中文摘要：

湖南张家界三岔和贵州遵义黄家湾在下寒武统黑色岩系中发育有镍钼多金属矿床,这是华南乃至全球这类矿床的2个典型实例。通过对其进行系统的矿相显微镜、电子探针以及扫描电子显微镜观测分析,分析了成矿岩系的矿物学特征,并进一步根据矿物结构、组成与共生关系,结合地质背景,讨论了矿床成因。结果显示,非矿层中的金属矿物类型较为单一,主要是黄铁矿;而矿层中发现的矿物种类丰富,主要包括＂碳硫钼矿＂、针镍矿、黄铁矿、胶磷矿等,其中＂碳硫钼矿＂和针镍矿分别是钼与镍的主要赋存形式。认为钼主要来自于海水,镍主要来自于热水（液）流体,矿床为海水-热水（液）-生物复合成因。这些研究结果为此类矿床研究提供了新的矿物学基础研究资料,并且有助于加深对矿床成因的认识。

英文摘要：

The Ni-Mo polymetallic deposits hosted in Early Cambrian black rock series in the Zhangjiajie Sancha of Hunan Province and Zunyi Huangjiawan of Guizhou Province,China are the two representative cases of such deposits in southern China and even worldwide.Mineralogical features of the two deposits were revealed by relatively comprehensive analyses including mineral microscopic observation,electron microprobe analyses and scanning electron microscope observation.The origin of the deposits was further addressed mainly based on the structure,composition and mineral intergrowing relationship.Analytical results show that pyrite is the primary mineral phase in the non-mineralized black shales.In contrast,a variety of minerals present in ore beds,including C-Mo-S mixed-layer phase（MoSC）,millerite,pyrite and cellophane.Mineral elements Mo and Ni primarily presented in C-Mo-S and millerite and sourced from sea water and hydrothermal fluid,respectively.The origin of the deposits is influenced by mixing effects of seawater,hydrothermal fluid and bio-organic matter.These results not only provide new mineralogical information for the study on the deposits,but also are helpful for improving the understanding on the origin of the deposits.