The Andean retrowedge, located between 338S and 348S, lies in the transition region of the Pampean flat-slab subduction zone to the north and a normal subduction zone to the south. Neotectonic structures and shallow seismicity are very common north of this segment and become progressively less frequent southwards. The Frontal Cordillera and the Cerrilladas Pedemontanas are the main morphostructures involved in the Quaternary deformation of this region. The Frontal Cordillera is a thick-skinned fold-and-thrust belt uplifted since Late Miocene time. The Cerrilladas Pedemontanas are low-relief hills that represent the mild inversion of the Cuyo Triassic rift depocentre since Pliocene time. Middle Miocene-Holocene synorogenic strata cover the Cuyo basin and surrounding foreland areas. The Quaternary tectonic evolution of this area has been established through integration of new data from fieldwork in the Frontal Cordillera piedmont with subsurface information and previously published data. Mean Late Pleistocene uplift rates ranging between 0.21 and 0.92 mm a 21 and earthquake minimum moment magnitudes (M w ) of c. 6.4-6.7 have been estimated for the morphostructural units analysed in this manuscript.

Quaternary tectonics along oblique deformation zones in the Central Andean retro-wedge between 318 8 8 8 830 ′ S and 358 8 8 8 8SAbstract: The distribution of the Quaternary deformation in the outer retro-wedge of the Andes (31830 ′ -358S) is controlled by the subduction geometry, the position of the structural front, and the location of oblique pre-Cenozoic mechanical anisotropies. In the Southern Precordillera, Quaternary structures tend to group along the Barreal-Las Peñas deformation zone with a NW to NNW trend. This Cenozoic belt (31830 ′ -32840 ′ S) developed on the northern segment of the Triassic Cuyo Basin and broadened laterally during the Quaternary. New radiocarbon ages on dam deposits confirm Holocene tectonic activity on the northwestern edge. The oldest ages of dam deposits are 5810 + 90 a BP (Cabeceras Creek) and 810 + 50 a BP (Dolores Creek). Palaeoseismological and seismic data suggest active tectonic growth on the NW and SE extremes. Quaternary tectonics has contributed to modifying the relief along this oblique belt. This contribution is evident from the tectonic uplift of blocks (minimum 90-120 m in the Barreal block), the initial development of intermontane basins (Pampa de los Burros Basin), the Quaternary rejuvenation of tectonic depressions (at least 32-37 m of tectonic subsidence in the Vizcacheras half-graben) and the incipient development of low-relief morphotectonic units by soft-linkage of Quaternary structures.