Coupland Syke Limestone Member
Coupland Syke Limestone Member is part of the Great Scar Limestone Group
The name was proposed by Pattison (1990) for the limestones that occur between the Park Hill Limestone Member and the Brownber Formation.
Packstone, dark grey, regularly bedded, blocky, partly dolomitised and bituminous. Cyclically interbedded with thin mudstone and siltstone beds. There are traces of chert. The limestone beds are a fairly constant 0.75 m thickness.
A partial type section is in a stone quarry (working in 2005) on the B6261 road west of the village of Orton, Cumbria (NY 5975 0920). It occurs as a thick-bedded, bituminous limestone (wackestone) (see McCormac, 2001). This differs from similar thick-bedded rocks in disused quarries to the west (NY 5984 0924 and 5924 0968) where the blocky limestones are commonly or extensively dolomitised (possibly in association with minor faults) and geodic (see Pattison, 1990; McCormac, 2001). A reference section is Stapestones Quarry (disused), Raisbeck, Cumbria (NY 6496 0692) where 11 m of limestone (with some dolomitisation) are exposed (see Pattison, 1990).
Lower and upper boundaries
The base of the member is taken at the top of a 5 m unit of interbedded sandstone and mudstone, which forms a topographical depression at the top of the underlying Park Hill Limestone Member. The junction is nowhere exposed, but the interbedded unit was formerly seen in a road cutting at (NY 7248 0448) during the construction of the Ravenstonedale By-pass, and the junction was recorded in M6 Site Investigation Boreholes at (NY 5885 0998).
The top of the member is taken at the base of the overlying Brownber Formation (Figure 9, Column 16) where there is a change from dark grey cyclically bedded limestone to pale grey ooidal limestone and calcarenite.
Between 40 and 50 m.
Distribution and regional correlation
Ravenstonedale, Cumbria between the M6 road and the Dent Fault Zone, south of Kirkby Stephen.
Age and biostratigraphical characterisation
Chadian. Colonial corals (notably genus Dorlodotia) are common within the member.
- Pattison, J.1990.Geology of the Orton and Sunbiggin Tarn districts: 1:10 000 sheets NY60NW and NE.British Geological Survey Technical Report, WA/90/12
- McCormac, M.2001.The Upper Palaeozoic rocks of the Shap and Penrith district, Edenside, Cumbria.British Geological Survey Research Report, RR/01/10