IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
artículos
Título:
The oldest Ordovician foraminifers (Oepikodus evae conodont Zone) from South America
Autor/es:
NESTELL, G. P; HEREDIA S.E; BERESI M.S. ; GONZALEZ, M.
Revista:
GEOBIOS
Editorial:
ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
Referencias:
Año: 2011 vol. 44 p. 601 - 601
ISSN:
0016-6995
Resumen:
The oldest Ordovician foraminifers (Oepikodus evae conodont Zone) from South America Nestell, G. P.¹, Heredia, S.², Mestre, A.², Beresi, M.³ and González, M.² 1 Department of Earth and Environmental Sciences, University of Texas at Arlington,  Texas 76019, USA; Faculty of Geology, St. Petersburg State University, St Petersburg, Russia; email: gnestell@uta.edu 2 CONICET- Instituto de Investigaciones Mineras, Universidad Nacional de San Juan, Argentina; e-mails: sheredia@unsj.edu.ar; amestre@unsj.edu.ar 3 CONICET – Centro Cientifico Tecnologico Mendoza. Avenida Ruiz Leal (5501) Mendoza, Argentina; e-mail: mberesi@mendoza-conicet.gob.ar Abstract The oldest foraminifers of the monothalamous genus Amphitremoida Amphitremoida longa Nestell and Tolmacheva and A. laevis Nestell and Tolmacheva are found in the San  Juan Formation together with the conodonts of the Oepikodus evae Zone of the Floian, the second stage of the Lower Ordovician, in the Salagasta 2 section, southern Precordillera, Argentina. These discoveries also represent the oldest record for  foraminifers in South America. The foraminifers, species, of which were originally described from the Lower Ordovician of northwestern Russia, are found in shallow high energy carbonate platform deposits in the Precordillera with a North Atlantic province conodont fauna. The carbonate sequence of the San Juan Formation in the Salagasta  region is interpreted as a succession ranging from shallower tidal deposits to carbonate crinoidal shoaling bar deposits.  Keywords: Foraminifers, Conodonts, Lower Ordovician, Precordillera, Argentina