投稿时间:2018-01-09
修订日期:2018-07-04
网络发布日期:2018-11-03
中文摘要:钨矿往往与酸性或中酸性侵入岩相关,对于复式岩体通常仅与某一特定期次岩浆相关,如何确定成矿相关岩体是找矿勘查的一道难题。朱溪矽卡岩型钨矿床位于江南古陆钨矿带,是一个世界级钨矿床。该矿床的形成主要与黑云母二长花岗岩和细粒花岗岩密切相关,此次研究发现黑云母二长花岗岩中的黑云母发生蚀变、分解过程中形成了大量含W金红石(w(WO3)为0.01%~0.96%)。这类含W次生金红石同样出现在华南地区多个钨矿床的成矿相关岩体中,并且其WO3含量显著高于与岩浆作用相关的锡矿床和斑岩型铜(金)矿床中的次生金红石的WO3含量。此外,朱溪矿床中岩浆演化晚期形成的细粒花岗岩中结晶了一些自形板状的原生金红石,这些金红石同样显著富集W元素(w(WO3)为0.06%~1.12%)。金红石中的Ti容易被W所替代,导致(岩浆)热液体系所经历的W元素富集过程会被结晶的金红石所记录。因此,通过花岗质岩体中黑云母发生蚀变或分解后形成的次生金红石,或岩浆演化晚阶段形成的细晶岩脉中的原生金红石的W元素含量,可以判断岩浆结晶演化过程中是否经历过W元素的富集及相应的富集程度,从而判断花岗质岩体是否具备形成钨矿床的潜力。
Abstract:Tungsten deposits are commonly related to intermediate-acid intrusions. Identifying the ore-related intrusions is a challenge in mineral exploration, because complex rock bodies commonly appear in tungsten mines, but tungsten mineralization is commonly related to special magmatic activity. The Zhuxi W deposit, which is a worldclass deposit, is located in the Jiangnan porphyry-skarn tungsten belt. The formation of the Zhuxi deposit is closely related to biotite monzogranite and fine-grained granite. Studies revealed that the formation of a number of W-bearing rutile (0.01%~0.96%) crystals was accompanied by biotite decomposition. This process also occurred in several W deposits in South China. The hydrothermal rutile grains in W deposits exhibit much higher WO3 concentrations than the hydrothermal rutile grains in granite-related Sn deposits and porphyry Cu-Au deposits. In addition, some primary plate rutile crystals crystallized in the fine-grained granite from the residual granitic magma; these primary rutile grains also record high WO3 content (0.06%~1.12%). If a magma-hydrothermal system has undergone W enrichment, and the Ti site in rutile may be replaced by W, causing the rutile to record the enrichment of W in the system during its crystallization. Therefore, we can assess the metallogenetic potentiality of a granitic intrusion by measuring the W concentrations of the hydrothermal rutile that crystallized during the decomposition of biotite or the primary rutile that crystallized in the residual magma melt.
文章编号:
中图分类号:P618.66
文献标志码:
基金项目:本文得到国家自然科学基金项目(编号:41430314)和国土资源部成矿作用与资源评价重点实验室开放基金(编号:ZS1708)联合资助
引用文本:
宋世伟,毛景文,谢桂青,宋昊,陈国华,饶建锋,欧阳永棚.2018.矽卡岩型钨矿床成矿相关岩体识别——以江西景德镇朱溪超大型矽卡岩型钨矿床为例[J].矿床地质,37(5):940~960SONG ShiWei,MAO JingWen,XIE GuiQing,SONG Hao,Chen GuoHua,Rao JianFeng,OUYANG YongPeng.2018.Identification of ore-related granitic intrusions in W skarn deposits: A case study of giant Zhuxi W skarn deposit[J].Mineral Deposits37(5):940~960
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