5 documents found, page 1 of 1
Hydrodynamic controls on the distribution of surface sediments from the southea...
Nagai, R. H.; Ferreira, P. A. L.; Mulkherjee, S.; Martins, M. V.; Figueira, R. C. L.; Sousa, S. H. M.; Mahiques, M. M.This study aims to explore the hydrodynamic factors that influence the depositional processes on the upper continental margin of southeastern South America. Mineralogy and the activities of natural (40K) and artificial (137Cs) radionuclides from surface sediment samples were used to evaluate the provenance and oceanographic controls on depositional processes. High values of the smectite/illite (S/I) ratio indic...
Distribution of living planktonic foraminifera in relation to oceanic processes...
Sousa, S. H. M.; de Godoi, S. S.; Amaral, P. G. C.; Vicente, T. M.; Martins, M. V. A.; Sorano, M. R. G. S.; Gaeta, S. A.; Passos, R. F.; Mahiques, M. M.The vertical distribution (0 to 100m) of planktonic foraminifera was investigated based on 40 tow samples that were collected in eight stations, during the austral summer of 2002, in a geographically restricted area (23°S-25°S and 40°W-44°W) on the southeastern Brazilian continental margin. Species' abundances are low (less than 10 specimens/m3), which is typical of an oligotrophic area. The foraminifera assemb...
Records of sedimentary dynamics in the continental shelf and upper slope betwee...
Martins, V.; Abrantes, I.; Grangeia, C.; Martins, P.; Nagai, R.; Sousa, S. H. M.; Laut, L. L. M.; Dias, J. M. A.; Dias, J. M.; Silva, E. F. daThe sedimentary unconsolidated cover of the Aveiro–Espinho continental shelf and upper slope (NW Portugal) records a complex interplay of processes including wave energy and currents, fluvial input, sediment transport alongshore and cross-shelf, geological and oceanographic processes and sediment sources and sinks. In order to study this record, a set of surface sediment samples was studied. Sediment grain size...
The response of benthic foraminifera to pollution and environmental stress in R...
Martins, V.; Yamashita, C.; Sousa, S. H. M.; Martins, P.; Laut, L. L. M.; Figueira, R. C. L.; Mahiques, M. M.; Silva, E. F. da; Dias, J. M. A.This work evaluates the quality of the sediment in Ria de Aveiro, a coastal lagoon located at N of Portugal that is under strong anthropic influence, and the effects of the contamination on benthic foraminifera. The initial approach for measuring pollution was done through the load pollution index (LPI), based on As, Cd, Cr, Cu, Ni, Pb and Zn concentrations, and determined by total digestion of the sediments (T...
The response of benthic foraminifera to pollution and environmental stress in R...
Martins, V.; Yamashita, C.; Sousa, S. H. M.; Martins, P.; Laut, L. L. M.; Figueira, R. C. L.; Mahiques, M. M.; Ferreira da Silva, E.This work evaluates the quality of the sediment in Ria de Aveiro, a coastal lagoon located at N of Portugal that is under strong anthropic influence, and the effects of the contamination on benthic foraminifera. The initial approach for measuring pollution was done through the load pollution index (LPI), based on As, Cd, Cr, Cu, Ni, Pb and Zn concentrations, and determined by total digestion of the sediments (T...