Elemental and mineralogical characterization of marine sediments and their relationship to sedimentary and oceanographic processes in Central Bransfield Basin

Abstract

This work consists of the sedimentological, mineralogical, and geochemical characterization of eight marine sediment cores collected in the Central Bransfield Basin, along a transect between the South Shetland Islands to the Antarctic Peninsula and its correlation to the sedimentary and oceanographic processes of the area. A chemical characterization based on X-ray fluorescence dispersive spectrometry was implemented to obtain geochemical data of the marine sediment while the minerals were identified by X-ray diffraction. The study allowed to classify the cores into three groups according to their sediment source and chemical and mineralogical characteristics. The joint assessment of the geochemical and mineralogical signature of the sediment has confirmed that the elemental ratios Ti/Ca and Fe/Ca can be applied as proxies in the reconstitution of the terrigenous contribution to the Central Bransfield Basin if we consider the sedimentary contribution of the volcanic edifices present in the region. The Fe/K ratio associated with the Chemical Index of Alteration reinforced an increase in the degree of weathering near South Shetland Island, which is also pointed out by other authors in studies on climate change mainly in the subantarctic islands. The trend of temperature increase implies the importance of monitoring the region.

Key words
Antarctic; geochemistry; mineralogy; Sediments; oceanographic processes