Controls of Tellurium enrichment in the rare earth elements and yttrium (REY) rich deep-sea sediments from the Central Indian Ocean Basin (CIOB)

As a potential Te reservoir for the global budget, the occurrence, material sources, migration and enrichment mechanism of Te in deep-sea sediments remain unclear. Based on the major and trace elements measurements of bulk sediments, this study proposed a procedure to quantify the contribution of Te by main host minerals, combining with TIMA and LA-ICP-MS in two cores (GC04 and GC11) from the Central Indian Ocean Basin (CIOB) and a core from east of the 90 degrees E Ridge (GC03). Te shows the highest enrichment coefficient of 650 referred to UCC (Upper Continental Crust) in the REY (Rare Earth Elements and Yittrium) rich sediments in GC04, GC11 and GC02 (a core at the south of GC04 and GC11). Clinoptilolite-K and osumilite are indicated as the main host minerals, which correlates Te sources with volcanogenic materials and weathering products of terrigenous rocks. The inter elements correlation, cluster analysis and factors analysis further indicate distinct hydrothermal genetic Te. So, we put forward a hypothesis that Te is mainly sourced from the submarine volcanogenic hydrothermal activities, which are closely associated with local intraplate volcanism episodes from late Miocene with spatial and temporal differences. This study is the first attempt to quantify Te from different minerals and to reveal its geochemical behavior in the deep sea sediments, which will be benefit to the understanding of Te reservoir and cycle in deep sea and the comprehensive utilization of REY-rich deep-sea sediments. However, for the abundant presence of undetectable nanoscale minerals in these sediments, the contribution of Fe-Mn (oxyhydr) oxides and clay minerals of Te need more investigation.