Aplicabilidade dos foraminíferos bentônicos na restituição paleo-ambiental e no impacto antrópico da laguna de Saquarema, Rio de Janeiro.

Abstract

Three cores were drilled at the Saquarema Lagoon, Rio de Janeiro, to evaluate the foraminifera assemblage distribution associated with sedimentological features, in order to perform a paleoenvironmental reconstruction. In cores T1 and T2, the Ap-At (A. parkinsoniana-A. tepida) biofacies were characterized by species abundance, such as Ammonia parkinsoniana, A. tepida and Elphidium excavatum, associated with the composition of medium to coarse sand with disarticulated, broken and fragmented shells, suggesting advance sea level occasioned by storm wave and sea level variations, while the C-H (calcareous-hyaline) biofacies were characterized by few foraminifera and shells, suggesting retreat sea level and subsequent remobilization of marine sediments toward the shoreline. The core T3, collected at the Barra Franca channel differed from the two cores previous by presenting the species Poroeponides lateralis, Pseudononion papillatum and Nonion spp as the most representative, due to the beach influence, although in small quantities throughout the core, due activities of dredging and tidal sediment transport.