Las rocas granitoides de la región de Cafayate, provincia de Salta. Aspectos petrológicos y geoquímicos

RAPELA, C.W.

Revista Asociación Geológica Argentina

Asociación Geológica Argentina

Lugar: Buenos Aires; Año: 1976 vol. 31 p. 260 - 278

0004-4822

The petrology and geochemistry of granitoids intruded at different levels in the metamorphic basement of Cafayate, Salta, are here considered. The metamorphic and tectonic history were already described in a previous paper (Rapela, 1976). The bodies have been classified as syn late and post-kinematic granites according to their occurrence features; their petrographic characteristics and modal composition are also treated”. Chemical analyses of rocks were performed (57 semples); the major elements being investigated and the resulting variation diagrams compared. The results obtained were analysed in the light of experimental petrology data. It was clearly concluded that the studied granitoids were formed through anatexis of paragneisses and their modal and chemical composition vas the result of a solid-liquid equilibrium. According to petrographic evidence it is suggested that some sodium vas added during the final phase of granite emplacement. Geochemical measured sections along the bodies show that magmatic evolution could be developed in a predominant E-W direction with a more acid phases towards the east.