云南省滇池—抚仙湖地区土壤地球化学背景及元素分布特征

The soil geochemical background and the elements distribution characteristics in Dianchi Lake—Fuxian Lake area,Yunnan province

滇池—抚仙湖地区表层土壤C、有机C、Cd、N、S、P含量明显高于深层土壤.第四系、岩溶区及盆地主要富集重金属元素,基性火山岩区富集铁族元素,昆阳群主要富集营养元素.湖泊沉积物以富集有机C、N、S、CaO、Na_2O及重金属元素为特征,其中滇池富集Hg、Pb、As、Cu、Zn,星云湖主要富集Pb、Hg、Cd,杞麓湖富集Cd、Cr,阳宗海富集Cd、As,抚仙湖富集CaO、S、Na_2O.浅水湖沉积物由下向上分为3层,灰色层1.5~2m深,富含有机质和碳酸钙;红色层0.2~1.5m之间,为高速沉积层,富集Al_2O_3、Fe_2O_3和P、Pb、Cu、Cr、Mn等;黑色层0~0.2m,湖积物为灰黑色有机质淤泥,富集有机C、CaO及重金属元素,是湖水富营养化的表现.

In Dianchi Lake—Fuxian Lake area,the contents of C,Org.C,Cd,N,S and P in surface soil were significantly higher than those in deep soil.Quaternary,Karst areas and basins are mainly enriched with heavy metal elements,the basic volcanic rock is enriched with iron group elements and the Kunyang group is mainly enriched with nutrient elements.The lake sediments are characterized by enrichment of Org.C,N,S,CaO,Na_2O and heavy metal elements.Among them,Dianchi Lake is enriched with Hg,Pb,As,Cu and Zn,Xingyun Lake is enriched with Pb,Hg and Cd,Qilu Lake is enriched with Cd,Cr,Yangzonghai Lake is enriched with Cd,As,and Fuxian Lake is enriched with CaO,S and Na_2O.The sediments of shallow lake are divided into three layers from the bottom to the top,the gray layer is 1.5—2 m deep,enriched with organic matter and calcium carbonate; the red layer is 0.2—1.5 m,which is high-speed sedimentary layer,enriched with Al_2O_3,TFe_2O_3 and P,Pb,Cu,Cr,Mn,etc.; the black layer is 0—0.2 m,which the lake sediments are gray-black organic matter sludge,enriched with Org.C,CaO and heavy metal elements,and is the performance of lake eutrophication.