engleski

Distribution of some less studied trace elements (Ga, Ge, Nb, Te, Tl, W) and some rare earth elements (La, Y) in sediment cores from unpolluted marine and freshwater lakes in Croatia

Distribution of some less studied trace elements (Ga, Ge, Nb, Te, Tl, W) and some rare earth elements (La, Y) in sediment cores from unpolluted marine and freshwater lakes in Croatia N. Mikac1*, N. Bačić1, M. Lučić1, I. Sondi2 1Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, Zagreb, Croatia 2Faculty of Mining, Geology and Petroleum Engineering, Pierottijeva 6, University of Zagreb, Zagreb, Croatia Vertical profiles of some less studied trace and rare elements (Ga, Ge, Nb, Te, Tl, W, La, Y), including also some of technology-critical elements, were studied in sediment cores taken in marine and freshwater lakes located within protected areas in Croatia. The marine lake (the Lake Mir) is a part of the Nature Park Telascica, and represents a small, shallow marine lake situated in the south-eastern part of the Dugi otok Island in a karstic landscape of the eastern Adriatic coast. The freshwater lakes (the Plitvice Lakes), a pristine hydrological system of sixteen karst lakes, are situated in a sparsely populated area of the northwestern Dinarides, central Croatia, and are included on the UNESCO World Natural and Cultural Heritage List. These lakes are not directly exposed to the anthropogenic influence, so it is interesting to study such environmental archives and evaluate the existence of possible temporal trends of concentrations of less studied trace elements. Undisturbed sediment cores, between 50 and 100 cm long, were collected using the Uwitec gravity corer and subdivided into 2 cm segments. After drying and homogenization samples were digested in a microwave oven by a two-step total digestion procedure and the trace elements were analyzed by High Resolution Inductively Coupled Plasma Mass Spectrometry (HR ICPMS). Quality control of the used analytical method was verified by the analysis of available geological certified reference materials (CRM) certified for the content of less studied trace elements. In the paper vertical profiles and geochemical behavior of less studied elements will be discussed in comparison with chosen major and trace elements which can serve as indicators of terrigenic and anthropogenic influences and sedimentation processes.

TCE ; marine and freshwater lakes ; sediment

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