Petrology and Geochemistry of felsic and intermediate rocks from the south-central of La Pampa province, Argentina. Its correspondence with the Choiyoi magmatism.

Abstract

Permian and Triassic igneous rocks from La Pampa province were initially part of the Choiyoi magmatism later, this rocks where included in the Permian-Triassic Intracratonic Magmatic Corridor of La Pampa excluding them from Choiyoi magmatism because they were considered of intraplate environment with an anorogenic signature. Petrological and geochemical studies on ignimbrites, lavas and porphyries from south-central of La Pampa province, identified rocks with arc characteristics and with transitional characteristics between magmatic arc and intraplate. A comparative analysis with Permo-Triassic rocks from other sectors of La Pampa province and the San Rafael Block, Mendoza province indicates that south-central of La Pampa rocks have similar characteristics in geochemistry and age to the units of the lower and upper sections of the Choiyoi magmatism.