Control estructural en el desarrollo de una concetración anómala de calderas en los Andes de Neuquén: Complejo Volcánico Pino Hachado (38º30´S-71ºO).

TUNSTALL, C. Y FOLGUERA A.

revista de la asociación geológica argentina

Asociación Geológica Argentina

Lugar: buenos aires; Año: 2005 vol. 60 p. 731 - 741

0004-4822

One of the most important concentrations of volcanic complexes in the entire Southern Andes developed during the last 5 Ma, is present at 38º30´S next to the drainage divide. These volcanic features, formed calderas and domic complexes which have been amalgamated in a volcanic plateau of 50 x 50 kilometers. Its origin is associated with young activity of one of the branches of the northern intra-arc Liquiñe-Ofqui fault system, as widespread Plio-Quaternary faulting is developed east of the volcanic arc. Moreover, quadrangular geometries in the volcanic complexes, as well as widespread linear controls in fissural monogenetic field, suggest that additional mechanisms, linked to basement structure, have defined the emplacement of such big volumes of magmas. Aeromagnetic data constitute a first approach to determine basement segmentation defined during ancient phases of crustal attenuation in the zone. Therefore, final geometry and distribution of the Pino Hachado volcanic complex (38º30´S-71ºW), even though related to Plio-Quaternary tectonics at the arc zone, are deeply influenced by basement structure.