The Sedimentary Characteristics and V Enrichment Mechanism of the Cambrian Terreneuvian Black Shale in the Eastern Guizhou
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.SiO2/Al2O3 ratios,Eu/Eu*values,plot of w(SiO2)-w(K2O+Na2O),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.
V polymetallicblack shaleenrichment lawCambrian TerreneuvianEastern Guizhou
万方数据
维普
