Structural geology and tectonics in the southern extent of the Agrio Fold and Thrust Belt, Neuquen Basin, Argentina

The Agrio Fold and Thrust Belt, in Northern Patagonia, Argentina is a world class example of an inversion driven fold belt. In the southern part of this folded belt, the surface mapping indicates that the inversion of the inherited geometries of the extensional system affected the thick-skinned region or Internal Domain. The Internal Domain comprises broad synclines and anticlines that are obliquely oriented relative to the main NNW-SSE and N-S trends of tight folds in the eastern, thin-skinned region or External Domain. This dichotomy in structural domains is also marked by the contrasting orientation of the P-axes (local maximum paleocompression directions) derived from fault-slip analysis. The subsurface interpretation of the transition between these two structural regions indicates how the continued inversion of the Internal Domain is also responsible for the subsequent and profuse tectonic wedging developed in the External Domain.