Mineralogy and Geochemistry of Marine Sediments in the Northeastern Gulf of Mexico

Abstract

In this study, five sediment cores (N57, N59, N60, N61, and N63) were recovered from the deep-sea area of the northeastern Gulf of Mexico (~1851 m, ~3057 m, ~3542 m, ~3726 m, and ~3738 m water depth, respectively). The grain size, mineralogy, geochemistry, and radiocarbon ages of the sediment cores were analyzed. N57 and N59 cores were characterized by detrital components enriched in SiO2, Al2O3, and Fe2O3 contents. On the other hand, the N60, N61, and N63 cores were abundant with planktonic foraminifer and depleted in detrital components. The weathering indices like Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA) revealed a low intensity of weathering in the source area. The enrichment Factor (EF), Pollution Load Index (PLI), and Geo-accumulation Index (Igeo) indicated that the sediments were moderately contaminated. 14C ages of foraminifer species indicated a maximum age of 1683 ± 52 calibrated years B.P.