| Willwood Formation | |
|---|---|
| Stratigraphic range: Thanetian-Ypresian (Clarkforkian-Bridgerian) ~ | |
| Type | Geological formation |
| Sub-units | Gray Bull beds, Sand Coulee beds, Sand Creek Facies, Wa-1 Zone |
| Lithology | |
| Primary | Mudstone, shale |
| Other | Sandstone, conglomerate |
| Location | |
| Coordinates | 44°30′N 108°00′W / 44.5°N 108.0°W |
| Approximate paleocoordinates | 49°12′N 90°48′W / 49.2°N 90.8°W |
| Region |  Wyoming |
| Country |  USA |
| Extent | Bighorn Basin |
| Type section | |
| Named for | Shale, mudstone, limestone |
  Willwood Formation (the United States)  Willwood Formation (Wyoming) | |
The Willwood Formation is a sedimentary sequence deposited during the late Paleocene to early Eocene, or Clarkforkian, Wasatchian and Bridgerian in the NALMA classification.[1][2]
- ^ Willwood Formation at Fossilworks.org
- ^ Neasham & Vondra, 1972