Constraining Andean Propagation of Exhumation at the Limit of the Eastern Cordillera, NW Argentina, Using Low?Temperature Thermochronology in a Structural Context

Within the Central Andes of NW Argentina, spatiotemporal distribution and style deformation is strongly influenced by pre-Cenozoic heterogeneities, mostly related to Salta rift extension in Cretaceous. At enigmatic junction thin-skinned Subandean belt thick-skinned Santa Barbara System, Tilcara Range adjacent San Lucas block, located within Eastern Cordillera, show thermochronological field evidence multiple exhumation events. Mesozoic (140-115 Ma), pre-Andean basement highs constrained unconformities between syn-rift strata, as well zircon (U-Th-Sm)/He cooling ages. Cenozoic Andean quantified apatite fission track ages, which were reset Late Cretaceous Miocene. These data that westernmost began exhuming late Oligocene-early Miocene (26-16 after propagated border Cordillera middle (22-10 Ma). The onset rapid east Range, occurred (10-8 Ma) its western part, Miocene-early Pliocene (6-4 eastern part. Internal disturbing age patterns, predates propagation exhumation. here presented low-temperature thermochronology set thus quantifies multi-phase history Argentina constrains timing structural transition zone.