INTERPRETAÇÃO DO TESTEMUNHO T-101, (32°05'S; 47°35'W) COM BASE EM NANOFÓSSEIS CALCÁRIOS - CONE DO RIO GRANDE, RIO GRANDE DO SUL, BRASIL

Abstract

The present paper refers to the study of the calcareous nannofossils of the piston core T-101, placed in the Rio Grande do Sul Continental Elevation, latitude 32°05'S and longitude 47°35'W. The piston core presents 670cm of length and was obtained in a depth of 3.200m in the Rio Grande Cone area, during the accomplishment of the oceanography campaign GEOMAR VII, 1976. The analysis of these microfossils shows that they do not have a sequential distribution along the piston core, occurring concentrated at 670cm, 620cm and 580cm of the base and at 15cm of the top. Through the taxonomic identification of these microfossils, reworked material was detected in the base of the piston core mixing the early Pleistocene species with the Pliocene species. In the top, exist an assemblage of late Pleistocene. In the interval 580-15cm, calcareous nannofossils doesn't exist. Palaeoecologic and palaeoenvironmental inferences were presented. As the same time, took place the correlation of the top of the Zone Calcidiscus macintyrei of Gartner, 1977 of lower Pleistocene with the medium part of the magnetostratigraphic Matuyama unit and of the Zone Emiliania huxleyi of Gartner, 1977 with the superior part of the Brunhes unit.