Características dos sedimentos do Arquipélago do Bailique com base em análises granulométricas

Abstract

The Bailique archipelago is part of the estuarine system at the mouth of the Amazon River. In the dry season, October 2017, 18 samples of sediment from the bottom of the channels were collected on the surface in six transversal profiles. Coarse sediments were washed, dried and sieved while fine sediments were pipetted. The data on the weight retained in each average diameter were entered into the Granulometric Analysis System (SYSGRAN) which provided grain size, selection, asymmetry and kurtosis. Analyzing the results obtained, it can be observed that the sediments that compose channels along the Bailique archipelago are predominantly of coarse silt size, poorly sorted, with asymmetric positive and leptokurtic curves. Sediments were classified by the Shepard diagram as sandy silt to silty sand. The Pejrup diagram, on the other hand, indicates a very high hydrodynamic environment, which is in agreement with an estuarine area strongly influenced by tidal action.