| Ancholme Group | |
|---|---|
| Stratigraphic range: | |
| Type | Group |
| Sub-units | Kellaways Formation, Oxford Clay, West Walton Formation, Ampthill Clay, Kimmeridge Clay |
| Underlies | Portland Group |
| Overlies | Great Oolite Group |
| Thickness | 350m (in central/eastern Lincolnshire) |
| Lithology | |
| Primary | Mudstone |
| Other | Limestone, Marl |
| Location | |
| Region | England |
| Country | United Kingdom |
The Ancholme Group is a geologic group in England. It preserves fossils dating back to the Jurassic period. It has previously been referred to as the Ancholme Clay Group. The group consists of predominantly grey, marine mudstone and silty mudstone with beds of argillaceous limestone nodules. In parts of its range it interfingers with the Corallian Group, which predominantly consists of coralliferous limestones.[1]