- journal_title：Journal of the Geological Society
- Contributor：VERóNICA OLIVEROS ; LUIS AGUIRRE ; DIEGO MORATA ; ANTONIO SIMONETTI ; MARIO VERGARA ; MAURICIO BELMAR ; SERGIO CALDERóN
- Publisher：Geological Society of London
- Date：2008-
- Format：text/html
- Language：en
- Identifier：10.1144/0016-76492007-113
- journal_abbrev：Journal of the Geological Society
- issn：0016-7649
- volume：165
- issue：2
- firstpage：579
- section：Original Article
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.