An example of the use of the Sm/Nd isotopes: The (Ultra-) Mafic complexes of the Sierras de Córdoba (Argentina)

STEENKEN, A.; LÓPEZ DE LUCHI, M. G.; SIEGESMUND, S. ; WEMMER, K.

Antofagasta

Congreso; 13th Congreso Geológico Chileno; 2012

Univ Católica del Norte-Sociedad Geológica de Chile

Abstract: The Eastern Sierras Pampeanas (Argentina) were attributed to the Ediacaran to early Cambrian orogen developed on the western margin of the Rio de La Plata craton. The rocks of the Pampean orogen are made up by medium to high grade gneisses, schists, marbles and amphibolites that were deposited in a marine sequence before the orogenic process. Intrusive activity started the Early Cambrian, the Late Cambrian to early Ordovician and terminated in the Devonian with metaluminous to peraluminous granitoids. The Pampean orogen in the ranges of Córdoba is separated by two interrupted belts of mafic to ultramafic units that were interpreted as ophiolitic sequences. We have new Sm/Nd isotope data on the mafic and ultramafic units. In previous works were the crustal provenance based on Sm/Nd isotope data analyzed. It is our attempt to correlate the Sm/Nd data entre ambos units.