The Famatinian granitoids of Southwestern Sierra de San Luis, Argentina

Abstract

The Sierra de San Luis is located in the southern part of the Eastern Sierras Pampeanas. The most conspicuous orogenic events (arc magmatism, deformation and metamorphism) took place during the Lower Paleozoic Famatinian orogeny, overprinting the metamorphic and sedimentary rocks already delineated by the previous Pampean orogeny (Proterozoic? to Early Cambrian). The granitoids were c1assified into pre-, syn- and post-orogenic plutons on the basis of their structural relationship with the penetrative NNE-SSW trending Ordovician structures, attributed to the main Famatinian phase (Ortiz Suarez et al., 1992; Llambias et al., 1998). Available data constrain the low- to high-grade regional metamorphism associated with the deformation mainly within the Early to Middle Ordovician (see synthesis in Sato et al., 2002).