Trincheras Formation
| Trincheras Formation | |
|---|---|
| Stratigraphic range: Early Aptian ~ | |
| Type | Geological formation |
| Unit of | Villeta Group |
| Sub-units | Anapoima Mb., El Tigre Mb. |
| Underlies | Socotá Fm., El Peñón Fm. |
| Overlies | Murca Fm., La Naveta Fm., Útica Fm. |
| Thickness | up to 1,260 m (4,130 ft) |
| Lithology | |
| Primary | Shale |
| Other | Sandstone, limestone |
| Location | |
| Coordinates | 4°30′13″N 74°36′22″W / 4.50361°N 74.60611°W |
| Region | Altiplano Cundiboyacense Eastern Ranges, Andes |
| Country | Colombia |
| Type section | |
| Named for | Quebrada Trincheras |
| Named by | Cáceres & Etayo |
| Location | Apulo |
| Year defined | 1969 |
| Coordinates | 4°30′13″N 74°36′22″W / 4.50361°N 74.60611°W |
| Region | Cundinamarca |
| Country | Colombia |
Paleogeography of Northern South America 120 Ma, by Ron Blakey | |
The Trincheras Formation (Spanish: Formación Trincheras, Kitr) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consisting of a lower unit of calcareous shales and an upper sequence of shales dates to the Early Cretaceous period; Early Aptian epoch and has a maximum thickness of 1,260 metres (4,130 ft). The formation, deposited in a marine platform environment, part of a transgressive cycle, hosts ammonite, bryozoan, mollusc and echinoid fossils.