Sedimentary Patterns and Spatial Distributions of Heavy Minerals along the Continental Shelf in the Espírito Santo State, Brazil

Abstract

Heavy minerals can be used as tools to better understand sedimentary patterns across continental shelves, in addition to their economic importance, where they form marine placers. This study investigates the spatial distributions of heavy minerals in sand deposits along the three different morpho-sedimentary compartments (i.e., Paleovalley Shelf, Doce river Shelf, and Abrolhos Shelf) of the Espírito Santo Continental Shelf, which presents distinct sedimentary regimes. A mineralogical characterization of 180 surface sediment samples allowed to identify fifteen different heavy mineral species across the study area, with a predominance of ilmenite. The qualitative characterization shows similar heavy mineral patterns among the three compartments, while their mineral proportion (quantitative analysis) is heterogeneous. Also, the supply and accommodation regimes do not responsible by influence the heavy mineral assemblages and sediment maturity. However, there is a significant relationship between supply regime (delta sedimentation) and higher average abundances of each heavy mineral species. With results found here is possible to affirm that marine placers are closely related to Holocene sedimentation.