Aspectos Morfológicos e sedimentológicos de uma paleoduna localizada na porção centro-leste do estado de Roraima (RR).

Abstract

Although aeolian dunes are better studied in coastal regions, the intracontinental aeolian dunes still needs classificatory and comparative studies. In the north of Amazon, sandy paleodunes fields with dozend kilometers of extension have been identified by remote sensing products in isolated areas in the states of Amazonas and Roraima and their genesis has been associated with aeolian activity in the driest periods of the Last Glacial Maximum.The most accessible paleodune, focus of this study, is located southwest of the city Boa Vista (Roraima), in the patch between BR-174 and Branco River. Actually is the one that presents the most number of available geochronological data, which allowed this positioning in Late Pleistocene – Holocene. Morphological, sedimentological and microtexture data of this paleodune helped to understand the active depositional processes, as well as their differentiation of the associated deposits of the Boa Vista and alluvial deposits allowed their association wih the main paleoclimatic events that operated in Amazonia and South America in the Pleistocene Late – Holocene.