| Downton Castle Sandstone | |
| Type: | Formation |
| Period: | Pridoli |
| Prilithology: | Sandstone |
| Otherlithology: | Siltstone, Mudstone |
| Region: | England |
| Unitof: | Old Red Sandstone |
| Subunits: | Lower Bone Bed Member, Platyschisma Shale Member |
| Underlies: | Temeside Shale |
| Thickness: | 15m in type area; 17m at Ludlow, 15-20m in South Staffordshire |
The Downton Castle Sandstone is a geologic formation in England. It preserves fossils dating back to the Silurian period. As its name would suggest the formation predominantly consists of sandstone with minor siltstone and mudstone.[1] The oldest known Trigonotarbid Palaeotarbus is known from the formation.