ISOTOPE STRATIGRAPHIC EVIDENCE FOR A NEOPROTEROZOIC CAP CARBONATE IN SIERRAS BAYAS GROUP, TANDILIA SYSTEM, ARGENTINA

LUCIA GOMEZ PERAL; ALCIDES N. SIAL, ALAN J. KAUFMAN AND DANIEL G. POIRE

Medellin

Simposio; South American Symposium on Isotope Geology; 2012

Corpogemmas

C-, O-, Sr-isotope data for undeformed and unmetamorphosed dolostones (40-80m thick) from the basal section of the Sierras Bayas Group, Tandilia system, Argentina, provide new useful information for regional and global correlations. In this sense, the model of its diagenetic evolution is consistent with trends of primary marine origin.Detailed chemostratigraphic correlations between four complete profiles of dolostones of the Villa Mónica Formation allow to identify three sections, from base to top, regarding C-O trends, sedimentary facies in its marine paleoenvironmental, and redox context. C-and O- isotope excursions are related to sea-level fall from deeper to shallow facies to a marine stromatolitic platform.