Sedimentological Sectorization of An Estuarine System In A Regressive Coast, Southeast Brazil

Abstract

Abstract Multivariate statistical analysis can be applied in order to group sediments with similar characteristics and be an important tool for the interpretation of sedimentary facies for a given depositional environment. This study investigates the use of multivariate analysis to produce a sectorization of an estuarine system located along a regressive coast (Espirito Santo, southeast Brazil). Results of cluster analysis and principal component analysis were compared to qualitative sediment interpretation based on well-known sediment classifications. Multivariate analysis defined four distinct sedimentary groups for the estuarine and adjacent inner shelf system. These groups reflect distinct sedimentary facies found along the system: inner estuarine facies, outer estuarine facies, fluvial–coastal facies, and shelf facies. This sectorization is used to propose a sedimentary facies model for the system. Sedimentological variables used in the sectorization were shown to be good indicators of depositional environments, indirectly expressing the hydrodynamic energy.