ANTARCTIC MARINE-SEDIMENTS - DISTRIBUTION OF ELEMENTS AND TEXTURAL CHARACTERS

The analysis of trace metals and their distribution in marine sediment s is a very important step toward understanding geochemical and enviro nmental processes and their possible changes due to anthropogenic acti vities. The present work reports results concerning the distribution o f some major (Al), (Fe), and trace (Be, Cd, Cr, Mn, Ni, Pb, Sn, Zn) el ements in Antarctic marine sediments. Chemical data were evaluated bef ore and after extraction with 0.5 N HCl, taking into account the textu ral character of the sediments. The mean values of total metals in the <2-mm granulometric fraction were (mg/kg) (Al) 56,100 +/- 3900; (Be) 2.04 +/- 0.25; (Cd) 0.26 +/- 0.16; (Cr) 20.3 +/- 8.3; (Fe) 16,400 +/- 4800; (Mn) 359 +/- 108; (Ni) 6.31 +/- 3.5; (Pb) 20.7 +/- 2.8; (Sn) 2.1 2 +/- 0.71; and (Zn) 42.3 +/- 10.4. With the exception of Be, all the elements showed higher concentrations in the fraction <63 mu m The eff iciency of extraction with 0.5 N HCl was generally low, as expected fo r unpolluted sediments. The relative percentage extraction of various elements was similar in the two fractions, with the exception of lead which presented a sensibly increased value in the fraction <63 mu m. T he results indicate that our samples are typical of areas not affected by anthropogenic inputs of elements and that potential polluting comp ounds are not bound within the structure of clay minerals. (C) 1998 Ac ademic Press.