Caldera Basin
Geological feature in Chile
From Wikipedia, the free encyclopedia
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]
| Caldera Basin | |
|---|---|
| Cuenca de Caldera | |
  | |
| Coordinates | 27°11′50″S 70°45′30″W |
| Etymology | Caldera |
| Region | Atacama Region |
| Country |  Chile |
| State(s) | Copiapó |
| Cities | Caldera |
| Characteristics | |
| On/Offshore | Onshore |
| Boundaries | Pacific Ocean, Chilean Coast Range |
| Hydrology | |
| River(s) | Copiapó |
| Geology | |
| Plate | South American |
| Orogeny | Andean |
| Age | Early Miocene-recent |
| Stratigraphy | Stratigraphy |
Stratigraphy
| 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 | |