Scaleber Quarry Limestone Member: Difference between revisions
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Scaleber Quarry Limestone Member (SQLM), Carboniferous, Northern England Province
Scaleber Quarry Limestone Member is a member of the Kilnsey Limestone Formation and part of the Great Scar Limestone Group
Name
The name is derived from Scaleber Quarry (SD 9225 5328). It was previously known as the Kilnsey Limestone and originally defined by Hudson (1930[1]). Arthurton et al. (1988[2]) is the principal reference.
Lithology
Well-bedded, thin and thick beds of mid and mid–dark grey, fine- to coarse-grained limestone, with minor mudstone beds. Bioclastic packstones characterise the lower part of the member, passing up to packstones and grainstones. Bands and nodules of black chert occur locally in the lower part of the member.
Stratotype
The type locality is Scaleber Quarry (SD 8407 6263) where a 12 m section 18 m above the base of the member is exposed. Reference sections are provided by the Cominco S2 Borehole (BGS Registration Number SD86SW/6) (SD 8491 6345) at Low Barn, Stockdale Beck, from 224.2? to 363.9? m depth, and Kilnsey Crag (SD 9735 6846) where 29.m are exposed at outcrop in a cliff section. Both reference sections include the top and base, and full thickness, of the member.
Lower and upper boundaries
The base is taken where the mid grey limestone of the Scaleber Quarry Limestone Member overlies the dark grey limestone and mudstones of the Scaleber Force Limestone Member (Figure 15, Column 6). This boundary is typically gradational and for convenience the base is taken at the top of the highest prominent mudstone.
The top of the member is drawn at the conformable, gradational and slightly diachronous upward passage from mid–dark grey limestone of the Scaleber Quarry Limestone Member to the pale grey limestone of the Cove Limestone Member (Malham Formation).
Thickness
Up to 134 m thick in the Cominco Borehole S2, decreasing to 29 m at Kilnsey Crag (see 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).
Age and biostratigraphical characterisation
Holkerian. The member contains an abundant macrofauna characterised by cerioid and fasciculate lithostrotionid corals.
References
- ↑ 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).