Geochemistry Of Major And Trace Elements In Bed Sediments Deposited At Xiangtan Section Of The Xiangjiang River

In this paper, the X-ray fluorescence(XRF) and inductively coupled plasma mass spectrometry(ICP-MS) analysis techniques,analysis of the major elements and heavy metals in sediments from Xiangjiang River of Xiangtan section. The results showed that: the major elements in the sediment core is relatively stable, the cv value of SiO2、Al2O3、Fe2O3、K2O、MgO、TiO2、Na2O belows 0.2. CN-A-K Plot indicates that sediment had gone througth a middle degree of chemical weathering,which results that Ca、Na elements have been run off. In addition, sediments also showed a trend of the distribution of the K-side along the AK line. Show that the the sediments existing K-feldspar preliminary weathering off potassium aluminum-rich.Enrichment index results indicate that: sediment is concentrated and enriched with element Mn、Zn、Pb, V、Cr、Cu、Th、U has reached to middle contamination.The rare earth element distribution plot the indicate that light rare earth element is relatively enriched and heavy element is relatively depeletion; the rare earth element distribution plots’ cuve slop is very big between La to Eu and significately tends to right side which may indicate that the light rare earth element fraction is very high; while the rare earth element distribution plots’ cuve slop is relatively smonth between Gd to Lu, which may also indicate the heavy rare earth element fraction is very low, Eu has significantly negative abnormal. Some stable element in the study area sediment core indicate that upstream granite, sedimentary rock is mainly the sediment source.Evaluation by using the geo-accumulation index(Igeo)shows that: Baelement is no pollution; Sc 、Cr 、Co、Ni 、 Th、U、 V has slight contamination, heavy element Mn、Pb、Zn is between patial middle contamination to middle contamination.Sediment mineral analysis indicate that quatz 、 clay mineral(illite 、 kaoline) 、 magnetite 、feldspar(orthoclass 、 calciclass 、 sodaclass) 、 ilmenite 、 zircon 、hypersthene、alpatite、rutile mica、olivine、amphibole、pyromusite、limestone are the main mineral in this study area. Xiangtan sediment’s heavy metal occurrence state analysis indicate that:Sc、Co、Ni、V、Co(slightly contamination) may be hosted in clay mineral、alpatite and may easily been release. Th、U may been hostd in ilmenite or rutile,which may recede the heavy metal’s mobility. Patially to middle contamination elements Cu、Pb、Zn have weak relation with almost major element,which may indicate human resource contamination and we should pay attention to them. Element Mn has middle contamination which may relate to its Mn mineral. Obove all, we should pay more attention to the contamination of Cu、Pb、Zn、Mn.