Grenvillian basement and famatinian events of the Sierra de Umango (29 S): a review and new geochronological data - Varela, Ricardo; Basei, Miguel Angelo Stipp; Sato, Anna María; Gonzalez, Pablo D.; Siga Júnior, Oswaldo; Campos Neto, Mario da Costa; Cingolani, Carlos Alberto (South American Symposium on Isotope Geology, 2003)