C-O ISOTOPES OF THE EDIACARIAN LOMA NEGRA FOMRATION, DIAGENETIC IMPLICATIONS: BARKER AREA, TANDILIA SYSTEM, ARGENTINA.

LUCÍA E. GÓMEZ PERAL, ALCIDES N. SIAL, DANIEL G. POIRÉ Y MARIA JULIA ARROUY

Mendoza

Congreso; 18 th International Sedimentological Congress; 2010

International Asssociation of Sedimentologists

C-O ISOTOPES OF THE EDIACARIAN LOMA NEGRA FOMRATION, DIAGENETIC IMPLICATIONS: BARKER AREA, TANDILIA SYSTEM, ARGENTINA. LUCÍA E. GÓMEZ PERAL*, ALCIDES N. SIAL**, DANIEL G. POIRÉ*, & JULIA ARROUY* *Centro de Investigaciones Geológicas - CONICET-UNLP – Argentina ** Universidad de Pernambuco, Recife, Brazil The Neoporterozoic fill of the Tandilia Basin is exposed in Olavarría and Barker-San Manuel areas and this sedimentary succession is composed of the Villa Mónica, Cerro Largo, Las Aguilas, Olavarría and Loma Negra formations (Sierras Bayas Group) and the Cerro Negro Formation, (Spalletti and Poiré, 2005). On top of the Sierras Bayas Group a regional unconformity is recognized called Barker Surface and could be linked to Gaskiers glaciation, considering the Loma Negra Formation age (580-590Ma) obtained from global δ13C and 87Sr/86Sr trends and supported by Cloudina. Carbon and oxygen isotopic data, combined with a detailed diagenetic study, obtained from undeformed and unmetamorphosed limestone, provide a new record of isotopic stratigraphic variations useful for regional and global correlations.