Sedimentology and paleoenvironments of the Patagoniano and the transition to the Santa Cruz Formation south of Lago Argentino, southern Patagonia

En:

Rev. Asoc. Geol. Argent. 2010;66(3):406-417

Fecha:

2010

Formato:

application/pdf

Tipo de documento:

info:eu-repo/semantics/article
info:ar-repo/semantics/artículo
info:eu-repo/semantics/publishedVersion

Descriptores:

Cenozoic -  Marine transgression -  Patagonia -  Patagoniano -  Santa Cruz Formation -  Cenozoic -  conglomerate -  depositional sequence -  discontinuity

Descripción:

Sedimentology and paleoenvironments of the Patagoniano and its transition to the Santa Cruz Formation south of Lago Argentino, southern Patagonia. Detailed sedimentological analysis of the Patagoniano and its transition to the Santa Cruz Formation has been carried out south of Lago Argentino, in southern Patagonia. The 180 meters thick succession of fossiliferous sandstones was subdivided into twelve lithofacies, grouped in three facies associations. From base to top we defined the facies association I, dominated by massive, bioturbated and fossiliferous sandstones; the facies association II, dominated by fining upward cycles of cross-stratified sandstones and heterolithic facies; and the facies association III dominated by thin conglomeratic levels interbedded with mudstones rich in plant remains and paleosoils. The facies association I is interpreted as the deposit of a transgressive, shallow sea with oyster rich biogenic accumulations, finally evolving to a coastal plain paleoenvironment. A new transgression originated the discontinuity underlying the facies association II, which was interpreted as a progradational estuarine system. Finally, the ongoing progradation produced the fluvial meandering system of facies association III, assigned to the Santa Cruz Formation. The new name "Estancia 25 de Mayo" is formalized here for the Patagoniano in the southernmost Cordillera Patagónica, instead of the problematic name Centinela Formation. The Estancia 25 de Mayo Formation was subdivided in two members: the lower Quién Sabe Member, equivalent to the facies association I, and the upper Bandurrias Member, equivalent to the (facies association II).
Fil:Cuitiño, J.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Scasso, R.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Identificador(es):

http://hdl.handle.net/20.500.12110/paper_00044822_v66_n3_p406_Cuitino

Derechos:

info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/2.5/ar