| Santa Marta Formation | |
|---|---|
| Stratigraphic range: Santonian-Campanian | |
 | |
| Type | Geological formation |
| Unit of | Marambio Group |
| Sub-units | Alpha Member, Beta Member |
| Underlies | Snow Hill Island Formation |
| Overlies | Hidden Lake Formation |
| Thickness | 1,000 m (3,300 ft) |
| Lithology | |
| Primary | Mudstone, sandstone |
| Other | Siltstone, tuff |
| Location | |
| Coordinates | 63°00′S 57°00′W / 63.0°S 57.0°W |
| Approximate paleocoordinates | 60°54′S 67°36′W / 60.9°S 67.6°W |
| Region | James Ross Island |
| Country |  Antarctica |
  Santa Marta Formation (Antarctica) | |
The Santa Marta Formation is a geologic formation in Antarctica. It, along with the Hanson Formation and the Snow Hill Island Formation, are the only formations yet known on the continent where dinosaur fossils have been found. The formation outcrops on James Ross Island off the coast of the northern tip of the Antarctic Peninsula. In its entirety, the Santa Marta Formation is on average one kilometer thick.