Geochemical study of sediments from the Amvrakikos Gulf logoon complex, Greece

Abstract

1 - Grain-size parameters, organic carbon, major and minor elements were determined in a suite of 50 surface sediment samples obtained from the Amvrakikos Gulf lagoons Rodia, Tsoukalio Logarou, and Tsopeli 2 - The shallow lagoon-floor (max. 3.1 m) was covered mainly by muddy sediments 3 - Most major and minor elements were found to be related with terrigenous aluminosilicates. Higher contents of S, Mo, Pb, organic C, and As were observed in Rodia lagoon, indicating temporary anoxic conditions. High Cr and Zr contents exhibited similar behavior with Si and were attributed to the presence of minerals chromite, zircon and quartz. Typical occurrences of biogenic elements (Ca, Sr) were also recorded. Relatively high heavy metal contents for V, Cr, Ni, and Zn were attributed to the natural weathering of metal-bearing ultra-basic rocks. 4 - The lagoon system is supplied by terrigenous material originating in the Rivers Arachthos and Louros and also directly by the weathering of rock formations. Due to the anticlockwise water circulation prevailing in Amvrakikos Gulf, particle-rich riverine waters from Arachthos entrain Logarou, whilst Tsoukalio and Tsopeli are mostly influenced by the neighboring Louros R.