| Cody Shale | |
|---|---|
| Stratigraphic range: Late Cretaceous | |
| Type | Sedimentary |
| Sub-units | see text |
| Underlies | Mesaverde Formation |
| Overlies | Frontier Formation |
| Thickness | 500-1000 m |
| Lithology | |
| Primary | shale |
| Location | |
| Region | Montana folded belt province, Central Montana uplift, Big Horn basin, Powder River basin, Wind River basin |
| Country | United States |
| Extent | Wyoming, Idaho, Montana |
| Type section | |
| Named for | Cody, Wyoming |
| Named by | C. T. Lupton, 1916[1] |
The Cody Shale is a Late Cretaceous geologic formation. It is mapped in Wyoming, Idaho, and Montana.
The formation is described by W.G. Pierce as follows: upper part is buff, sandy shale and thinly laminated buff sandstone; lower part is dark gray, thin-bedded marine shale.[2]
The formation is divided into many members that vary regionally. Alphabetically:[3]
Certain members rise to formation rank in other areas; for example, the Greenhorn is classified as a formation in a number of states, particularly in Colorado and Kansas.