Triassic alluvial braidplain and braided river deposits of the La Ternera Formation, Atacama region, northern Chile

C. M. Bell, M. Suárez

Resultado de la investigación: Contribución a una revistaArtículo

8 Citas (Scopus)

Resumen

The La Ternera Formation is a thick (>2,100 m) succession of terrigenous clastic sediments, with andesitic and basaltic intercalations, exposed in the Quebrada de Paipote area of the Atacama Region, northern Chile. The strata were deposited in an active rift basin during Late Triassic to (?) Early Jurassic times. The lower 1,000 m of the studied elastic succession comprises pebbly granule paraconglomerates, unconformably overlying Upper Paleozoic sedimentary successions, volcanics, and granitoids. These sediments were derived from the east and are interpreted as braid-plain deposits. The upper 800 m of the succession comprises interbedded orthoconglomerates, sandstones and mudstones. Abundant plant fossils include trees in growth position and carbonaceous horizons. Small scale depositional cycles were the product of migrating braided-river channel systems. Larger scale successions resulted from tectonic uplift. The sediments of the La Ternera Formation were derived predominantly from a tectonically uplifted area of Upper Paleozoic acidic volcanic and plutonic rocks (Pantanoso Formation, Choiyoi Group). Active uplift on the eastern margin of the sedimentary basin probably occurred along north-south trending faults. Continued subsidence of the basin resulted in a Sinemurian to Bajocian marine transgression. Occurrences of Triassic andesitic and basaltic volcanic rocks both to the west and the east of the La Ternera formation suggest deposition in an intea-volcanic graben or half-graben.

Idioma originalInglés
Páginas (desde-hasta)1-8
Número de páginas8
PublicaciónJournal of South American Earth Sciences
Volumen8
N.º1
DOI
EstadoPublicada - 1 ene 1995

Áreas temáticas de ASJC Scopus

  • Geología
  • Procesos de la superficie terrestre

Huella Profundice en los temas de investigación de 'Triassic alluvial braidplain and braided river deposits of the La Ternera Formation, Atacama region, northern Chile'. En conjunto forman una huella única.

  • Citar esto