Biostratigraphy of Ordovician sequences from Alfarcito area, Tilcara, Eastern Cordillera of Jujuy, Argentina

ZEBALLO, F.J.; ALBANESI, G.L.; ORTEGA, G.; TORTELLO, M.F.

Serie Correlación Geológica

INSUGEO

Año: 2003 vol. 17 p. 161 - 166

1514-4186

Present study is aimed to propose a comprehensive biostratigraphy and correlation of Lower Paleozoic sequences cropping out in the Alfarcito area of Eastern Cordillera, Northwestern Argentina.Previous paleontological works from these sequences were devoted to trilobites (Harrington and Leanza, 1957). Subsequently, López and Nullo (1969) presented the geology of the area, and Moya (1988) described the stratigraphy of the Rupasca Creek, among other Lower Ordovician sections of Eastern Cordillera.About 400 trilobite samples, 57 graptolite samples, and 23 carbonate samples for conodonts (ca. 2 kg each, on average, yielding 3000 elements in total) were collected from the whole Cambro-Ordovician succession, allowing for the proposal of a composite biostratigraphic scheme. Registered conodonts show a Color Alteration Index 3 that corresponds to 110º-200º overburden paleotemperatures (Epstein et al., 1977). Fossil materials are deposited in the Paleontological Museum, National University of Córdoba (under CORD-MP and CORD-PZ repository abbreviations). Authors acknowledge supports by CONICET and National University of Córdoba, Argentina, for current research.