OLIVEROS, VERóNICA AGUIRRE, LUIS MORATA, DIEGO SIMONETTI, ANTONIO VERGARA, MARIO BELMAR, MAURICIO CALDERóN, SERGIO Geochronology of very low-grade Mesozoic Andean metabasites; an approach through the K–Ar, <sup>40</sup>Ar/<sup>39</sup>Ar and U–Pb LA-MC-ICP-MS methods <p>Multiple geochronological methods using different metamorphic minerals were combined to date the regional, very low-grade metamorphism affecting Upper Jurassic–Lower Cretaceous volcano-sedimentary successions in the Andes of central Chile. Early Late Cretaceous metamorphic ages (between 82 and 108 Ma) were obtained by the K–Ar and U–Pb methods for celadonite and titanite. A much younger thermal event is responsible for actinolite formation at 8 Ma, most probably related to the intrusion of proximal Miocene granitoids. Previous models for the metamorphism should be reinterpreted taking into account the absence of a greenschist-facies event. The combination of different metamorphic minerals and chronometers is regarded as a powerful analytical tool to date the very low-grade metamorphism associated with the Mesozoic extensional regime developed within the Andes. </p> metamorphism;Cretaceous;Previous models;Miocene granitoids;8 Ma;method;Mesozoic extensional regime;actinolite formation;mineral;And;Ar;108 Ma;Geology 2016-06-21
    https://geolsoc.figshare.com/articles/dataset/Geochronology_of_very_low-grade_Mesozoic_Andean_metabasites_an_approach_through_the_K_Ar_sup_40_sup_Ar_sup_39_sup_Ar_and_U_Pb_LA-MC-ICP-MS_methods/3454514
10.6084/m9.figshare.3454514.v1