黔东地区寒武系纽芬兰统黑色岩系沉积特征及V多金属的富集机制  

The Sedimentary Characteristics and V Enrichment Mechanism of the Cambrian Terreneuvian Black Shale in the Eastern Guizhou

作　　者：谯文浪 杨瑞东[1] 付勇[1] 倪莘然 陈武 季国松 马义波 QIAO Wenlang;YANG Ruidong;FU Yong;NI Xinran;CHEN Wu;JI Guosong;MA Yibo(College of Resources and Environmental Engineering,Guizhou University,Guiyang Guizhou 550025,China;102 Geological Party,Guizhou Bureau of Geology&Mineral Exploration,Zunyi Guizhou 563000,China;Guizhou Geological Survey,Guiyang Guizhou 550081,China)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]贵州省地矿局一〇二地质大队,贵州遵义563000 [3]贵州省地质调查院,贵州贵阳550081

出　　处：《矿物学报》2024年第6期763-781,共19页Acta Mineralogica Sinica

基　　金：贵州省地质矿产勘查开发局地质科研项目(编号:黔地矿科合[2022]5号);中国地质调查研究项目(编号:KD-[2020]-XZ-036);国家重点研发计划(编号:2022YFF0800204);国家自然科学基金资助项目(编号:U1812402)。

摘　　要：早寒武世贵州普遍沉积了一套黑色页岩,但其沉积相存在明显差异。凯里−三都地区总体为盆地相至斜坡相的寒武系纽芬兰统黑色岩系是区内V多金属元素的重要产出层位。本文选取贵州凯里−三都地区寒武系纽芬兰统典型黑色页岩剖面,对含V岩系展布规律和沉积特征进行综合调查研究。分析测试V及其相关元素的含量以揭示V元素的空间分布规律及其地球化学特征。结果表明,V从北往南富集程度呈降低趋势,垂向从下往上呈降低趋势。Al/(Al+Fe+Mn)值、Y/Ho值及Sm/Nd-Eu/Sm值等地球化学特征,指示该区沉积时的物源是以陆源为主;SiO_(2)/Al_(2)O_(3)、Eu/Eu^(*)值、w(SiO_(2))-w(K_(2)O+Na_(2)O)以及不同沉积物中Fe、Mn和微量元素Ni、Co含量等,指示研究区内存在热水沉积作用;Mo、Ba、U等元素富集系数均值,Co、Sr、Ce异常特征,Th/U、Ni/Co和V/Cr值等指示研究区内含V岩石沉积环境趋向于缺氧(还原)环境-弱氧化环境,寒武纪区域古地理演化影响了黑色页岩中V的富集。Black shales are widely deposited in Guizhou Province during the Early Cambrian period,however,their sedimentary facies are significantly different.The typical layer of Cambrian Terreneuvian black shale series of generally basin facies to slope facies in the Kaili-Sandu area,Guizhou Province is an important layer of V-polymetallic hosted rocks in the area.In this paper,a typical section of Cambrian Terreneuvian black shale series in the Kaili-Sandu area of Guizhou Province was selected for undertaking a comprehensive investigation of the distribution regulation and sedimentary characteristics of the V-bearing rock series.The contents of V and its related elements of samples were analyzed to reveal the spatial distribution regulation and geochemical characteristics of vanadium.The results show that the V concentrations are decreased for samples collected from north to south of the horizontal section,and from bottom to top of the vertical profile.Geochemical characteristics including Al/(Al+Fe+Mn)ratios,Y/Ho ratios,Sm/Nd and Eu/Sm ratios indicate that the black shale series was mainly sourced from terrigenous materials during the sedimentation.SiO_(2)/Al_(2)O_(3)ratios,Eu/Eu^(*)values,plot of w(SiO_(2))-w(K_(2)O+Na_(2)O),and contents of Fe,Mn,and trace elements(e.g.,Ni and Co)for different black shale samples indicate that there was the hydrothermal sedimentation in the study area.The mean values of enrichment coefficients of Mo,Ba,and U,and abnormal characteristics of Co,Sr,and Ce,Th/U ratios,Ni/Co ratios,and V/Cr ratios of samples indicate that the sedimentation environment of the V-bearing rock in the study area was anoxic(reduced)environment or weakly oxidizing environment.The Cambrian paleogeography evolution had affected the V enrichment in the black shale.

关 键 词：V多金属 黑色岩系 富集规律 寒武系纽芬兰统 黔东 

分 类 号：P571[天文地球—矿物学] P536[天文地球—地质学]