Shear zone-controlled post-magmatic ore formation in the Huangshandong Ni–Cu sulfide deposit, NW China
Shear zone-controlled post-magmatic ore formation in the Huangshandong Ni–Cu sulfide deposit, NW China
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黄山东镍铜硫化物矿床剪切带控制的岩浆后成矿
DOI：
10.1016/j.oregeorev.2017.02.015
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发表时间：
2017-02
影响因子：
3.3
通讯作者：
Ben Dang
中科院分区：
文献类型：
--
作者：
Tao Yang;Ru-Xiong Lei;Zhi-Yong Zhu;Ben Dang
黄山东镍铜硫化物矿床位于中亚造山带东天山觉罗塔格岛弧带，位于康古尔—井尔泉韧性剪切带。黄山东镁铁质-超镁铁质岩体呈纺锤形，据信在区域韧性剪切带发育过程中侵入了强烈叶状的晚石炭世火山岩。矿床中部分矿体表现出强烈的韧性变形。其中17号矿体完全受韧性剪切带控制和赋存。该矿体的母岩和矿石变形蚀变剧烈，可称为矿石糜棱岩。此外，在韧性剪切带的富铜碳酸盐硫化物脉中可以观察到大量的网状细脉。野外地质调查和矿石学研究表明，黄山洞硫化物矿石由未变形岩浆矿、变形岩浆矿和热液叠印矿三类组成。具有网状结构的岩浆矿石未发生蚀变和变形，其中的硫化物矿物仅表现出脆性断裂。变形岩浆矿石中的硅酸盐和硫化物矿物具有强烈变形组构的特征。此类织物的例子有扭结带、乌拉长石的波状消光、金云母的多米诺结构以及磁黄铁矿和镍黄铁矿的细长颗粒。热液套印矿石的特点是变形强烈、晶粒扁平、磁黄铁矿再结晶；此外，经常观察到磁黄铁矿的退火。热液套印矿石中的磁黄铁矿、镍黄铁矿和黄铜矿分别具有较高的磁黄铁矿中的 Ni 和 Co 浓度、较高的镍黄铁矿浓度以及较高的 Ag 和 Cd 浓度。我们将流体叠印矿石中的Ni和Co归因于橄榄石的蚀变，而原生黄铜矿的溶解是富含黄铜矿的热液叠印矿石中铜的可能来源。黄山东岩体侵入冷却过程中，强烈的区域性韧性剪切作用，使矿床中硫化物矿石发生韧性变形，形成矿石糜棱岩。变形矿体中的脉石矿物被破碎为细粒矿物，并蚀变为蛇纹石、绿泥石和乌拉石。在这些过程中，流体和矿石元素被释放并与变形的岩石和矿石发生反应，在热液套印矿石上形成网状细脉。
The Huangshandong Ni–Cu sulfide deposit, located in the Kangguer–Jing’erquan ductile shear zone, belongs to the Jueluotage island arc belt in Eastern Tianshan of the Central Asian Orogenic Belt. The Huangshandong mafic–ultramafic pluton, which has a fusiform shape, is believed to have intruded strongly foliated Late Carboniferous volcanic rocks during the development of the regional ductile shear zone. Some orebodies in the deposit show intense ductile deformation. Among them, the No. 17 orebody is entirely controlled and hosted by the ductile shear zone. Host rocks and ores from this orebody show intense deformation and alteration, and could be called ore mylonites. Furthermore, numerous anastomosing veinlets can be observed in copper-rich carbonate-sulfide veins in the ductile shear zone. Geological field investigation and ore petrography studies indicate that sulfide ores at Huangshandong are composed of three types: undeformed magmatic ores, deformed magmatic ores, and hydrothermal overprinted ores. Magmatic ores with net fabrics remain unaltered and undeformed, and sulfide minerals in them show only brittle fractures. Silicate and sulfide minerals in deformed magmatic ores are characterized by intense deformation fabrics. Examples for such fabrics are kink bands, wavy extinction of uralite, domino structure of phlogopite, and elongated grains of pyrrhotite and pentlandite. Hydrothermal overprinted ores are characterized by strong deformation, flattened grains, and recrystallization of pyrrhotite; moreover, annealing of pyrrhotite is frequently observed. Pyrrhotite, pentlandite, and chalcopyrite in hydrothermal overprinted ores have high Ni and Co concentrations in pyrrhotite, a higher Ni concentration in pentlandite, and high Ag and Cd concentrations, respectively. We attribute Ni and Co in fluid-overprinted ores mainly to the alteration of olivine, and the dissolution of primary chalcopyrite is the likely source of copper in chalcopyrite-rich hydrothermal overprinted ores. During the intruding and cooling of the Huangshandong pluton, intense regional ductile shearing caused the ductile deformation of sulfide ores in the deposit, and subsequently, ore mylonites were formed. Gangue minerals in the deformed orebodies were crushed to fine-grained minerals and altered to serpentine, chlorite, and uralite. During these processes, fluid and ore elements were released and reacted with deformed rocks and ores, forming anastomosing veinlets on hydrothermal overprinted ores.
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影响因子：
2.6
作者：
B. Su;K. Qin;P. Sakyi;Dongmei Tang;Ping Liu;S. Malaviarachchi;Qing-Hua Xiao;He Sun
通讯作者：
B. Su;K. Qin;P. Sakyi;Dongmei Tang;Ping Liu;S. Malaviarachchi;Qing-Hua Xiao;He Sun
影响因子：
4.8
作者：
Ya-Jing Mao;K. Qin;Chusi Li;Dongmei Tang
通讯作者：
Ya-Jing Mao;K. Qin;Chusi Li;Dongmei Tang
影响因子：
4.8
作者：
J. Mukwakwami;B. Lafrance;C. Lesher;D. Tinkham;N. Rayner;D. Ames
通讯作者：
J. Mukwakwami;B. Lafrance;C. Lesher;D. Tinkham;N. Rayner;D. Ames
影响因子：
0.9
作者：
C. Almeida;G. Olivo;Sebastiao Gomes de Carvalho
通讯作者：
C. Almeida;G. Olivo;Sebastiao Gomes de Carvalho
DOI：
--
发表时间：
1981-06
期刊：
--
影响因子：
--
作者：
D. Vaughan;J. Craig
通讯作者：
D. Vaughan;J. Craig