投稿时间：2011-10-13
修订日期：2012-06-01
中文摘要:对辽西河坎子地区与碱性杂岩体相关的钼多金属矿床进行了同位素年代学研究。所获黑云母正长花岗岩锆石LA-ICP-MS U-Pb同位素加权平均年龄为(235.3±1.0) Ma,MSWD值为0.68;河坎子钼多金属矿床内辉钼矿的Re-Os同位素等时线年龄为(224.0±1.3) Ma,MSWD值为0.72。碱性杂岩体与相关的钼多金属矿床具有密切的空间关系,两者的形成时间亦比较接近,据此可推测,河坎子碱性杂岩体与相关的钼多金属矿床均为印支期构造-岩浆作用及流体活动的产物。印支期内频繁的岩浆-热液活动为该地区内钼、铜、金多金属元素的活化、迁移、富集提供了充足的热源条件。古大陆内部伸展构造环境中的碱性岩浆作用及流体活动为钼多金属矿床的形成提供了动力、物质和流体来源。
Abstract:The newly discovered Hekanzi deposit is a medium-size porphyry molybdenum deposit in western Liaoning Province. Intrusive complexes are widely distributed in the study area, with the Mesozoic alkaline and calc-alkaline rocks being the most developed alkaline rocks. They intruded into the Precambrian and Paleozoic volcanic-sedimentary rocks in the forms of batholiths, stocks, and dykes. Alkaline intrusive rocks are mainly miascite, alkaline syenite and alkaline diabase. The calc-alkaline rocks are mainly granite porphyry, granodiorite, biotite granite and K-feldspar granite. Isotopic ages of the Hekanzi alkaline granite and its related Mo polymetallic deposit have been determined. The rock-forming age of the biotite-orthoclase granite is (235.3±1.0) Ma with MSWD value of 0.68. Re-Os isotopic data of six molybdenite separates define a correlation line corresponding to an age of (224.0±1.3) Ma with MSWD value of 0.72. The metallic minerals in the ore are pyrite, chalcopyrite, molybdenite, pyrrhotite, marcasite and a little scheetine. Gangue minerals are mainly calcite, fluorite, garnet, serpentine, peridotite, dolomite, feldspar, plagioclase and quartz. The NE-trending, NS-trending and NW-trending fault zones are widely distributed in the alkaline intrusive complex and its related molybdenum polymetallic deposit at Hekanzi.
keywords:geochemistry zircon LA-ICP-MS U-Pb dating molybdenite Re-Os isotopic dating molybdenum polymetallic deposit alkaline intrusive complex Hekanzi western Liaoning Province
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中图分类号：P618.65
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基金项目:本文得到国家重点自然科学基金项目(编号: 41030421)和地质调查项目(编号: 1212010911029)的资助
引用文本：
刘勇,聂凤军,方俊钦.2012.辽西河坎子碱性侵入杂岩体及钼多金属矿床同位素年代学研究[J].矿床地质,31(6):1326~1336LIU Yong,NIE FengJun,FANG JunQin.2012.Isotopic age dating of the alkaline intrusive complex and its related molybdenum polymetallic deposit at Hekanzi, western Liaoning Province[J].Mineral Deposits31(6):1326~1336
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