El basamento ígneo-matórfico del borde occidental del salar Centenario. Petrografía y estructura. Puna Austral, Salta.

DOMINGUEZ R.F., R. BECCHIO, R. MARTINO, J.G. VIRAMONTE Y M. PIMENTEL

RAGA

Asociación Geológica Argentina

Lugar: Buenos Aires; Año: 2006 vol. D p. 161 - 168

0004-4822

Igneous- metamorphic basement of the western border of Salar Centenario. Petrography and structure. Puna Austral, Argentina. In this paper we report new data about the igneous-matamorphic outcrops of the wesstern border of salr Centenario, in the subprovince of Puna Austral. These outcrops are constituted by different lithologies arraanged in NNE-SSw tending belts, among which there two micas and Grt-Sil gneisse, granitoids, schists and metaquarzite, and St-Grt-Sil schist.These rocks register  a metamorphism M1 associated with a deformation event D1 thar originates a foliation S 1 represented by Qtz+Plasg+Bt+Ms paragenesis. The highest grade event M2 associated with an D2 gives rise a S2 represented bu Bt-Ms-Sil-Grt-Qtz-Plag (Kfs) assemblages for felsic rocks and Hbl-Plag-Qtz association for basic rocks (amphibolite facies). By the U/Pb method in zircons it was calculated that 470 My the post-D1 and pre or syn-D2 granitoid intrusion occurred. This alloes to relate the main phhase of deformation D2 to the Guandacol Orogenic Phase (Late Arenig-Llanvirn)