Resumo

MARQUILLAS, R.; DEL PAPA, C.; SABINO, I.  e  HEREDIA, J.. The K/T boundary prospecting in the Northwest Basin, Argentina. Rev. Asoc. Geol. Argent. [online]. 2003, vol.58, n.2, pp.271-274. ISSN 0004-4822.

An 8 m-thick section has preliminary been selected in the Yacoraite Formation as favorable for prospecting the K/T boundary in the Salta Group (Neocomian-Eocene) where the position of the limit is still uncertain. Detailed research took place in El Chorro creek in the Metán sub-basin. This place was selected based on regional geological and paleontological evidence and stratigraphic-sedimentologic studies. Detailed work includes geochemical analysis, mineralogy and sedimentology of carbonates and clastic rocks, with the help of scarce information from the fauna and flora present in the succession. To date, anomalies of siderophile elements (Cr, Ni, Co) among others have been detected in coincidence with abrupt changes in sedimentary facies and microfacies, particulary a decrease and replacement of normal limestone facies by siliciclastic ones.

Palavras-chave : K/T boundary; Yacoraite Formation; Salta Group; Northwest Argentina.

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