| Barzalosa Formation | |
|---|---|
| Stratigraphic range: ~Mid Eocene-Oligocene or Oligocene-Early Miocene ~ | |
| Type | Geological formation |
| Underlies | Honda Gp., Carmen de Apicalá Conglomerate |
| Overlies | La Tabla Fm., Olini Gp., Seca Fm. |
| Thickness | ~360 m (1,180 ft) |
| Lithology | |
| Primary | Conglomerates |
| Other | Sandstones, siltstones, shale, gypsum |
| Location | |
| Coordinates | 4°21′50.2″N 74°47′29.8″W / 4.363944°N 74.791611°W |
| Approximate paleocoordinates | 2°42′N 71°12′W / 2.7°N 71.2°W |
| Region | Upper Magdalena Valley Central & Eastern Ranges Andes |
| Country |  Colombia |
| Type section | |
| Named for | Barzalosa |
| Named by | Scheibe |
| Location | Girardot |
| Year defined | 1934 |
| Coordinates | 4°21′50.2″N 74°47′29.8″W / 4.363944°N 74.791611°W |
| Region | Cundinamarca |
| Country | Colombia |
 Paleogeography of Northern South America 35 Ma, by Ron Blakey | |
The Barzalosa Formation (Spanish: Formación Barzalosa, Pgb, Pgba) is a fossiliferous geological formation of the Upper Magdalena Valley and the bounding foothills of the Central Ranges and Eastern Ranges of the Colombian Andes. The formation consists of conglomerates, sandstones and siltstones. The Barzalosa Formation probably dates to the Late Paleogene to Early Neogene period; Oligocene to Early Miocene epochs, and has an approximate thickness of 360 metres (1,180 ft). Fossils of Balanerodus logimus, Lophiodolodus chaparralensis, Xenastrapotherium chaparralensis, Protheosodon sp. and Proadinotherium sp. have been uncovered from the formation in Chaparral, Tolima.