Geochemical variability of copper and iron in Oman margin sediments

Abstract

An analysis of the geochemical distribution of selected trace metals among various geochemical phases of the sediments in the Oman Margin was carried out using a sequential extraction technique. The present study showed that most Cu in abyssal sediment is associated with only oxidisable mainly organic and sulphide bound metals with insignificant bound to exchangeable, carbonates, easily/moderately reducible fraction. The preservation of Cu in the sediments indicates the importance of primary production and upwelling in the overlying waters and an organic flux in the sedimentary deposition of open-ocean environments. The early diagenetically formed oxidisable mainly organic and sulphide fraction are not degraded and results in a pronounced association of Cu with organic fraction in the sediments of the Oman continental margin. The strong correlation between Cu, TOC and Fe oxides associated with the oxidisable fraction in one of the core indicates that it is likely to be the presence of sulphides.