Ordovician faunal turnover in the Argentine Precordillera

SÁNCHEZ, T.M.; CARRERA, M.G.; WAISFELD, B.G.

ACTA UNIVERSITATIS CAROLINAE. GEOLOGICA

Univerzita Karlova

Lugar: Praga; Año: 1999 vol. 43 p. 479 - 481

0001-7132

In the Argentine Precordillera, Ordovician strata are composed of a succession of carbonate and siliciclastic rocks raning in age from the Tremadoc to the Ashgill. In recent years, numerous taxonomic studies have greatly increased the knowledge of the Precordillera faunas. In addition, recent contributions have analyzed paleoecologic and dynamc aspects of Lower Ordovician assemblages. The analysis in mainly based on trilobites and brachiopods as they are recordedthroughout the entire period and in almost succession. On the basis of the faunal content, 7 biotic intervals are recognized since the Arenig: early Arenig, middle Arenig, late Arenig, early Llanvirn, late Llanvirn-early Caradoc,late Caradoc-Ashgill and late Ashgill (Hirnantian).