Search

The present paper deals with the description of the first remains of the Family Mesotheriidae in the Quebrada Fiera locality. The fauna from Quebrada Fiera comes from sediments nowadays considered to represent the base of the Agua de la Piedra Formation. The recovered faunal assemblage includes typical elements of the Deseadan Age (late Oligocene), shared with both Patagonian and lower latitude associations (e.g., Salla, Bolivia). A unique specimen of Mesotheriidae has been recovered after several field seasons since 2006. It is a palatal portion in two fragments, one bearing the I1 and the other with left P4-M2 and right M1-2. Morfological and metrical features of this material reveal a taxon much closer to the Patagonian mesotheriid species Trachytherus spegazzinianus than to the Bolivian taxa, T. alloxus and T. subandinus, and it is determined as Trachytherus cf. T. spegazzinianus. Its presence in Mendoza fills a gap in the expected geographical distribution of this mesotheriid, as it was also recorded in the Bolivian site of Lacayani. The scanty record of mesotheriids in Quebrada Fiera contrasts with Salla and Patagonian localities. Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina

A preliminar palynostratigraphic framework is proposed for Cenozoic deposits cropping out in the southern San Jorge Gulf area, Santa Cruz Province, Argentina. Pollen and spores assemblages and associated dinoflagellate cysts recovered from three sections, Mazarredo, Punta Nava and El Faro, were analysed. On the basis of the palynological content two units were recognised and inforrnally named: Unit 1 and Unit 2. Unit 1, represented in Mazarredo and Punta Nava sections, was assigned to the Late Oligocene. The paleoenvironment was identified as a lagoon for the former and inner shelf for the latter. The underlying Unit 2, comprising the top of Punta Nava and El Faro sections, is onsidered to be Early Miocene in age and deposited in a sublitoral to coastal environment. It can be correlated with the Cheuque Formation (Chubut Province). Both dinoflagellate cyst and adjacent land derived pollen and spores suggest humid and warm -temperate climatic conditions for the Late Oligocene and a slight deterioration for the Early Miocene. Fil: Barreda, Viviana Dora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Invest.en Rec.geologicos (i); Argentina Fil: Palamarczuk, Susana Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Invest.en Rec.geologicos (i); Argentina

The palynomorph content of surface samples frorn two sections –Monte Observación and Monte Entrada- crapping out at the Atlantic coast in Santa Cruz Pravince is analysed herein. Poorly to fairly well preserved terrestrial and marine assemblages were recovered. The abundance and diversity of the palynoflora show strang paleoenviranmental control, fluctuating from moderate to low as a reflection of near shore to inner neritic depositional conditions. A Miocene (probably Early Miocene) age is assigned to the sections on the basis of the stratigraphic range of selected species previously recorded in nearby areas. The sections can be partly correlated, a1though the uppermost levels of the Monte Observación section, mostly deposited in a freshwater environment, were not encountered in Monte Entrada section. These upper levels represent the transition to the overlying continental Santa Cruz Forrnation. A tectonic reactivation event was recognised in both sections, characterised by a suddenincrease of reworked palynomorphs, mostly frorn Upper Cretaceous deposits from the source area of the sediments. Fil: Barreda, Viviana Dora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Recursos Geológicos (i); Argentina Fil: Palamarczuk, Susana Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Recursos Geológicos (i); Argentina