FORAMINÍFEROS PALEOCENOS DEL ÁREA CARBONÍFERA DE RÍO TURBIO, PROVINCIA DE SANTA CRUZ, ARGENTINA

Abstract

"Fifty four species of foraminifera from the Palaeocene of Río Turbio area are described. The T-I36 and T-137 boreholes at the south of Río Turbio drilled the Cerro Dorotea Formation. Both boreholes yielded Late Palaeocene foraminifers with levels of abundant specimens concentrated above the Upper Coal Horizon (HCS) in the upper part of the Cerro Dorotea Formation. Buliminella isabelleana Camacho forma procera Huber, Nonionella ovata Brotzen and Anomalinoides perthensis (Parr) are dominant. The same species were also recorded in equivalent levels of the Filo de la Mina outcrops. The lower part of the Cerro Dorotea Formation outcropping in Filo de la Mina was barren. The T-137 and T-136 holes yielded foraminifers. The T- I37 provided two specimens of ""Discorbis"" mariae (Jones) from a carbonaceous clay level probably equivalent to the lower part of the Cerro Dorotea Formation. An equivalent level ofthe T-I36 borehole offered an assemblage dorninated by Alabamina sp. 1885 and Danian foraminifers. Excluding Buliminella isabelleana Camacho forma procera Huber, endemic from the Austral Basin and Antarctica, all species are cosmopolitan. The Danian and Late Palaeocene assemblages are characteristic of a shallow water coastal environment, stressed and reducing conditions."