Bottom Faciology and Sediment Transport in Santos Bay, Southeastern Brazil

• Published in: Journal of coastal research pp. 1737 - 1740
• Main Authors: Fukumoto, M. M., Mahiques, M. M., Tessler, M. G.
• Format: Journal Article
• Language: English
• Published: Coastal Education & Research Foundation (CERF) 01.12.2006
• Subjects: Calcium carbonates; Coasts; Geological facies; Grain size; Nitrogen; Sand; Sediment deposition; Sediment transport; Sediments; Silts
• ISSN: 0749-0208; 1551-5036

Sedimentary organic matter offers a wide variety of proxies which have been used for the determination of the origin, transport and fate of modern sediments. In this study a characterization of the sedimentation in Santos Bay, Southeastern Brazil, based on the application of bulk organic matter parameters, together with grain-size data is presented, so as to better define the sediment distribution and transport. The study area corresponds to the sector of the coast immediately adjacent to the Santos Channel which receives the discharge from the largest Brazilian harbour as well as from the estuarine system in which the most important industrial complex of the Brazilian coast is located. The only sedimentation model for the area was proposed in the 70's and now seems to be out of date due to a series of man made operations such as dredging and a submarine sewage outfall system, built in the 80's. Seventy-one surface samples were collected in February 2002 with a van Veen grab sampler. For the facies characterization a cluster analysis was undertaken using the following parameters: calcium carbonate, silt and clay content, mean grain size, sorting, organic carbon, total nitrogen, and sulphur content, C/N and C/S ratios and ¹³C and ¹⁵N values. Six sedimentary facies were identified, and three main deposition areas, characterized by larger amounts of mud and organic matter, are found in the bay: (1) the mouth of the Santos channel; (2) a region to the west of Manduba Point and (3) the mid-western part of the Bay.