CHARACTERIZATION OF THE WATER SEDIMENTARY CONDITIONS OF ITAPUÃ BEACH, SALVADOR-BAHIA, DURING THE 2014 RAINY SEASON

ABSTRACT

Bioclasts correspond to limestone skeletal remains of marine and/or freshwater organisms, which have a recognizable surface feature, and which therefore can be used in order to characterize the aquatic environment in terms of its hydrodynamics. Based on this aspect, this article aimed to characterize the hydro-sedimentary conditions of Itapuã beach, located in the city of Salvador - Bahia, using the biogenic/bioclast components of the sediment as descriptors. As for methodological aspects, 30 samples of surface sediments were collected, these points being distributed along the beaches of Farol de Itapuã, Rua K, Quiosque da Janaína and Sereia, 20 parallel to the beach face equidistant in 120m and 10 perpendicular with 50m of distance between the points, which were washed and dried in the laboratory and analyzed for their bioclastic composition, taphonomy, distribution, granulometry and calcimetry. As for the results, it was possible to group the bioclasts into 16 biogenic categories, with the calcareous algae category (>55%) being the most abundant. A heterogeneous distribution was found, with a predominance of autochthonous grains, mottled in color, with abrasion, with rounding level 3 and relics, indicating that the surface sediments are being reworked in the analyzed area. Low carbonate values (> 48%) indicate a greater siliciclastic contribution and the predominance of the fine sand fraction indicates low hydrodynamics.