Caracterização dos depósitos sedimentares Holocênicos no sistema de ilhas barreiras do estuário Diogo Lopes, litoral setentrional do Rio Grande do Norte

Abstract

This article was developed in holocenic sedimentary deposits of a barrier island and sand spits system, typical of Diogo Lopes estuary, northern coast of Rio Grande do Norte. This environment is highly susceptible to erosional/depositional processes and strongly affected by wind regime, hydrodynamic and possibly by reactivation of early structures. This study used vibrocorer drilling technic associated with previous drill-cores and lithological sections, in addition to the correlation with regional geological features. This allowed to recognize four distinct sedimentary facies: Siliciclastic Sand with Granules and Gravels, Siliciclastic Sand, Terrigenous Mud and Sandy Marl. The analysis and interpretation of vibrocores endorsed to identify muddy facies (describing Intertidal Flat subfacies) and sandy facies (describing Tidal Inlet subfacies) interbeds, that highlight the intense coastal dynamic which the region is subjected, suggesting that the opening and closing of tidal channels occur in short time interval (range of years) and preferably in situations prior geological structural discontinuity