Ore genesis of the Zhuxi supergiant W-Cu skarn polymetallic deposit, South China: Evidence from scheelite geochemistry
Ore genesis of the Zhuxi supergiant W-Cu skarn polymetallic deposit, South China: Evidence from scheelite geochemistry
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华南竹溪特大型钨铜矽卡岩多金属矿床成因：来自白钨矿地球化学的证据
DOI：
10.1016/j.oregeorev.2019.02.017
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发表时间：
2019-04
影响因子：
3.3
通讯作者：
Deng Jun
中科院分区：
文献类型：
--
作者：
Sun Keke;Chen Bin;Deng Jun
白钨矿是矽卡岩型钨矿床的主要矿石矿物，利用白钨矿可追踪成矿过程和成矿物质来源。朱溪钨铜存款（3.44 Mt WO_3，0.54%，0.10 Mt Cu，0.57%）位于江南造山带北方，是世界上最大的钨矿床之一。矽卡岩和矿体主要产于中生代高分馏侵入体与石炭纪碳酸盐沉积（黄龙组和船山组）的接触带内。结果表明，白钨矿中稀土元素主要受3Ca ~（2+）= 2 RE ~（3 + +）□Ca置换机制控制。竹溪存款白钨矿的稀土元素配分模式在退矽卡岩阶段表现为Eu正异常，在退矽卡岩阶段表现为Eu负异常。Eu异常的变化记录了成矿过程。Eu负异常继承于中生代花岗岩，Eu正异常形成于较还原的氧化还原环境。白钨矿从退变质阶段到退变质阶段，Mo含量沿着降低，δEu和δCe增加，支持了成矿流体氧逸度的时间性降低。竹溪存款白钨矿具有低εNd（t）值（−10.1 ~ −7.0）和高初始87 Sr/86 Sr比值（0.71231-0.72371）的特征，与以地幔贡献为主的脉状金钨矿床中的白钨矿不同。白钨矿的Nd-Sr同位素结果与三个中生代花岗岩的结果一致，表明它们之间的成因联系。白钨矿的Nb/Ta值介于中生代花岗岩和双桥山群变质沉积岩围岩之间，表明双桥山群对成矿作用也有贡献。这与普遍接受的成矿流体和金属仅从花岗岩中出溶的模式不同。
Scheelite is the main ore mineral in skarn-type tungsten deposits, which can be used to track the ore-forming processes and sources. The Zhuxi W-Cu deposit (3.44 Mt WO3 at 0.54% and 0.10 Mt Cu at 0.57%), located in the northern part of the Jiangnan orogen, is one of the largest tungsten deposits in the world. Skarn and orebodies occur mainly within the contact zone between the Mesozoic highly fractionated intrusions and Carboniferous carbonate sediments (Huanglong and Chuanshan formations). Our data reveal that the REEs of scheelite are mainly controlled by the substitution mechanism 3Ca2+ = 2REE3+ + □Ca. Scheelites from the Zhuxi deposit show negative Eu anomalies in the prograde skarn stage, but positive Eu anomalies in the retrograde skarn stage in the chondrite-normalized REE patterns. Variation of Eu anomalies recorded the ore-forming processes. The negative Eu anomalies were inherited from the Mesozoic granites and the positive ones formed under more reduced redox conditions. The decrease of Mo concentrations, along with increase of δEu and δCe of scheelite from prograde to retrograde skarn stage, support a temporal decrease in oxygen fugacity of the mineralization fluids. The scheelites from the Zhuxi deposit are characterized by low εNd(t) values (−10.1 to −7.0) and high initial 87Sr/86Sr ratios (0.71231–0.72371), which are different from the scheelites hosted in vein-type Au-W deposits contributed mainly by mantle. The Nd-Sr isotopes of scheelites are consistent with the results of the three Mesozoic granites, indicating their genetic relationship. However, the scheelites show variable Nb/Ta compositions, which straddle between the values of Mesozoic granites and the country rock of Shuangqiaoshan Group meta-sedimentary rocks, indicating the Shuangqiaoshan Group also has contributed to mineralization. This is different from a commonly accepted model that the ore-forming fluids and metals were exsolved exclusively from the granite plutons.
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影响因子：
3.3
作者：
Teng Ding;Teng Ding;D. Ma;Jian-Jun Lu;Rongqing Zhang;Rongqing Zhang
通讯作者：
Teng Ding;Teng Ding;D. Ma;Jian-Jun Lu;Rongqing Zhang;Rongqing Zhang
影响因子：
6.1
作者：
Yuejun Wang;W. Fan;Guowei Zhang;Yanhua Zhang
通讯作者：
Yuejun Wang;W. Fan;Guowei Zhang;Yanhua Zhang
影响因子：
5.8
作者：
A. Mueller;J. D. Laeter;D. Groves
通讯作者：
A. Mueller;J. D. Laeter;D. Groves
影响因子：
3.5
作者：
R. Thomas;H. Förster;K. Rickers;J. Webster
通讯作者：
R. Thomas;H. Förster;K. Rickers;J. Webster
影响因子：
3.1
作者：
Xinmin Zhou;T. Sun;W. Shen;L. Shu;Y. Niu
通讯作者：
Xinmin Zhou;T. Sun;W. Shen;L. Shu;Y. Niu