Chemostratigraphy and diagenetic constraints on Neoproterozoic carbonate successions from the Sierras Bayas Group, Tandilia System, Argentina

GÓMEZ PERAL, L., POIRÉ, D.G., ZIMMERMANN U. AND STRAUSS H

San Pablo, Brasil

Simposio; 1st Symposium of the IGCP -478 proyect; 2004

Universidad de San Pablo

Geochemical data, using Mn/Sr, Fe/Sr and Ca/Sr combined with stable isotope data point to a significant diagenetic alteration. Loma Negra Formation is constituted by homogeneous non-luminescent micritic limestones, which selected element data indicate a primary signature undisturbed by diagenetic processes. The Villa Mónica Formation can be placed between 800 and 900 Ma, based on Rb/Sr radimetric data and stromatolites. Loma Negra Formation fit in global range age ~580-590 Ma, which are of regional importance as they represent the eastern part of a possible Vendian basin of south-western Gondwana. In the same sense, Loma Negra Formation isotopic signature is consistent with those data reported from the Vendian Polanco Formation.