Evolution of a high-grade ductile shear zone through the analysis of textural and compositional changes: an example from the Famatinian orogen, Sierra de La Huerta, San Juan, Argentina

CASTRO DE MACHUCA, B.; DELPINO, S.; MOGESSIE, A.; PONTORIERO, S; PREVILEY, L; BJERG, E. A.

Río Cuarto, Córdoba

Congreso; XIV Reunión de Microtectónica; 2009

Universidad Nacional de Río Cuarto

A lower granulite to upper amphibolite facies ductile shear zone with NNE trending and E dipping mylonitic foliation has been recognized in the Arenosa Creek, Sierra de La Huerta, province of San Juan, affecting an outcrop of quartzose metagabbro-metadiorite (PI-Hbl-Bt-Qtz±Cpx±Opx-opaques) which is part of the Famatinian magmatic arc of the Western Sierras Pampeanas. Kinematic analysis of the Arenosa Creek Shear Zone (ACSZ) indicates reverse-sense of shear with a minor component of dextral displacement. This is compatible with the kinematics of other ductile deformation zones in the area, collectively forming a network.