| Las Juntas Formation | |
|---|---|
| Stratigraphic range: Hauterivian ~ | |
| Type | Geological formation |
| Unit of | Cáqueza Group |
| Sub-units | Arenisca de Almeida Mb. Lutitas Intermedias Mb. Arenisca de El Volador Mb. |
| Underlies | Fómeque Fm., Apón Fm. |
| Overlies | Macanal Formation |
| Thickness | up to 910 m (2,990 ft) |
| Lithology | |
| Primary | Sandstone |
| Other | Shale |
| Location | |
| Coordinates | 5°00′49″N 73°27′27″W / 5.01361°N 73.45750°W |
| Region | Altiplano Cundiboyacense & Tenza Valley Eastern Ranges Andes |
| Country |  Colombia |
| Type section | |
| Named for | Cerro Las Juntas |
| Named by | Rodríguez & Ulloa |
| Location | Guateque |
| Year defined | 1979 |
| Coordinates | 5°00′49″N 73°27′27″W / 5.01361°N 73.45750°W |
| Region | Boyacá |
| Country | Colombia |
The Las Juntas Formation or Las Juntas Sandstone (Spanish: (Formación) Areniscas de Las Juntas, Kiaj, Kialj, K1j) is a geological formation of the Altiplano Cundiboyacense and Tenza Valley, Eastern Ranges of the Colombian Andes. The Las Juntas Formation is found in the departments Cundinamarca, Boyacá and Casanare. The predominantly sandstone formation dates to the Early Cretaceous period; Hauterivian epoch, and has a maximum thickness of 910 metres (2,990 ft).