Consideraciones preliminares acerca de la petrogénesis del pórfido cuprífero San Jorge, Uspallata, Mendoza

MEISSL, ESTELA; WILLIAMS, WILLIAM; MADRID, JAVIER; CASTRO DE MACHUCA, BRÍGIDA

Buenos Aires

Congreso; X Congreso Latinoamericano de Geología y VI Congreso Nacional de Geología Económica; 1998

Subsecretaría de Minería de la Nación-SEGEMAR-AAGE

Preliminary considerations regarding the petrogenesis of the San Jorge porphyry copper deposit, Uspallata, Mendoza, Argentina. The San Jorge copper deposit (SJPCD) lies at the southern end of a north-south trend of various hydrothermal deposits that outcrop in the Uspallata graben and its environs. The SJPCD is not a typical porphyry copper deposit but rather an unusual "variation on a theme", in which a sedimentary clastic sequence is host to the higher copper grades. Multiple stages of fracturing , and subsequent influx of hydrothermal fluids derived from the progenitor of the hydrothermal activity, a granodiorite porphyry, resulted in the superimposition of varios sulfide and alteration phases. The pattern of primary mineralization (mainly chalcopyrite and pyrite) and its related alteration is not concentric, but rather pseudolinear in a NNE direction, implicating a strong structural control. Later, the SJPCD was dismembered and brought to surface via a reverse fault. Exposure facilitated leaching and enrichment processes.