Depósitos de oro orogénico del Paleozoico inferior de la Puna. Su potencialidad a la luz de parámetros geoquímicos e isotópicos y en el marco de la evolución geodinámica de los Andes Centrales Australes.

COIRA, B.; BIERLEIN, F.P.; RODRÍGUEZ, G. Y H., STEIN

La Plata, Argentina.

Congreso; XVI Congreso Geológico Argentino; 2005

Asociación Geológica Argentina

Major and trace element concentrations, and Nd isotope compositions of Ordovician volcanointrusive rocks in the Puna of northwestern Argentina point to their formation in a pericratonic setting above thickened and evolved continental crust. Input from juvenile sources remained limited and there is scarce evidence for oceanic crust or the presence of a terrane-bounding suture in the region. In contrast to analogous terrains elsewhere in the Central Andes (e.g., in Peru and Bolivia), relatively minor orogenic gold mineralisation is known to occur in the Palaeozoic succession in northwestern Argentina. Possible explanations for the lack of more substantial orogenic gold endowment are considered herein. These include the absence of hydrated oceanic substrate in the Puna, lack of 1st-order conduits and the limited extent of crustal shortening and thickening during Ordovician orogenic events. st-order conduits and the limited extent of crustal shortening and thickening during Ordovician orogenic events.order conduits and the limited extent of crustal shortening and thickening during Ordovician orogenic events.