Great Scar Limestone Group
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The Great Scar Limestone Group is a lithostratigraphical term referring to a succession of generally fossiliferous rock strata which occur in the Pennines in northern England and in the Isle of Man within the Tournaisian and Visean stages of the Carboniferous Period.
| Great Scar Limestone Group | |
|---|---|
| Stratigraphic range: Arundian-Brigantian | |
| Type | Group |
| Unit of | Carboniferous Limestone Supergroup |
| Sub-units | See text |
| Underlies | Yoredale Group |
| Overlies | Ravenstonedale Group |
| Thickness | Up to 800 m (2,600 ft) |
| Lithology | |
| Primary | Limestone |
| Other | Mudstone, siltstone, sandstone |
| Location | |
| Region | England |
| Country | United Kingdom |
| Extent | Pennines to Isle of Man |
It is contained within the Carboniferous Limestone Supergroup.[1]
Basinal successions
Stainmore Trough
The sequence in the Stainmore Trough is thus (youngest at top):
- Ashfell Sandstone (Arundian age)
- Breakyneck Scar Limestone (Arundian age)
- Red Hill Formation
- Brownber Formation (Chadian age)
- Scandal Beck Limestone (Chadian age)
- Coldbeck Limestone (Chadian age)
On the Alston Block corresponding to the North Pennines, the sequence contains the Melmerby Scar Limestone Formation.
Orton area
In the Orton area, the sequence is:
- Knipe Scar Limestone
- Potts Beck Limestone
- Ashfell Limestone
- Ashfell Sandstone
- Breakyneck Scar Limestone
- Brownber Formation
- Scandal Beck Limestone
- Coldbeck Limestone
Kendal, Skelsmergh and Deepslack outliers
In south Cumbria, the sequence is:[2]
- Urswick Limestone
- Park Limestone
- Dalton Formation (time-equivalent of Breakyneck Scar Limestone in Stainmore Trough) (Arundian age)
Isle of Man
On the Isle of Man, the following sequence is identified in the Castletown area:[3][4]
- Knockcrushen Formation (wackestones, packstones and mudstones; of Holkerian age)
- Derbyhaven Formation (packstones and mudstones with some mudstones and siltstones; of Arundian age)
- Skillicore Member
- Sandwick Member
- Turkeyland Member
