投稿时间:2017-10-05
修订日期:2018-05-03
网络发布日期:2018-09-10
中文摘要:五龙矿床是中国辽东地区最大的石英脉型金矿床,赋存于中生代黑云母花岗岩中。金矿体多呈脉状产出,与中生代细粒闪长岩有成因联系。文章采用LA-ICP-MS锆石U-Pb定年方法,获得矿区内黑云母花岗岩、花岗斑岩、细粒闪长岩的结晶年龄分别为(155.4±0.9)Ma、(154.2±1.2)Ma、(123.1±0.9)Ma。文章选取金矿石中绢云母样品开展了Ar-Ar定年,获得Ar-Ar坪年龄为(122.8±0.8)Ma(MSWD=0.09)。金属硫化物的δ34S值介于+1.1‰~+2.4‰,平均值为+1.8‰,表明硫主要来自深源岩浆。黄铁矿中流体包裹体3He/4He比值为0.36~0.65Ra,平均值为0.50 Ra,表明地幔流体参与成矿作用的比例为3.9%~7.2%,地壳流体占主导地位。五龙金矿的成矿时代为早白垩世,形成于华北克拉通东部的构造体制转折和大规模岩石圈减薄背景。
中文关键词:地球化学 锆石U-Pb定年 绢云母Ar-Ar定年 五龙金矿 华北克拉通
Abstract:The Wulong deposit is the largest quartz vein type gold deposit in eastern Liaoning Province. The orebodies are hosted in the Mesozoic biotite granite. The orebodies occur as veins, which have a genetic relation to the Mesozoic fine-grained diorite. The high precision LA-ICP-MS zircon U-Pb dating method wasadopted to measure the ages of the biotite granite, granite porphyry and fine-grained diorite in the Wulong deposit, which yielded (155.4±0.9) Ma, (154.2±1.2) Ma and (123.1±0.9) Ma, respectively. A sericite sample in gold ore was selected for the Ar-Ar dating method to determine the mineralization age of the Wulong gold deposit. An Ar-Ar plateau age defined by a sericite sample yielded an age of (122.8±0.8) Ma (MSWD=0.09). The δ34S values of metallic sulfides range from +1.1‰ to +2.4‰, with an average of +1.8‰, suggesting that the sulfur came mainly from deep magma. 3He/4He ratios of fluid inclusions in pyrite range from 0.36 to 0.65 Ra with an average of 0.50 Ra. The mantle helium involved in the ore-forming fluid is 3.9% to 7.2%, suggesting the dominance of the earth's crust fluid. The ore-forming age of the Wulong gold deposit is early Cretaceous. The Wulong deposit was formed in a tectonic regime transformation and lithosphere thinning setting in eastern part of the North China Craton.
keywords:geochemistry zircon U-Pb dating sericite Ar-Ar dating Wulong gold deposit North China Craton
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基金项目:本文得到国家重点研发计划项目(编号:2017YFC0601403)、国家自然科学基金项目(编号:41672066)和中国地质科学院基本科研业务费项目(编号:YYWF201512)联合资助
引用文本:
刘军,王树岭,李铁刚,杨艳,刘福兴,李生辉,段超.2018.辽宁省五龙金矿床成岩成矿年代学及同位素地球化学特征[J].矿床地质,37(4):712~728LIU Jun,WANG ShuLing,LI TieGang,YANG Yan,LIU FuXing,LI ShengHui,DUAN Chao.2018.Geochronology and isotopic geochemical characteristics of Wulong gold deposit in Liaoning Province[J].Mineral Deposits37(4):712~728
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