新疆喀拉通克铜镍矿区植物地球化学特征及找矿有效植物和元素的选择

摘要

喀拉通克铜镍矿区植被属土砾质荒漠植被类型。优势植物群落为白茎绢蒿（Seriphidium terrae-albae （Krasch.）Poljak），主要伴生植物有小蓬（Nanophyton erinaceum（Pall.）Bunge）、冷蒿（Artemisia frigida Willd.）等。通过对该区植物地球化学及植物对元素的积聚性研究，发现本区植物主要为富 Ca、Mg 贫 K、Na 地球化学类型。从区域背景→矿区背景→矿床上部，植物群落总体和多数植物种属的成矿及伴生元素含量逐渐增高；概率分布曲线从单峰正态分布到多峰分布；元素在不同植物种属中的分配不均匀。区域背景植物中的 Cu、Ni 含量与大多数元素呈正相关的关系；矿床上部 Cu、Ni 与其他元素正相关程度降低甚至出现负相关。植物对元素的吸收具有选择性和屏障效应。植物中积聚系数大的元素其衬度反而降低，积聚系数小的其衬度反而增高。本区白茎绢蒿、小蓬、冷蒿等植物可作为植物地球化学勘查的重要采样介质；驼绒藜、角果藜等可作为辅助采样介质。Cu、Ni、Ag 可作为优先选择的指示元素；Pb、As、Bi、Co、Au 可作为一般性指示元素；Zn、Cr、Mn、Mo 不宜作为指示元素。%The vegetation in Kalatongke Cu-Ni ore field belongs to a type of soil gravel hungriness one.Seriphi-dium terrae-albae(Krasch.)Poljak.is a dominant floral community and Nanophyton erinaceum(Pall.)Bunge and Artemisia frigida Willd.,etc.major associated plants in the ore field.The main geochemical type of plants in this region are rich in Ca and Mg,but poor in K and Na.From the region background area,the mining area to the upper part of the deposit,contents of ore-forming elements and associated elements increase gradually and probability distribution curve changes from single peak normal distribution to multi peak distribution in plant community and most plant species.Distribution of elements in different plant species is uneven.Contents of Cu and Ni in plants have positive correlation relationships with most elements in the background area,but their pos-itive correlation degree with other elements decreases and even appears negative correlation in the upper part of the deposit.Plant absorption of elements has selective and shielding effects.When the accumulation coefficient of elements is large,their contrast decreases,but the accumulation coefficient of elements is relatively small, their contrast increases in plants.In this ore field,Seriphidium terrae-albae(Krasch.)Poljak.,Nanophyton eri-naceum(Pall.)Bunge and Artemisia frigida Willd.,etc.can be used as important sampling media and Cera-toides latens (J.F.Gmel.)Reveal &N.H.Holmgren and Ceratocarpus arenarius L.,etc.can be used as auxilia-ry sampling medium in phytogeochemistry prospecting.Cu,Ni and Ag can be used as preferred indicator ele-ments,Pb,As,Bi,Co and Au can be used as general indicator elements and Zn,Cr,Mn and Mo should not be used as indicator elements.