Tullock Member
| Tullock Member | |
|---|---|
| Stratigraphic range: Early Paleocene (Puercan) | |
| Type | Member |
| Unit of | Fort Union Formation |
| Underlies | Lebo Member |
| Overlies | Hell Creek Formation (MT), Lance Formation (WY) |
| Thickness | 90–400 m (Powder River Basin) |
| Location | |
| Region | Montana, Wyoming |
| Country | United States |
| Type section | |
| Named for | Tullock Creek |
| Named by | Rogers and Lee (1923) |
The Tullock Member is a geologic member in Montana and Wyoming, forming the lowermost part of the Fort Union Formation. It is also known less commonly as the Tullock Formation, forming part of the Fort Union Group.. It preserves fossils dating back to the Paleogene period.