A CHASICOAN (LATE MIOCENE) VERTEBRATE ASSEMBLAGE FROM CERRO AZUL FORMATION, CENTRAL ARGENTINA. GEOMORPHOLOGICAL AND BIOCHRONOLOGICAL CONSIDERATIONS

MONTALVO, CLAUDIA I.; TOMASSINI, RODRIGO L.; SOSTILLO, RENATA; CERDEÑO, ESPERANZA; VERZI, D.; VISCONTI, G.; FOLGUERA, A.; SCHMIDT, GABRIELA I.

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2019

0895-9811

The Cerro Azul Formation, mainly extended in the center and east of La Pampa Province (Argentina), has provided interesting faunal assemblages assigned to the late Miocene (mostly Huayquerian). However, the fauna recovered from several localities with outcrops of the Cerro Azul Formation were preliminarily assigned to the Chasicoan (late Miocene). One of them, based on the presence of the Ctenomyidae rodent Chasichimys bonaerense was Cerro La Bota, placed at the southwestern limit of the Pampa Central Block. The revision of the vertebrate assemblage from Cerro La Bota, as well as new geomorphologic interpretations of the Cerro Azul Formation in the area, confirms the previous assignation to the Chasicoan age. Cerro La Bota shares 18 taxa with Arroyo Chasicó in Buenos Aires Province; several of them are mentioned for the first time for Cerro Azul Formation in La Pampa Province. The assignation of this fauna to Chasicoan agrees with the geomorphological data, which indicate that Cerro La Bota is included in a topographic step linked to the Valle Daza?Lonco Vaca fault that exposed the older levels of the Cerro Azul Formation in the area.