Anatectic granites of the Sierras Pampeanas from Córdoba (Argentina)U-Pb SHRIMP and zircon trace element LA-ICP-MS study of diachronic metamorphism and crystallization
- Fernando Javier D Eramo 1
- José Julián Esteban Guzmán 2
- Manuel Demartis 1
- Jorge Enrique Coniglio 1
- Eugenio Aragón 3
- Lucio Pedro Pinotti 1
- 1 Instituto de Ciencias de la Tierra, Biodiversidad y Ambiente (ICBIA) (UNRC-CONICET). Córdoba, Argentina
- 2 Departamento de Geodinámica, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU
- 3 Universidad Nacional de la Plata, Argentina
ISSN: 0213-683X
Année de publication: 2020
Número: 68
Pages: 27-30
Type: Article
D'autres publications dans: Geogaceta
Résumé
In this contribution we present new U-Pb SHRIMP ages and in situ LA-ICP-MS trace element geochemistry of zircon crystals from the Río de los Sauces anatectic granite, Córdoba, Argentina. Nota-ble difference in texture and composition allowed us to identify two zircon populations in a single granite sample that are interpreted as reflecting metamorphic and igneous origins. Zircons regarded as restitic crystals entrained during the melt segregation yielded a slightly older concordia age of 537.1 ± 4.8 Ma (2σ) than those inter-preted as igneous, dated at 529 ± 6 (2σ) Ma. Inherited metamorphic zircons are interpreted to represent solid-state growth during high temperature metamorphism of the Pampean orogeny at the onset of the anatexis or metamorphic peak. By contrast, igneous zircons would record the crystallization age of Zr within the Río de los Sauces granite. The textural, compositional and geochronological data of both zircon populations suggest that the inception of the anatexis, the melt segregation and crystallization occurred during a short pe-riod of time of 8 my.