Evolucion tectonica Andina entre las Sierras de Hualfin, Capillitas y extremo sur de Aconquija, Provincia de Catamarca.

SEGGIARO, R.; CAFFE, P.; BECCHIO, R.; GALLI, C.I.; ARNOSIO, M.; DA POIAN, G.

Asociacion Geologica Argentina Revista

Asociacion Geologica Argentina

Lugar: Buenos Aires; Año: 2014 vol. 74 p. 500 - 512

0004-4822

Andean tectonism of the Hualfín, Capillitas and southern Aconquija Ranges, Catamarca Province The northern Sierras Pampeanas in the Tucumán - Catamarca boundary are mainly composed of crystalline basement rocks, tilted by NE-SW strike faults that form part of the Aconquija and Tucumán lineaments. The Capillitas, Hualfín and Aconquija Ranges are separated by intermountain valleys filled with Tertiary volcanic and sedimentary rocks deposited unconformably over the crystalline basement. These units were affected by four different deformation events during the Andean orogenic cycle. The first one is associated to normal faults that controlled the deposition of the Hualfín Formation, evidenced by development of growth strata. During the second event, the Hualfín Formation was intensively folded and eroded prior to the deposition of the Farallón Negro Volcanic Complex (CVFN). The third event was transtensive and recorded by the Farallón Negro volcanic complex, with the development of normal faults and intraformational progressive uncomformities. This event is concordant with the initial stages of the volcanism in the region. In order to make a strain analysis of the fourth and last deformation event, kynematic indicators were measured on regional and minors faults. Results suggest dextral movements of faults and transpressive conditions. Mountain uplift and intrusion of subvolcanic rocks as well as ore deposition are related to these movements, e.g., in Cerro Atajo, Capillitas and Agua Rica. Transpressive conditions are still active today, as shown by recent debris avalanches and debris flow deposits associated to main faults.