Petrography and geochemistry of upper cretaceous-eocene magmatism in the pichaihue area, neuquén province

En:

Rev. Asoc. Geol. Argent. 2011;68(2):173-184

Fecha:

2011

Formato:

application/pdf

Tipo de documento:

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

Descriptores:

Cayanta -  Colipilli -  Neuquén basin -  Tertiary magmatism -  andesite -  Cretaceous -  dike -  emplacement -  Eocene

Descripción:

Magmatism related to the growth and migration of the Andean arc was developed from the 36°40'S to the 38°20'S latitude, in the northwestern sector of the Neuquén Province, by the end of the Mesozoic. Hypabyssal and extrusive facies, which outcrop in the Pichaihue area, were described based on petrologic studies. The first ones are composed of andesites that are emplaced as lacoliths, dikes or sills intruding the Mesozoic sedimentary sequences. In addition, basalts outcrops were recognized. The extrusive facies consist of breccia or massive lavas and little domes. The geochemistry reveals an arc-like calc-alkaline signature with a normal crust and trace-element patterns which suggest a similar source. Based on regional knowledge, three groups are proposed: Cerro Mocho dikes with Ti anomalies and higher Sm/Yb; extrusive facies of the Upper Cretaceous- Paleocene (Rivera Andesite); and the hypabyssal facies of thr Eocene (Colipilli Dikes). Finally, the occurrences of these rocks in this segment of the Andes indicate an important shift to the East of the Upper Cretaceous-Eocene volcanic arc that reveals its easternmost position.
Fil:Mateo FerNández Caso, P.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Montero, D.G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Leal, P.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Ramos, V.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Identificador(es):

http://hdl.handle.net/20.500.12110/paper_00044822_v68_n2_p173_MateoFerNandezCaso

Derechos:

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