Mid-Cenozoic SHRIMP U-Pb detrital zircon ages from metasedimentary rocks in the North Patagonian Andes of Aysén, Chile
- Autor Institucional:
- Lugar de Edición:
- Fuente o Serie:
- Andean Geology
- Año, Volumen y Número:
- 2021, Vol 48, No 1
- Número de serie:
- 1
- Páginas:
- pp.54-74
- Escala:
- Fecha:
- 2021
- Descripción física:
- Resumen:
- Previously undated low-grade metamorphic rocks from the Puerto Cisnes-Queulat area (44°30’ S) contain detrital zircons of mid-Oligocene age (ca. 28 Ma). Their outcrops represent the easternmost occurrence of the late Oligocene to early Miocene marine volcano-sedimentary Traiguén Formation; previous correlation with the Paleozoic metamorphic basement of this sector of the North Patagonian Andes is thus refuted. A similar age and provenance were obtained for a paraconglomerate bed of the La Junta Formation ca. 80 km to the north, which is thought to represent a high-energy lateral facies variation of the Traiguén Formation. Miocene plutonic rocks of the North Patagonian Batholith intruded these metasedimentary rocks, generating a contact metamorphic aureole that reaches biotite grade and overprints a previous metamorphic fabric probably formed during closure of the Traiguén Basin. Similar young ages for metamorphic rocks located immediately west of the Liquiñe-Ofqui Fault Zone 300 km north, near Ayacara, suggest a regional pattern of earliest Neogene metamorphism and rapid exhumation in this segment of the Patagonian Andes.
- Editor:
- Descripción:
- URI:
- https://repositorio.sernageomin.cl/handle/0104/24674
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