柴达木盆地西部七个泉地区新近系狮子沟组沉积环境分析OA

[Objective]The sedimentary environment of ore-bearing layer is crucial to the formation of sandstone-type uranium deposits.The paleoclimate,palesalinity and paleo-redox conditions of the formation of Shizigou Formation are discussed,and the constraints on uranium mineralization are discussed from the aspects of salinity,humidity and REDOX conditions during the sedimentary period.[Methods]Based on the geochemical analysis of 12 sandstone samples of Shizigou Formation in Qiquan area of western Qaidam,the sedimentary environment of Shizigou Formation is studied by using the geochemical indexes sensitive to the sedimentary environment.[Results]The results show that the Sr/Cu value range is mainly from 6.80 to 65.08(in average of 18.71),K2O/Al2O3 value range is from 0.16 to 0.21,Sr/Ba value range is mainly from 0.31 to 0.93(in average of 0.56),U/Th value range is from 0.22 to 0.31,V/(V+Ni)value range is from 0.71 to 0.76,V/Cr value range is from 1.23 to 1.43,Ni/Co value range is from 1.51 to 2.67,Fe2+/Fe3+value range is mainly from 0.21 to 0.89(in average of 0.50),Cu/Zn value range is from 0.30 to 0.47,and δCe value range is from 0.84 to 0.97.[Conclusions]The geochemical data shows that the Shizigou Formation in the Qigequan area was formed in an oxygen-rich terrestrial freshwater lake environment and a cold,arid climate.