Controles precuyanos en la estructura de cuenca Neuquina.

CRISTALLINI, E.O.; TOMEZZOLI, R.; PANDO, G.; GAZZERA, C; MARTINEZ, J.M.; QUIROGA, J.; BUHLER, M; BECHIS, F.; BARREDO, S.; ZAMBRANO, O.

Revista de la Asociación Geológica Argentina

Asociación Geológica Argentina

Lugar: Buenos Aires; Año: 2009 p. 248 - 264

0004-4822

An integrated map of precuyan structure of the eastern region of the Neuquén basin is presented. The principal grabens, half-grabens, faults and transference zones developed to the south of Colorado River are mapped based on 2D and 3D seismic information and previous published works. The general direction of Upper Triassic – Lower Jurassic normal faults is NW-SE. However, two distinct populations can be differentiated. The first (NW) has directions higher than azimuth 130°, and in general, accommodates the mayor and deepest gabens and half-grabens (e.g. Entre Lomas y Estancia Vieja). The directions of the second population faults (WNW) are lower than azimuth 110° and in general are related with small and shallower troughs (e.g. Loma La Lata, Agua de Cajón, Lindero Atravesado, Bandurria, etc.). The interaction between both fault populations is not easy to see, however, in some sectors could be seen that the second (WNW) cuts to the first (NW). Distributed over the hole region there are Upper Jurassic – Cretacic normal faults. These faults are nucleated over the oldest precuyan (Tr-J) faults and over the hinges of the half-grabens. In this work, these normal faults are explained as developed because of the tension due to differential subsidence of the grabens and half-graben infill. These J-K normal faults has general NW directions and are developed parallel to the NW precuyan faults population and en echelon over the WNW population.