보성강 표층퇴적물의 퇴적환경과 지화학적 특성 = Sedimentary Environment and Geochemical Characteristics of Surface Sediments in Boseong River

다국어 초록 (Multilingual Abstract)

Mean grain sizes of -1.06 ~ 2.26Ø in the surface sediments of Boseong River are assigned to granule to fine sand in size. The sediments are moderately sorted to poorly sorted, showing ranges of 0.62 ~ 1.45Ø (0.90Ø in mean). They are coarse to fine skewed and meso- to leptokurtic with ranges of 0.62 ~ 1.45Ø (0.90Ø in mean) and 0.93 ~ 1.30 (1.08 in mean), respectively. However, the skewness values of the sediments are irregularly changed. The sediments are classified into the four facies of sandy gravel (sG), gravelly sand (gS), slightly gravelly mud ((g)S) and sand(S), dominated in coarse sediments.
Mean contents of major, minor and heavy metallic elements in the sediments are low relative to that in the earth crust. Of above elements in the sediments, Al is highly correlated with Fe, Mg, Ti, P, Mn, Co, Cr, Ni, Sc, V, Cu, Zn, Pb, and Ca correlated with Sr. In addition, K is highly correlated with Mn and Pb. Exceptionally, Zr is lowly or negatively correlated with above all elements.
The elements are mainly controlled by two factors having the explanation of 76.04% to total variance. Factor 1 is highly loaded in Al, Fe, Mg, Ti, P, Mn, Co, Cr, Li, Ni, Sc, V, Cu, Zn, Pb and mean grain size. Therefore, it is closely interrelated with clastic sediments. Meanwhile, factor 2 is highly loaded in Ca, Ba, and Sr. It could be explained by rocks distributed around the study area on the bases of the similar ionic radii of Ca, Sr, Ba and their richness in plagioclases.
Elements of the sediments show following results; Fe, K, Ba, Li, Zr, Pb are enriched above 1 in EF, and Cr, Ni, Cu are above 1 in geoaccumulation index(Igeo), respectively. High enrichments of Fe, K, Ba, Li, Zr, Pb might be related with acidic rocks around the study area. Although Igeo values of Cr, Ni, Cu are above 1 in the area, it is considered that they are relatively no longer concentrated.