Evolución Tectónica de La Fosa de Loncopué: Estructura del depocentro Cuaternario del Huecú y su relación con la sedimentación y el volcanismo

ROJAS VERA, EMILIO; FOLGUERA, ANDRES; GIMENEZ, MARIO E.; MARTINEZ, M PATRICIA; RUÍZ, FANCISCO; RAMOS, VICTOR

REVISTA DE LA ASOCIACIÓN GEOLÓGICA ARGENTINA

ASOCIACIÓN GEOLÓGICA ARGENTINA

Lugar: Buenos Aires; Año: 2009 vol. 64 p. 214 - 230

0004-4822

Abstract: Tectonic Evolution of the Loncopué trough: structure of the Quaternary Huecú depocentre and its relation whith the sedimentation and volcanism. The Huecú basin is located at the central part of the large Loncopué retroarc trough. Its volcanic, volcaniclastic, lacustrine and fluvial filling is directly related to neotectonic deformation in the area. The basaltic eruptions are reflecting the different pulses of activity associated with the development of extensional faults and tensional fractures. Geophysical potential methods have identified the participation of the basement of the Tertiary sequences in the extensional deformation that affected the area during the last 5 Mys. Neotectonic features in Quaternary volcanic sequences suggest the persistence of subsidence mechanisms that created the Huecú basin. These faults are directly connected to the basement segmentation determined by gravimetric and magnetometric studies. The historical floods that were produced since the río Agrio damming, related to fissural eruptions in this basin, demonstrate the high probability that retroarc volcanic eruptions were repited. The recognition of flooded areas that are forming the last sedimentary levels in the Huecú basin allow to estimate potential areas of active retroarc spreading in the Neuquén area associated with neotectonic and seismic processes.