Major, Minor and Trace Elements in Surficial Sediments from the Open Adriatic Sea: A Regional Geochemical Study

Abstract

The concentrations and distributions of major (Al, Ca, Fe, K, Mg), minor (Mn, P, Ti), and trace elements (Ag, As, Ba, Be, Co, Cr, Cu, Ag, La, Ni, Pb, Sc, Sr, Th, U, V, Zn, Zr), in the surficial sea bottom sediments were studied in an attempt to establish their distribution in the Adriatic Sea. Results indicate that major, minor and several trace elements are strongly related to the catchment geology, their distribution being essentially controlled by the type of sediments. However, the majority of trace elements are believed to have been introduced into the Adriatic from the riverine inflows that are also affected by the impact of industrial, mining and urban wastes. Other sources of these elements are located along the coast. The highest concentrations for several trace elements were thus recorded from the coastal ecosystems and from the most polluted Albanian and Italian rivers. The concentrations of trace elements generally decrease with distance from the coast. The regional distribution patterns are influenced by the counter-clockwise system of the Adriatic Sea currents which carry these elements away from the riverine inflows. Correlation analysis indicates that the trace elements are largely associated with the clay minerals, Fe and P contents rather than with the Mn concentrations. Magnesian minerals are suggested as the carrier for some trace elements (As, Co, Cr, Ni, Se and V) only in the southern Adriatic, which reflects their ophiolitic origin in the Albanian hinterland. Organic matter concentrations does not considerably influence the abundance and distribution of trace metals.