engleski

Impact of karst bauxite mining on the geochemistry of topsoil and stream sediments in Dalmatia, Croatia

The Croatian carbonate terrains, consist of karstic Dinarides, the Adriatic belt and the Adriatic Island which have the attributes of carbonate platforms cover approximately 50% of Croatian territory. Within the karst of the Dalmatian region more than 2000 deposits of bauxite were located within a belt 150 km long and were mined during the second half of the 20th century. The bauxites are enriched Cr, V, As, Cd, Ni and Pb. The results of a geochemical topsoil mapping program which covered the whole Croatian karst region with almost 1700 sampling sites showed that the soils from the Dalmatian region had 30 to 50 % higher concentrations of these metals than other karst regions. During this study using normalization on conservative elements, sequential leaching experiments (BCR-protocol), mineralogical and GIS methods an attempt was made to determine weather the elevated concentrations of metals in soils are a consequence of bauxite mining or is the bauxite signature in the soils inherited as a geogene imprint of bauxite dust debris from outcrops on soil formation during the Pleistocene and Holocene as well as the overall influence the amounts of available metals within Adriatic catchments and their influence on water quality.

Heavy metals; Bauxite; Dalmatia

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