贵州早寒武世的缺氧事件沉积  

Early cambrian anoxic event sedimentation in Guizhou province

作　　者：肖加飞[1] 胡瑞忠[1] 宋谢炎[1] 陈兰[2] 

机构地区：[1]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵阳550002 [2]重庆科技学院石油工程学院,重庆400042

出　　处：《矿产与地质》2006年第4期366-373,共8页Mineral Resources and Geology

基　　金：中国科学院知识创新工程重要方向资助项目(KZCX3-SW-125);国家自然科学基金项目(40573014)资助

摘　　要：贵州早寒武世的黑色岩系属中国南方该时期缺氧事件沉积的一部分，为一套沉积速率低的海侵体系城沉积．主要为黑色页岩，发育水平纹理，主要含浮游生物，其中产钼、钒等矿床。其具有独特的元素地球化学特征：SiO2、TiO2、Al2O3的含量相对较高；富集Mo、V、Ba、Ag、Au、U等元素，而Co、Sr、Ta等元素却亏损；稀土总量不高，为130×10^-6～226×10^-6，稀土配分曲线形态近于水平或略向右倾，具弱的负Ce异常和正Eu异常．地层特征、元素地球化学特征及特征元素比值所反映的是早寒武世黑色岩系形成于缺氧的还原环境，而缺氧沉积中有热水沉积的加入。The Early Cambrian black rock series in Guizhou Province are a part of Early Cambrican anoxic event sedimentations in South China. This sediment series belong to transgressive system deposition showing lower rate of sedimentation. The black rock series mainly consist of black shale, having horizontal lamination, containing mostly Plankton, forming Mo.V ore deposit etc. The black rock series have some distinctive characteristics in elemental geochemistry： There are relatively higher SiO2, TiO2 and Al2O3 content： Mo,V,Ba,Ag,Au,U,etc are relatively abundant, but Co,Sr,Ta,etc are deficient; The total REE content changes from 130 to 226 ppm, The REE patterns of the investigated samples normalized by North American Shale show almost flat or slight inclination rightward, There are slight negative Ce anomalies and positive Eu anomalies. The characters of stratum and elemental geochemistry, characteristic elements and their ratios indicate that Early Cambrian black rock series were formed in anoxic reductive circumstance, and the hydrothermal sediments were joined into the anoxic deposition.

关 键 词：早寒武世 缺氧事件 黑色岩系 热水沉积 贵州 

分 类 号：P534.41[天文地球—古生物学与地层学]