Geochemistry and provenance of the sediment from the west flank of the spreading southwest Indian Oceanic Ridge (34.9°S)

The multi-origin sediments on the southwest Indian Ridge (SWIR) are the archive of environmental evolution of the region. The study of sediment characteristics and provenances founded the basis of paleoceanographic study. In this paper, we analyzed the deep-sea sediment samples from a gravity core sampled at 34.9°S on the spreading SWIR, and a comprehensive data set was constructed for their bulk chemical compositions, including major elements, trace elements, and bio-components. As the data show, the bulk samples are dominated by bio-components, consisting of high bio-carbonate and low bio-silica. The distribution patterns of major elements are rather accordant. Except for Ca, Sr, and LOI, the correlation coefficient of other major elements are greater than 0.8. Based on the properties of bio-components of sediment, we computed the weight percentage of each bio-component. Removed the bio-components from the bulk, we recalculated the weight percentage of non-biotic elements. The data is used as geochemical proxies to study the potential sources. It is found that the abiotic component of the sediment is mainly terrestrial and local origin. The primary source is the aeolian dust from southern Africa, with a small amount of deposits from hydrothermal sulfide and manganese crust.