The BGS Lexicon of Named Rock Units — Result Details

London Fields Basalt Sill

Computer Code: LFSI Preferred Map Code: LFS
Status Code: Full
Age range: Bolsovian Substage (CC) — Bolsovian Substage (CC)
Lithological Description: Micro-ophitic olivine basalt and porphyritic microgabbro (dolerite).
Definition of Lower Boundary: Sharp boundary with either unaltered mudstone or coal of the Pennine Coal Measures Group.
Definition of Upper Boundary: Sharp boundary with either unaltered mudstone or coal of the Pennine Coal Measures Group.
Thickness: Up to 22 m thick, as proved in the Russell’s Hall No.19 Pit (SO99SW/71) [SO 9322 9028].
Geographical Limits: Outcrops at Sandfield Bridge [SO 980 906], Cooper’s Bank [SO 918 904], Dibdale [SO 920 906; SO 929 905], London Fields [SO 929 905; SO 931 907] and Dudley [SO 946 898].
Parent Unit: Dudley Basaltic Sill-and-vent-swarm (DUDB)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  London Fields near Dudley. No exposures described and proved in old borehole and shaft records. Described but not named by Whitehead and Pocock (1947). 
Reference(s):
Whitehead, T H and Pocock, R W. 1947. Geology of the country around Dudley and Bridgnorth. Memoir of the British Geological Survey, Sheet 167. (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E167