Kilnsey Limestone Formation
Kilnsey Limestone Formation is part of the Great Scar Limestone Group
The formation comprises dark to mid–pale grey, thick to thin-bedded, bioclastic limestone with mudstone beds and partings.
See Arthurton et al. (1988). The partial type section is at Kilnsey Crag (SD 9735 6846) near Malham, North Yorkshire, with 8 m of the upper part of the Scaleber Force Limestone Member and 29 m of the overlying Scaleber Quarry Limestone Member. A reference section is in the Stockdale Farm (Cominco S7) Borehole (BGS Registration Number SD86SE/6) (SD 8541 6378) near Settle, North Yorkshire with the formation present from 15.2 to 120.1.m depth, which includes 61.6 m thickness of the Scaleber Force Limestone Member and 43.2.m in the Scaleber Quarry Limestone Member.
Lower and upper boundaries
The lower boundary of the formation is drawn at the base of the dark grey limestones with mudstone partings of the Scaleber Force Limestone Member where it rests sharply and conformably on paler grainstone of the Chapel House Limestone Formation (Figure 15, Column 6).
The upper boundary of the formation is drawn at the conformable upward passage from mid–dark grey limestone of the Scaleber Quarry Limestone Member to pale grey limestone of the Cove Limestone Member, Malham Formation.
The maximum thickness is about 224 m in boreholes south of the Middle Craven Fault. The formation thins rapidly northwards to 53 m in the Kilnsey area.=== Distribution and regional correlation === Limited to 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
Arundian to Holkerian. Biostratigraphically important fossils recorded within the formation include foraminifers (diagnostic of both stages), Delepinea carinata (which is characteristic of the Arundian), and Lithostrotion sensu stricto (cerioid), which is not recorded below the base of the Holkerian (Mitchell, 1989).
See also Appendix 1. Members of the Kilnsey Formation in ascending stratigraphical order include:
- Mundy, D J C, and Arthurton, R S.1980.Field meetings: Settle and Flasby.Proceedings of the Yorkshire Geological Society, Vol. 43, 32–36.
- 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).