The BGS Lexicon of Named Rock Units — Result Details

Winstermoor Lava Member

Computer Code: WMB Preferred Map Code: WMB
Status Code: Full
Age range: Brigantian Substage (CX) — Brigantian Substage (CX)
Lithological Description: A dark grey basaltic lava, locally altered to green and brown clay with basalt fragments.
Definition of Lower Boundary: Basalt of the Winstermoor Lava Member rests upon pale grey, massive limestones of the Bee Low Limestone Formation.
Definition of Upper Boundary: The basalt of the Winstermoor Lava Member is overlain by grey to dark grey, bituminous limestones of the Monsal Dale Limestone Formation.
Thickness: Up to 4.4 m thick proved in the Aldwark Borehole.
Geographical Limits: Restricted to the area between Gratton Dale, Winster and Bonsall Moors and the workings of Millclose Mine. Boreholes show the lavas to be lenticular in distribution and locally absent.
Parent Unit: Monsal Dale Limestone Formation (MO)
Previous Name(s): Winstermoor Lava (-2538)
Winstermoor Basalt (-3765)
Winster Moor Lava (-1922)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Aldwark Borehole (SK25NW22), confidential record: 4.4 m thick clay with altered basalt fragments. Aitkenhead et al., 1985. 
Type Area  Sacheveral Farm: There are no exposures, but the member is recognised by lava fragments in the soil. Aitkenhead et al., 1985. 
Reference(s):
Aitkenhead, N, Chisholm, J I and Stevenson, I P. 1985. Geology of the country around Buxton, Leek and Bakewell. Memoir of the British Geological Survey, England and Wales Sheet 111. 
Shirley, J. 1950. The stratiographical distribution of the lead-zinc ores of Mill Close Mine, Derbyshire and the future prospects of the area. XVIII International Geological congress, London, Vol 7, 353-361. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E111