Dos Bocas Formation
| Dos Bocas Formation | |
|---|---|
| Stratigraphic range: Chattian (Deseadan) ~ | |
| Type | Geological formation |
| Unit of | Subibaja Group |
| Underlies | Villingota Formation |
| Overlies | Zapotal Formation |
| Lithology | |
| Primary | Sandstone |
| Location | |
| Coordinates | 1°48′S 80°48′W / 1.8°S 80.8°W |
| Approximate paleocoordinates | 3°36′S 75°30′W / 3.6°S 75.5°W |
| Region | Santa Elena Province |
| Country |  Ecuador |
| Extent | Progreso Basin |
  Dos Bocas Formation (Ecuador) | |
The Dos Bocas Formation is a Chattian, about 26 to 24 Ma,[1] (Deseadan in the SALMA classification) geologic formation of the Progreso Basin in southwestern Ecuador.
Description
The formation comprises moderately-sorted, fine to medium sandstones with angular quartz-feldspathic clasts. Conspicuous rounded green grains are probably glauconite, but berthierine cannot be dismissed. The matrix is micritic and volcanogenic, possibly bentonitic. The formation was deposited in an estuarine to mid shelf environment. Fossils of sharks, turtles and the tropical Urkudelphis were recovered from the formation.[1]
Fossil content
The formation has provided fossils of:
See also
References
- ^ a b Montañita/Olón at Fossilworks.org
- ^ Tanaka et al., 2017
Bibliography
- Tanaka, Y; J. Abella; Gl Aguirre Fernández; M. Gregori, and R.E. Fordyce. 2017. A new tropical Oligocene dolphin from Montañita/Olón, Santa Elena, Ecuador. PLoS One 12. e0188380. Accessed 2019-02-09.
Further reading
- Lorenzo, Erica; Wladimir Andrés Roca Beltrán; Manuel Martínez; Antonio Morato; Paulo César Escandón Panchana, and Cristian Paul Álvarez Domínguez. 2018. Correlación geoquímica entre crudos y rocas del sistema petrolero de la península de Santa Elena y el golfo de Guayaquil. Boletín de Geología 40. 31–42. Accessed 2018-10-01.