| Dyrham Formation | |
| Type: | Formation |
| Period: | Pliensbachian |
| Prilithology: | mudstone, silt, sand |
| Otherlithology: | ferruginous limestone |
| Namedfor: | Dyrham |
| Region: | England |
| Country: | United Kingdom |
| Unitof: | Lias Group |
| Subunits: | Eype Clay Member, Down Cliff Sand Member, Thorncombe Sand Member |
| Underlies: | Beacon Limestone Formation, Marlstone Rock Formation |
| Overlies: | Charmouth Mudstone Formation |
| Thickness: | ~125 m |
| Area: | Wessex Basin, Worcester Basin, East Midlands Shelf |
The Dyrham Formation is a geologic formation in England. It preserves fossils dating back to the early part of the Jurassic period (Pliensbachian).[1]