Triassic continental oblique rifting controlled by Paleozoic structural grain: The Puesto Viejo Basin, western Argentina

摘要

The aim of the present study was to characterize in detail the Triassic structures of the Puesto Viejo Basin in San Rafael Block, western Argentina, and to establish the role of these previous structures in the development of the rift. The structural analysis of this basin showed the important effect of pre-existing faults on the geometries of evolving fault systems. The analysis also showed that the distribution of the basin boundary NNW-SSE faults was conditioned by the structural grain and by the disposition of the NW-SE internal structures, a fact consistent with a NE-SW extensional regime. The kinematics of the structures can be explained by a low to moderate obliquity and a high partitioned deformation. The basin geometry, its tectonoestratigraphic evolution, and the kinematic analysis of the faults allow defining it as an extensional basin, which can be characterized as an oblique rift.