Caldera Basin
Cuenca de Caldera
Map showing the location of Caldera Basin
Map showing the location of Caldera Basin
Coordinates27°11′50″S 70°45′30″W / 27.19722°S 70.75833°W / -27.19722; -70.75833
EtymologyCaldera
RegionAtacama Region
Country Chile
State(s)Copiapó
CitiesCaldera
Characteristics
On/OffshoreOnshore
BoundariesPacific Ocean, Chilean Coast Range
Hydrology
River(s)Copiapó
Geology
PlateSouth American
OrogenyAndean
AgeEarly Miocene-recent
StratigraphyStratigraphy

Caldera Basin (Spanish: Cuenca de Caldera) is a sedimentary basin located in the coast of northern Chile west of Copiapó. The basin has a fill of marine sediments of Late Cenozoic age. With a north-south extension of 43 kilometres (27 mi) and an east-west width of 20 kilometres (12 mi) the basin occupies an area between the coast and the Chilean Coast Range and between the port of Caldera and the mouth of Copiapó River. The sedimentary fill rests on metamorphic rocks of Paleozoic age and on plutonic rocks of Mesozoic age.[1]

Stratigraphy

The following units make up the sedimentary fill[1]
Name Age Lithologies Depositional environment
Caldera Beds Pleistocene
Bahía Inglesa Formation Quebrada Blanca Late Miocene Conglomerate, sandstone, biocalcirudite Shoreface, outer shelf, tsunami
Rocas Negras Calcirudite, biocalciarenite Shoreface
Mina Fosforita Sandstone, siltstone, shale Uppermost continental slope, shoreface
Chorrillos Clast-supported conglomerate Submarine canyon debris flow fill, formed possibly by a tsunami
La Higera Shale with gypsum veins, sandstone, siltstone, diatomaceous clay Outer shelf or uppermost continental slope
Cerro Ballena Silty sandstone Supratidal flat
Punta Totoral Biocalcarenite, biocalcirudite, matrix-supported conglomerate Rapid sea-level oscillations
Puerto Viejo Sandstone, siltstone, claystone, shale, microcoquina Shoreface, marine transgression
El Pimiento Biocalcarenite, quartzarenite Shoreface
Angostura Formation Early to Mid-Miocene Matrix-supported conglomerate High-energy river mouth

References

  1. ^ a b Le Roux, Jacobus; Achurra, Luciano; Henríquez, Álvaro; Carreño, Catalina; Rivera, Huber; Suárez, Mario E.; Ishman, Scott E.; Pyenson, Nicholas D.; Gutstein, Carolina S. (2016). "Oroclinal bending of the Juan Fernández Ridge suggested by geohistory analysis of the Bahía Inglesa Formation, north-central Chile" (PDF). Sedimentary Geology. 333: 32–49. Bibcode:2016SedG..333...32L. doi:10.1016/j.sedgeo.2015.12.003.

Further reading

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