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Coquimbo Formation

Coordinates: 30°20′21″S 71°32′03″W / 30.33917°S 71.53417°W / -30.33917; -71.53417
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Coquimbo Formation
Stratigraphic range: MioceneMid Pleistocene
~23–1.2 Ma
Marine terrace exposing strata of the Coquimbo Formation, at Caleta Hornos
TypeGeological formation
UnderliesAlluvium
OverliesLiman Formation
Thickness63 m (207 ft)
Lithology
PrimaryConglomerate, sandstone, siltstone, shale and coquina
OtherClay lenses, terra rossa
Location
Coordinates30°20′21″S 71°32′03″W / 30.33917°S 71.53417°W / -30.33917; -71.53417
Approximate paleocoordinates30°06′S 70°18′W / 30.1°S 70.3°W / -30.1; -70.3
RegionCoquimbo Region
Country Chile
ExtentTongoy Bay
Type section
Named forCoquimbo
Coquimbo Formation is located in Chile
Coquimbo Formation
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.[1]

Fossil content

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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

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References

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  1. ^ 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.
  2. ^ Coquimbo at Fossilworks.org
  3. ^ Bahia de Guayacan at Fossilworks.org
  4. ^ Bahia Herradura at Fossilworks.org
  5. ^ La Cantera at Fossilworks.org
  6. ^ Chanaral de Aceituno at Fossilworks.org
  7. ^ Tongoy area Unit 11 at Fossilworks.org
  8. ^ Tongoy area Unit 4 at Fossilworks.org

Further reading

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