey of Great Britain, England and Wales. (London: H.M.S.O.). 
Bridge, D M and Hough E, 2002. Geology of the Wolverhampton and Telford district. Sheet Description of the BGS Sheet 153 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable