Thermochronology of the Ventana Ranges and Claromecó Basin, Argentina: Record of Gondwana breakup and South Atlantic passive margin dynamics

• Published in: Journal of South American earth sciences 2021-01, Vol.105, p.102965, Article 102965
• Main Authors: Guadalupe, Arzadún, Pablo, Lovecchio Juan, Raúl, Becchio, Javier, Uriz Norberto, Carlos, Cingolani, Belén, Febbo María, Roberto, Hernandez, Nestor, Bolatti, Pedro, Kress
• Format: Article
• Language: English
• Subjects: Claromecó basin; Colorado basin; Gondwana breakup; Thermochronology; Ventana ranges
• ISSN: 0895-9811; 1873-0647
• DOI: 10.1016/j.jsames.2020.102965

The Ventana Ranges and the neighboring Claromecó basin display multiple extensional and compressional tectonic events throughout their Phanerozoic evolution. A passive continental margin setting during the early Paleozoic changed to a compressional system in the late Paleozoic, for which the Ventana Ranges are its fossilized fold and thrust belt and the Claromecó Basin, to the north-northeast, its associated foreland basin. The thermochronology study presented here and the cooling ages obtained for the Ventana Ranges are interpreted as a long-lived, probably multi-stage, exhumation event that occurred throughout the Mesozoic. The ZFT and AFT ages indicate that the Silurian, Devonian, Carboniferous and Permian units cooled during the Late Triassic to Early Jurassic (from 204.4 ± 18.8 to 146.5 ± 11.6 Ma). These ages, consistent with rifting events described for the neighboring Colorado basin (to the south-southeast), are interpreted as exhumation in the rift's northern flank. In the Claromecó Basin, a cooling event is indicated from the AFT PAZ data for the late Early Cretaceous (Barremian-Aptian, 125.8 ± 10.6 Ma), interpreted as a part of passive margin exhumation during the drift stage after the South Atlantic opening in the Valanginian-Hauterivian. The obtained ages indicate exhumation in the basin flank and are consistent with the different rifting events previously interpreted for Colorado basin. •The Ventana Ranges and Claromecó basin record an exhumation history coetaneous with the rifting history of the basin.•Most of the exhumation in the Ventana Ranges and Claromecó basin was achieved during the Mesozoic.•The Ventana Ranges display Late Triassic to Early Jurassic ZFT cooling ages, and Early to Late Jurassic AFT cooling ages.•Permian units in the Claromecó Basin display Jurassic ZFT cooling ages and Early Cretaceous AFT cooling ages.•A thickness of at least 2000 m of Permian succession was eroded from the top of the Tunas Fm during the Mesozoic exhumation.