Crustal Deformation of a High‐Altitude Salar: Evidence of Quaternary Strike‐Slip Tectonics in the Salar de Antofalla (26°20′S)

The Salar de Antofalla, located in the southern Puna Plateau of northwestern Argentina, provides a key locality to investigate the late Cenozoic deformation in high‐elevation endorheic basins. We integrate detailed geological–structural mapping, high‐resolution UAV‐derived topography, optical luminescence dating, and kinematic analysis of mesoscopic fault‐slip data to characterize active deformation along the Acazoque and Mojones fault systems. We document ongoing dextral strike‐slip activity affecting both alluvial and evaporitic deposits. In particular, segments of the Acazoque Fault System exhibit dextral–contractional and dextral–extensional kinematics, generating rhomboid‐shaped sag ponds and pressure lobes consistent with pull‐apart basin development. The Mojones Fault System, located ∼10 km to the south, shows similar dextral kinematics, displacing Late Pleistocene alluvial deposits dated between 52 and 26 kyr. Horizontal offsets of 10–30 m, yield minimum slip rates of approximately 0.2–1 mm/yr. Paleostrain reconstructions indicate E–W to NE–SW contraction and N–S to NW–SE extension, consistent with the regional Pliocene–Quaternary strike‐slip stress field previously proposed for the southern Puna. These results demonstrate for the first time that the Salar de Antofalla is actively deforming in response to a dextral strike‐slip system, and the fault segmentation directly controls the development of localized depocenters within the salar.