Facies de Alto Grado de la Formación Cushamen en Aguada del Pajarito, Macizo Norpatagónico. Provincia de Chubut

CERREDO, M.E.,; PARICA, C.A. ; REMESAL, M. B

Buenos Aires

Congreso; 6º Congreso de Mineralogía y Metalogenia; 2002

Departamento Ciencias Geológicas - FCEN - UBA

ABSTRACT: THE HIGH-GRADE METAMORPHIC ROCKS OF CUSHAMEN FM. AT AGUADA DEL PAJARITO. NORTHPATAGONIAN MASSIF. CHUBUT PROVINCE The metamorphic series of Cushamen Formation at Aguada del Pajarito is composed of biotite (± garnet) schists with interlayered amphibolites. Two ductile deformation phases were recognized, each accompanied by foliation development (St and S2). The second deformation is characterized by the development of the main foliation (S2) which is axial plane foliation of relic Fi folds preserved in relic, folded leucocratic veins. The observed equilibrium assemblages in both in schists and amphibolites suggest amphibolite fades conditions for the climax of regional metamorphism which would have been synchronous with the second deformation. A later decompressive path could be inferred from reaction textures.