Isotopic strontium, carbon and oxygen study on neoproterozoic Marbles from Sierra de Umango, Andean foreland, Argentina - Varela, Ricardo; Valencio, S.; Ramos, A.; Sato, Kei; Gonzalez, Pablo D.; Panarello, H.; Roverano, D. (South American Symposium on Isotope Geology, 2001)