| Roxby Formation | |
| Type: | Group |
| Period: | Permian |
| Prilithology: | Mudstone and siltstone, reddish brown, with subordinate sandstone. |
| Namedfor: | Roxby, North Yorkshire |
| Region: | England |
| Underlies: | Sherwood Sandstone Group |
| Overlies: | Appleby Group |
| Thickness: | up to 1025m (3,363feet) |
| Extent: | east England |
The Roxby Formation, previously known as the Permian Upper Marls, is a formation from the Guadalupian-Early Triassic of eastern England (formation dies out at Nottinghamshire).[1] The formation is made up largely of mudstone and siltstone, reddish brown, with subordinate sandstone.[2]