Bewcastle Member (BWCB), Carboniferous, Northern England Province
Bewcastle Member is part of the Lyne Formation.
Previously known as the Bewcastle Beds (Day, 1970).
Cyclical sequences of sandstone, siltstone, mudstone and thin limestones, locally dolomitic (‘cementstones’); locally thin seatearths, nodular algal limestone and traces of coal (see Day, 1970; Leeder, 1974).
A partial type section that includes nearly all of the Bewcastle Member, from the Bogside Limestone to just above a probable equivalent of the Junction Limestone, is exposed in Ashy Cleuch (NY 5648 7698 to 5808 7665) (Day, 1970).
Lower and upper boundaries
At Bewcastle, the lower boundary is defined at the base of the Bogside Limestone, and is conformable on the alternating thin limestones, ‘cementstones’ and mudstones of the Lynebank Member (Figure 11, Column 2).
The upper boundary is conformable with the base of the lowermost algal bed (M.A.1 of Day, 1970) of the rhythmically alternating limestone and mudstone with nodular algal beds of the Main Algal Member.
About 180 m at Bewcastle.
Distribution and regional correlation
The Northumberland–Solway Basin, but described only in the Bewcastle region (Day, 1970).
Chadian to Arundian.
- Day, J B W.1970.Geology of the country around Bewcastle.Memoir of the Geological Survey of Great Britain, Sheet 12 (England and Wales).
- Leeder, M R.1974.Lower Border Group (Tournaisian) fluviodeltaic sedimentation and palaeogeography of the Northumberland Basin.Proceedings of the Yorkshire Geological Society, Vol. 40, 129–180.