| Coquimbo Formation | |
|---|---|
| Stratigraphic range: Miocene–Mid Pleistocene ~23–1.2 Ma PreꞒ Ꞓ O S D C P T J K Pg N | |
.jpg) Marine terrace exposing strata of the Coquimbo Formation, at Caleta Hornos | |
| Type | Geological formation |
| Underlies | Alluvium |
| Overlies | Liman Formation |
| Thickness | 63 m (207 ft) |
| Lithology | |
| Primary | Conglomerate, sandstone, siltstone, shale and coquina |
| Other | Clay lenses, terra rossa |
| Location | |
| Coordinates | 30°20′21″S 71°32′03″W / 30.33917°S 71.53417°W / -30.33917; -71.53417 |
| Approximate paleocoordinates | 30°06′S 70°18′W / 30.1°S 70.3°W / -30.1; -70.3 |
| Region | Coquimbo Region |
| Country |  Chile |
| Extent | Tongoy Bay |
| Type section | |
| Named for | Coquimbo |
  Coquimbo Formation (Chile) | |
Coquimbo Formation (Spanish: Formación Coquimbo) is a Miocene to Middle Pleistocene sedimentary formation located in Coquimbo Region in Norte Chico, Chile. The lowermost unit belongs to the lower Miocene, with the third-deepest unit dated at 11.9 ± 1.0 Ma. The uppermost unit of the formation is estimated at 1.2 Ma. In the area of Tongoy, the Coquimbo Formation was deposited in an ancient bay that was formed in a graben or half-graben, with a normal fault dipping east. Sea level changes during the Holocene have caused erosion to cut several marine terraces into the formation.
Fossil content
The following fossils have been found in the formation:
| SALMA | Group | Fossils | Notes |
|---|---|---|---|
| Montehermosan | Mammals | Delphinus domeykoi, Megaptera hubachi, Pliopontos sp., ?Squalodon sp., Balaenidae indet. | |
| Birds | cf. Palaeospheniscus sp., Spheniscus sp., Diomedeidae indet., Spheniscidae indet. | ||
| Fish | Carcharodon carcharias | ||
| Mayoan | Cosmopolitodus hastalis |
See also
References
- Le Roux, J.P.; Olivares, Danisa M.; Nielsen, Sven N.; Smith, Norman D.; Middleton, Heather; Fenner, Juliane; Ishman, Scott E. (2006). "Bay sedimentation as controlled by regional crustal behaviour, local tectonics and eustatic sea-level changes: Coquimbo Formation (Miocene–Pliocene), Bay of Tongoy, central Chile" (PDF). Sedimentary Geology. 184 (1–2): 133–153. Bibcode:2006SedG..184..133L. doi:10.1016/j.sedgeo.2005.09.023. Retrieved 11 April 2016.
- Coquimbo at Fossilworks.org
- Bahia de Guayacan at Fossilworks.org
- Bahia Herradura at Fossilworks.org
- La Cantera at Fossilworks.org
- Chanaral de Aceituno at Fossilworks.org
- Tongoy area Unit 11 at Fossilworks.org
- Tongoy area Unit 4 at Fossilworks.org
Further reading
- C. Acosta Hospitaleche, J. Canto, and C. P. Tambussi. 2006. Pingüinos (Aves, Spheniscidae) en Coquimbo (Mioceno Medio-Plioceno Tardio), Chile y su vinculación con las corrientes oceánicas. Revista Española de Paleontología 21(1):115-122
- Staig, Felipe; Hernández, Sebastián; López, Patricio; Villafaña, Jaime A.; Varas, Cristian; Soto, Luis Patricio; Carrillo Briceño, Jorge D. (2015), "Late Neogene Elasmobranch fauna from the Coquimbo Formation, Chile", Revista Brasileira de Paleontologia, 18 (2): 261–272, doi:10.4072/rbp.2015.2.07, retrieved 2017-08-15
