Basin evolution as reflected by Miocene palynomorphs from the Chinches Formation, Frontal Cordillera (32º S), San Juan province, Argentina.

OTTONE, E.G.; BARREDA, V. D.; PEREZ, D.J.

REVISTA ESPANOLA DE MICROPALEONTOLOGIA

Instituto Tecnológico Geominero

Lugar: Madrid; Año: 1998 vol. 30 p. 35 - 47

0556-655X

Palynological data from the Miocene Chinches Formation, Eastern Espinacito Range, Frontal Cordillera (32°S)m San Juan Province, Argentina, provide a new information on the palaeogeographic evolution of Tertiary basins from southern South America. The palynoflora mainly reflects contributions of herbaceous and shrubby elements together with chlorococcaleans, scarce microforaminifera and dinoflagellate cysts, suggesting that a brackish marsh developed in a relatively dry climate. Miocene sea-waters apparently progressed from the southeast to the area also occupying the southern Grande River región. Tectonic controls on the marine transgressive event are briefly discussed.