新疆萨热克砂砾岩型铜矿床富烃类还原性盆地流体特征

发布时间：2019-03-17 11:33

【摘要】：新疆萨热克大型砂砾岩型铜矿床含矿地层为上侏罗统库孜贡苏组,与下伏下-中侏罗统煤矿形成"同盆共存"现象。在萨热克铜矿床的铜矿体内,构造裂隙中含较多沥青(有机碳含量达0.11%~2.55%),并与辉铜矿等铜硫化物共生。铜矿石中次生石英、方解石和白云石等胶结矿物包裹体含烃盐水类、含烃盐水-液烃共生类、含烃盐水-气烃共生类、轻质油类等四类富烃类盆地流体的包裹体。研究认为铜矿石中的有机质主要来源于下伏烃源岩煤层,当盆地深部富含有机质的还原性流体沿NE向构造裂隙上侵到渗透率较高的上侏罗统库孜贡苏组上段(J3kz2)砂砾岩层时,该层上部的下白垩统克孜勒苏群下段(K1kz1)褐红色粉砂质泥岩,与下部的上侏罗统库孜贡苏组下段(J3kz1)灰绿色粉砂质泥岩形成封闭的隔水层,还原性流体沿砂砾岩层发生水平渗滤扩散,与盆地中封存的地层水淋滤含铜赤铁矿质砾岩类后形成的含铜氧化相流体混合时,造成了辉铜矿的大量沉淀和碳酸盐等矿物的结晶析出,并沿砾石间隙充填分布。
[Abstract]:The ore-bearing strata of the large-scale sandstone-gravel type copper deposit in Sarek, Xinjiang, are the Kuzigongsu formation of the Upper Jurassic, which formed a "coexisting in the same basin" phenomenon with the lower-middle Jurassic coal mines. In the copper deposit of Sarek copper deposit, the structural fissure contains more bitumen (0.11% ~ 2.55% organic carbon) and coexists with copper sulphide such as chalcopyrite. The inclusions of secondary quartz, calcite and dolomite in copper ores contain hydrocarbon-bearing saline, hydrocarbon-bearing brine-liquid hydrocarbon symbiosis, hydrocarbon-bearing brine-gas hydrocarbon symbiosis, light oil and other hydrocarbon-rich basin fluid inclusions. It is considered that the organic matter in copper ore mainly comes from the coal seam of underlying source rock. When the reductive fluid rich in organic matter in the deep part of the basin invades the NE-trending tectonic fissure to the upper member of the Kuzigongsu formation (J3kz2) with high permeability, it is considered that the source rock is mainly from the coal seam of the underlying source rock. The upper part of the lower Cretaceous Kizilesu group (K1kz1) brown-red silty mudstone and the lower part of the upper Jurassic Kuzigongsu formation (J3kz1) gray-green silty mudstone formed a closed water-proof layer. When the reductive fluid is leached and diffused horizontally along the gravel layer and mixed with the copper-bearing oxidation phase fluid formed by leaching the copper-bearing red iron ore conglomerate with the sealed formation water in the basin, A large amount of precipitate of chalcopyrite and crystallization of carbonate and other minerals were precipitated and distributed along gravel gap.
【作者单位】：有色金属矿产地质调查中心;
【基金】：新疆萨热克铜矿整装勘查区专项填图与技术应用示范(12120114081501) 塔西砂砾岩型铜铅锌矿床成矿规律与找矿预测(201511016)联合资助
【分类号】：P618.1;P618.41

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