投稿时间：2012-03-15
修订日期：2013-02-07
中文摘要:新疆北部与幔源岩浆有关的矿床种类齐全,成矿环境复杂,时代和类型繁多,在中国乃至世界颇具特色。主要矿床类型包括铬铁矿矿床、钒钛磁铁矿矿床、铜镍硫化物矿床、铂族元素(PGE)矿床、铜镍-钒钛铁复合型矿床、含钴磁铁矿矿床、玄武岩自然铜矿床、热液型钴-多金属矿床,以及非金属矿床等。按照含矿地质体的类型,可分为6种类型:蛇绿岩型、层状杂岩型、小侵入体型、阿拉斯加型、浅成岩型和喷出岩型。这些幔源岩浆矿床可划分为3个成岩成矿系列:铜镍系列、钛铁系列和铬铁系列。钛铁系列以碱性层状岩体型钒钛磁铁矿、铁磷矿为代表,岩石具有明显的富Fe特征,属于碱性富铁质的高钛玄武岩系列;铜镍系列以小侵入体型铜镍矿、阿拉斯加型铜镍-PGE矿为代表,岩石属于铁质的拉斑玄武岩-钙碱性系列;铬铁系列主要为蛇绿岩型铬铁矿,岩石具富Mg贫Fe特征,属于镁质系列。3个系列的岩浆都具有亏损地幔源特征,可能都与地幔柱活动有关;岩浆源区富含相应的成矿元素,是形成3个系列矿床相应成矿地质体的主要条件。3个系列矿床的成矿机制可分为深部熔离/岩浆分异、就地分凝、矿浆贯入、岩浆热液等过程。根据各系列矿床之间存在的紧密联系,建立了与幔源岩浆作用有关的3个系列矿床综合模式: 亏损地幔部分熔融产生的幔源岩浆在上升过程中发生熔离/分异,分离为3个系列,由于外部物质加入在地壳深部发生分异和熔离,在不同深度富集形成铬铁矿、钒钛磁铁矿和铜镍硫化物矿床,临近地表时流体富集和分离成含矿流体,分别形成浅成岩型磁铁矿和喷出岩型自然铜矿。新疆北部各类幔源岩浆矿床从早到晚主要产于3期构造阶段/构造类型: 大陆裂解期、板块俯冲期、碰撞/后碰撞造山期(又分3个阶段: 碰撞后伸展阶段、幔柱叠加造山阶段、后碰撞结束阶段)。
Abstract:Mantle-derived magmatic ore deposits in northern Xinjiang are composed of chromite deposits, copper-nickel sulfide deposits, platinum group elements (PGE) deposits, Cu-Ni~V-Ti-Fe composite deposits, cobalt-bearing magnetite deposits, basalt-hosting native copper deposits, hydrothermal cobalt-polymetallic deposits and non-metallic deposits. According to types of ore-bearing magmatic bodies, these ore deposits can be classified into six types, i.e., ophiolite type, layered intrusion type, minor intrusion type, Alaska type, hypabyssal type and extrusive rock type. These mantle-derived magmatic ore deposits can be divided into three series, namely, copper-nickel, vanadium-titanium and ferrochrome series. Magmatic sources of these three series show significantly different features: the copper-nickel series with relatively abundant mafic tholeiitic basalts is significantly enriched in Cu, Ni and Co; the vanadium-titanium series with iron-rich alkali basalts is enriched in V, Ti and Fe; the ferrochrome series with magnesia-rich tholeiitic basalts is enriched in Cr. Therefore, the magmatic sources that had rich ore-forming elements and formed magmatic bodies constituted the main ore-forming conditions for these three series. The ore-forming mechanism of the three series can be divided into deep magmatic liquation and magmatic differentiation, in-situ liquation, ore magma injection and magmatic hydrothermal processes. Based on the close relationships between these series, we can construct the integrated metallogenic model of the ore deposits related to mantle-derived magma. Mantle-derived magma from depleted mantle partial melting source might have experienced melt segregation and/or fractionation processes during their ascent, resulting in the association of these three series with different ore deposits. The external material that participated in the magmatic evoluation in the deep crust could form chromite, vanadium-titanium magnetite and copper-nickel sulfide deposits at different depths. When the evolved magma reached somewhere near the surface, they might combine with enriched fluid and ore-bearing fluid to form subvolcanic magnetite and extrusive native copper deposits. The tectonic setting or tectonic stages of the ore deposits associated with mantle-derived magma in North Xinjiang can be classified into three types as follows: i) the continental rift stage, which yielded copper-nickel deposits related to minor intrusions and iron-phosphate deposits associated with alkaline layered intrusions; ii) the plate subduction stage, which yielded ophiolite-associated chromite deposits and Alaska type copper-nickel-PGE deposits; iii) collision or post-collision orogenic stage, which can be divided into three sub-stages/processes: the post-collision stretching process yielded the basalt-associated native copper deposits, the mantle plume superimpositon orogenic process yielded copper-nickel deposits related to minor intrusions and copper-nickel-vanadium-titanium-iron composite deposits related to layered intrusions, and the collision termination or cratonization process yielded hypabyssal Co-bearing magnetite deposits and vanadium-titanium magnetite deposits associated with small layered intrusions.
keywords:geology mantle-derived magmatic deposit mineralization type metallogenic series metallogenic lineage tectonic setting northern Xinjiang
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中图分类号：P612
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基金项目:本文得到国家自然科学基金项目(41030424)和国家重点基础研究发展计划"973"项目(2007CB411304, 2002CB409806)的联合资助
引用文本：
王玉往,王京彬,李德东,龙灵利,唐萍芝,石煜,高一菡.2013.新疆北部幔源岩浆矿床的类型、时空分布及成矿谱系[J].矿床地质,32(2):223~243WANG YuWang,WANG JingBin,LI DeDong,LONG LingLi,TANG PingZhi,SHI Yu,GAO YiHan.2013.Types, temporal-spatial distribution and metallogenic lineage of ore deposits related to mantle-derived magma in northern Xinjiang[J].Mineral Deposits32(2):223~243
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