Associações de Foraminíferos e Padrões Sedimentares da Plataforma Externa do Rio Grande do Norte, NE-Brasil

Abstract

Foraminifera as tools have contributed to the investigation of sedimentary processes, carbonate productivity, water quality, nutrient intakes and environmental health of continental shelves. Here we show how foraminiferal associations are influenced by nutrients and abiotic factors that control the carbonate production in the modern outer shelf of Rio Grande do Norte, in the region of Açu Reefs. Granulometric analysis, CaCO3 and organic matter content allowed us to identify six sedimentary facies. Quantitative and qualitative biologic data were used on the univariate and multivariate statistical analyzes. The presence of the planktonic foraminiferal species Globigerina rubra, and the benthic species 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. It was observed that the diversity of symbiotic organisms is related to carbonate production and the pristine shelf environment. These foraminiferal species indicate the occurrence of oceanic phenomena under the influence of Tropical Gyre and resurgence.