摘要
新疆萨热克大型铜矿床含矿地层为上侏罗统库孜贡苏组砂砾岩,与下伏下-中侏罗统煤矿形成"同盆共存"现象。萨热克铜矿石中碎裂岩化发育,并伴有沥青化,金属硫化物以辉铜矿为主,含少量的斑铜矿和黄铜矿等,多与次生石英-方解石等沿砾石裂隙分布。矿石中辉铜矿δ34S=-19.1‰^-13.2‰,辉铜矿206Pb/204Pb比值范围为16.699~18.417,207Pb/204Pb为15.294~15.684,208Pb/204Pb为36.909~38.996。次生石英流体包裹体的δ18OH2O值变化范围为17.9‰~20.6‰,δDV-SMOW变化范围为-82.6‰^-52.4‰。矿石中沥青δ13C变化范围为-20.79‰^-20.35‰,康苏组煤岩δ13CV-PDB值变化范围为-24.7‰^-24.3‰,两者较为接近。上述结果表明萨热克铜矿床中的硫源自地层中大量硫酸盐的还原作用,铅同位素指示成矿金属元素具有多元性,次生石英中成矿流体以变质流体为主,矿石中的沥青等有机质与下伏中-下侏罗统煤层等烃源岩有关。上述同位素资料结合矿床的地质特征显示萨热克铜矿床具有多期多阶段的成矿特征。
In the Sareke basin, there is a large copper deposit hosted in Upper Jurassic glutenite and a coal mine hosted in Lower-Middle Jurassic strata. In copper orebody, chalcocite, calcite and secondary quartz usually show occurrence of veinlet or stockwork filled in the interval among the different kinds of gravel consisted of quartzite, mudstone, carbonatite, and so on. In addition, the orebody near fault usually contains higher contents of asphalt. In this paper, we choose chalcocite and secondary quartz separated from copper ore for sulfur, lead, hydrogen and oxygen isotope analysis in order to judge the ore-forming material source of Sareke copper deposit. The 634S of chalcocite from copper ore ranges from -19.1%o to -13.2‰; The ratio of 206pb/204pb ranges from 16.699 tol8.417;the ratio of 207pb/204pb ranges from 15.294 to 1 5.684, and the ratio of 208pb/204pb ranges from 36.909 to 38.996. The δ18Oand 6D of the fluid inclusion in secondary quartz range from 17.9‰ to 20.6‰ and from -82.6‰ to -52.4‰, respectively. The δ13C of coal mine in the Kangsu Formation of Lower Jurassic strata ranges from -24.7‰ to -24.3‰, which is similar to the δ13C of asphaltum in copper ore ranging from-20.79‰ to-20.35‰. These isotopic analysis results indicate that sulfur is mainly derived from biological reduction of the strata sulfate; the lead shows the obviously multiple features; the metallogenic fluid of secondary quartz are mainly derived from metamorphic fluid; the asphaltum in copper ore are closely related to the coal-beating source rocks of Lower-Middle Jurassic strata. According to geological characteristics and the isotope data, we think that the metallogenic process of Sareke copper deposit shows multiphase and multi-stage mineralization during the period from the Upper Jurassic to the Lower Cretaceous.
作者
贾润幸
方维萱
胡雷雷
刘得磊
李述国
陈腾
JIA Run-xing;FANG Wei-xuan;HU Lei-lei;LIU De-lei;LI Shu-guo;CHEN Teng(China Non-ferrous Metals Resource Geological Survey, Beijing 100012, China;College of Earth Science and Resources, Chang＇an University, Xi ＇an 710054, China;College of Geology and Mineral Exploration engineering, Xinjiang University, Urumqi 830049, China)
出处
《矿物学报》
CSCD
北大核心
2017年第5期630-637,共8页
Acta Mineralogica Sinica
基金
中国地质调查局地质调查项目(编号:12120114081501)
国土资源部公益性行业科研项目(编号:201511016)
关键词
成因
稳定同位素
砂砾岩型
萨热克铜矿床
新疆乌恰
genesis
stable isotope
glutenite type
Sareke copper deposit
Wuqia, Xinjiang
