贵州遵义黄家湾下寒武统牛蹄塘组镍-钼富集层电子探针研究

对贵州遵义黄家湾下寒武统牛蹄塘组镍-钼富集层进行电子探针研究,发现镍主要赋存于黄铁矿、针镍矿、辉砷镍矿、铁辉砷镍矿、紫硫镍矿、赫硫镍矿;钼主要以"碳硫钼矿"的形式存在。镍钼硫化物多与黄铁矿、白铁矿交代共生,反映矿物经历了不同的成矿阶段。岩石中不仅富集Ni、Mo元素,而且Se元素存在超常富集,可以视为热液作用或生物作用的结果。遵义黄家湾下寒武统Ni-Mo富集层应为海底热液沉积和生物沉积混合成因,其物源较为复杂。

EMPA RESEARCH ON NICKEL AND MOLYBDENUM MINERALS IN Ni-Mo SULFIDE LAYER OF THE LOWER CAMBRIAN BLACK ROCK SERIES AT HUANGJIAWAN, ZUNYI, GUIZHOU PROVINCE

In this study,several minerals such as pyrite,vaesite,gersdorffite,Fe-bearing gersdorffite,violarite and heazlewoodite;and a C-Mo-smixed-layer phase(MoSC) have been detected from the Ni-Mo ores at Huangjiawan,.Zunyi,Guizhou Province,on the basis of electron microprobe analyses.Ni occurs mainly in Ni-minerals mentioned above.Mo occurs as MoSC.Se is distributed almost in the whole Ni-Mo sulfide layer with higher contents in the Ni-Mo-rich strata of the Lower Cambrian Niutitang Formation.The present study indicates that the origin of Ni-Mo sulfide layer is related to sea-floor hydrothermal exhalation and biological accumulation.