Scaleber Force Limestone Member
The name is derived from Scaleber Force (SD 8407 6256). It was previously known as the Kilnsey Limestone-with-mudstone Member and originally defined by Hudson (1930). Arthurton et al. (1988) is the principal reference.
Bioturbated, well-bedded, fine- to coarse-grained dark limestones (packstones and subordinate wackestones), generally argillaceous with common detrital quartz, and with common mudstone partings and interbeds up to 1.8.m thick.
The type locality is Scaleber Force (SD 8407 6256) where a 22 m section is exposed. A reference section is the Cominco S7 Borehole (BGS Registration Number SD86SE/6) (SD 8541 6378) near Settle, North Yorkshire, which includes the full thickness of the member from 58.5 to 120.1 m depth.
Lower and upper boundaries
The base of the Scaleber Force Limestone Member is drawn where the dark limestones rest sharply and conformably on paler grainstone of the Chapel House Limestone Formation (Figure 15, Column 6).
The top of the member is taken where the dark grey limestones of the Scaleber Force Limestone Member are overlain by mid–dark grey limestone of the Scaleber Quarry Limestone Member.
North of the Middle Craven Fault the member is 22–58 m thick. South of the fault it is 61.6 m thick at the type locality (see Stratotype above).
Distribution and regional correlation
The member occurs in a series of inliers in the southern part of the Askrigg Block, North Yorkshire, including Kilnsey (SD 97 68), Langcliffe (SD 82 65), and Austwick (SD 77 68).
- Hudson, R G S.1930.The Carboniferous of the Craven Reef Belt; and the Namurian unconformity at Scaleber, near Settle.Proceedings of the Geologists’ Association, Vol. 41, 290–322.
- Arthurton, R S, Johnson, E W, and Mundy, D J C.1988.Geology of the Country around Settle.Memoir of the British Geological Survey, Sheet 60 (England and Wales).