| 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): |
| 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.). |
| 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). |
| 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 |
