新疆乌恰县萨热克铜矿区古盐度恢复及与成矿关系

The Palaeosalinity Analysis and Metallogenic Relationship of Sareke Copper Deposit

通过对萨热克巴依次级盆地萨热克砂砾岩型铜多金属矿区泥岩样品中微量元素硼、锶、钡及K2O含量测试.在古盐度计算中结合Walker相当硼判定法、Walker计算公式及锶钡比值法对其进行定量—半定量地分析,得出矿区古盐度特征.研究统计古盐度值介于0.37%~3.16%,沉积环境以半咸水为主,淡水—微咸水沉积次之,个别样品为咸水沉积;古盐度变化明显,其中古盐度值最高的是中侏罗统塔尔尕组(J_2t),其次是上侏罗统库孜贡苏组(J_3K),古盐度最低的是下白垩统克孜勒苏群(K_1kz^(2-1)).沉积环境的判别标志之一取决于沉积物中泥岩沉积时的古盐度特征,因此古盐度的恢复对萨热克巴依次级盆地沉积环境的判定提供了沉积水体性质方面的依据,根据本文分析得出古盐度相对较高的半咸水沉积环境更有利于富集成矿.

Though the analysis of clay-minerals,major and trace elements of the Jurassic mudstone samples collectedfrom Sareke copper deposit.Palaeosalinity character of water environment when this mudstone was deposited inthese regions was revealed.By quantitative semiquantitative analysis involving calculation using Wallker-equivalent-boron determinate method suggested by Walker and strontium-barium ratio method.The results indicate the rangeof Palaeosalnity is 0.37%to 3.16%,and display that the majority of mudstone sample show semi-salt-water sedimentaryenvironment and freshwater brackish environment is secondary while salt-water environment is less in plane view,The Kezilesu formation of the Lower cretaceous ages shows the minimal palaeosalinity concentration in the centerand the maximal in the Juratal essential groups and in the on Jura library transcribing Gongsu group is moderate.The palaeosalinity of mudstone deposition in sediments is one of the indications to determine the sedimentaryenvironment,it can provide important reference in the aspects of water character for Sareke copper deposit.Theanalysis show that higher paleosalinity is conducive to copper enrichment.