松辽盆地南部保康地区钻孔铀矿化地球化学特征及意义OACSTPCD

Songliao Basin is one of the Middle Cenozoic continental sedimentary basins in China,this paper focuses on the study of the lower member Yaojia Formation in Baokang area of Songliao Basin as the primary target layer.Geochemical and spectroscopic analyses were conducted to investigate the characteristics of major elements,trace elements,sulfur isotopes,and organic matter in the host sandstones so as to explore the uranium mineralization characteristics and ore-forming prospects in Baokang area.The analysis results show that the samples from mineralized section in Baokang area are depleted in Si and enriched in Fe,Mn,especially S and TOC.Trace elements associated with uranium are Co,Ni,Mo,Cd,Re,Tl,Zr,while Mo,Cd,and Re are more intensely enriched and show significant correlation with uranium.The δ34S values of the mineralized samples from the lower member Yaojia Formation in Baokang area range from-17.7‰ to-2.7‰,lower than those of sterile samples,indicating that the main source of sulfur in pyrite is from the thermal decomposition of organic matter.Spectroscopic characteristics suggest that the organic matter in the samples has a relatively high maturity and shares some similarities with humic acid,suggesting its evolution from deep hydrocarbon source rocks.Combining the uranium ore characteristics in geochemistry and organic matter,it was concluded that uranium mineralization in Baokang area conformed to the features of leaching sandstone-type uranium mineralization.