CARACTERIZAÇÃO SEDIMENTAR E ASSEMBLEIAS DE FORAMINÍFEROS BENTÔNICOS DA PLATAFORMA EXTERNA EQUATORIAL, ADJACENTE AO ESTADO DO RIO GRANDE DO NORTE, BRASIL:

Studies on mixed carbonatic and siliciclastic sedimentation on the Brazilian continental shelf have been used Foraminifera as bioindicators of carbonate productivity, marine currents, nutrient intakes, and environmental health. This work aim to investigate the recent sedimentary coverage and the Foraminifera assemblages of the equatorial outer shelf of Rio Grande do Norte State, between the Apodi-Mossoro and Piranhas-Acu incised valleys to understand the nutrient distribution and carbonate production. Statistical methods were used for the biotic data, in quantitative and qualitative values. granulometric analysis, CaCO3, and organic matter contents allowed to identify six sedimentary facies. The presence of Globigerina rubra, Quinqueloculina patagonica, and Peneroplis pertussus is related to the intrusion of ocean currents over the shelf break. The presence of Buccella peruviana is correlated with high CaCO3 and organic matter contents.  The species of foraminifera mentioned above may indicate occurrence of oceanic phenomena such as tropical Gyre and upwelling. Diversity of symbiotic organisms and their correlation to abiotic are related to carbonate production and the pristine shelf environment.