湘西北下寒武统黑色岩系钒镍钼矿微量元素地球化学

湘西北下寒武统黑色岩系是中国南方下寒武统黑色岩系的重要组成部分，富含钒镍钼等多金属元素。文中对湘西北下寒武统黑色岩系钒镍钼矿进行了微量元素研究，研究区内Ni、Cd、Mo、Sb、V、Zn、W、Ba等元素特别富集，高含量的Sb和Ba表明其为热水沉积；Mo含量极高说明其为缺氧的还原环境；高的V/（V+Ni）、V/Cr、Ni/Co以及δU值表明其沉积环境为缺氧环境；高的 U/Th表明本区有热水沉积作用；稀土元素配分模式、Ce和Eu异常及La/Yb Ce/La和La/Yb ΣREE图解投点表明其沉积环境为还原环境，并有热水沉积作用。可见黑色岩系形成于缺氧环境，热液活动为其提供了丰富的热液来源。

Trace element geochemistry of V-Ni-Mo deposits from the Lower Cambrian black rock series of Northwestern Hunan

The lower Cambrian black rock series in northwestern Hunan,rich in V-Ni-Mo polymetal elements,are an important part of lower Cambrian black rock series in South China.The present paper is aimed at the study of trace elements in this rock series.In the studied area some elements,including Ni,Cd,Mo,Sb,V,Zn,W,Ba,are heavily enriched.The high content of Sb and Ba and high U/Th in the black rock series reflects hydrothermal sedimentary environment.The high content of Mo and high V/(V+Ni),V/Cr,Ni/Co and δU indicate an anoxic sedimentary environment for these rocks.The REE patterns,Ce and Eu anomalies,La/Yb-Ce/La and La/Yb-ΣREE diagrams suggest that V-Ni-Mo deposit was formed in an anoxic sedimentary environment together with hydrothermal sedimentary processes.All the trace element geochemical characteristics of the black rock series indicate that the V-Ni-Mo deposit from Lower Cambrian black rock series in Northwestern Hunan was deposited in an anoxic sea environment.The seafloor hydrothermal activity provides the source for the abundant metallic elements.