内蒙阿拉善脑木洪铜矿区的植物地球化学特征

CHARACTERISTICS OF PHYTOGEOCHEMISTRY IN NAOMU-HONG COPPER MINE AREA AT THE ALASAN OF NEI MONGGOL

在脑木洪铜矿区,13种植物或植物部分的灰分中,9种元素含量水平为锰>铜>锌>铬>镍>铅>钴>镉>银;种间元素含量差别最大的为铜,最高和最低相差20多倍。绵刺(Potaninia mongolica)铜含量最高,平均为735.2ppm,在不同地点的铜含量变化范围为209—1543ppm;珍珠(Salsola passerina)铜含量最低,平均为31.01ppm,变化范围为18—54ppm。同种植物在不同岩性上的铜、锌含量,矽卡岩>花岗岩、灰岩>砂岩。植物中金属元素含量之间均呈正相关关系。镉和银分别与其它8种元素之间未达显著相关水平,铜、铬等6种元素之间分别达显著或比较显著相关水平。土壤和植物中元素之间相关分析结果,均呈正相关关系;绵刺的锌.铅,霸王(Zygophyllum xanthoxylum)的铅,琵琶柴(Reaumuria soongorica)的铜等,达显著和比较显著相关。绵刺、琵琶柴铜地球化学异常,与矿体密切相关,异常区不仅包括了露头矿,而且包括了盲矿体的分布范围。

Characteristics of element contents(in ash) for 13 plant species in Naomuhong Cu mine area are disscussed.Results show that the level of element contents in sequence is:Mn>Cu> Zn>Cr>Ni>Pb>Co>Cd>Ag.Cu contents exhibit the greatest difference between species,with a 20 fold difference or more between maximum and minimum contents.Cu content is maximal in Potaninia mongolica,being from 209 ppm to 1543 ppm at various sites,with a mean of 735.2 ppm;whereas Cu content is minimal in Salsola passerina,being from 18 ppm to 54 ppm at various sites,with a mean of 31.01 ppm.Cu,Zn contents in skarn are more than in granite and those in limestone are mote than in sandstone.Correlation coefficients of linear regression between elements in the plants are of positive values.However,they are not significant between Cd,Ag and other eight elements,and between Cu,Cr et al.six elements are significant respectively.The correlative coefficients between elements in plants and soils are positive,Zn and Pb contents between P.mongolica and soils,and Pb content between Zygophyllum xanthoxylum and soils,and Cu content between Reaumuria soongorica and soils and significant. It is found that Cu phytogeochemical anomalies in P.mongolica and Reaumuria soongorica correlate closely with Cu ore deposit,and the anomalies were found not only in the outcropping ore,but also in the blind ore deposits.