【摘要】 东天山是中国最重要的岩浆铜镍硫化物矿带之一,产有黄山东、黄山、香山、葫芦等大中型铜镍矿床。图拉尔根、白石泉两处镍铜矿床为近年来在新疆地区铜镍找矿中的重大发现,两者均属于与镁铁质-超镁铁质杂岩有关的岩浆熔离-贯入型矿床。矿物共生组合以磁黄铁矿+镍黄铁矿+黄铜矿为特征,磁黄铁矿系矿石中最主要组成部分。文章以X射线衍射、扫描电镜、电子探针分析并辅以常规显微镜,查明这些矿床中磁黄铁矿均系Co、Ni的最主要载体矿物,Co、Ni元素主要以游离状态的硫化物(或硫砷化物)形式存在,如镍辉砷钴矿、钴辉砷镍矿、镍黄铁矿及紫硫镍矿等矿物。它们多以微细包裹体或出溶体形式随机地分布于磁黄铁矿内部,而少量的Co、Ni元素则以类质同像方式存在于磁黄铁矿晶格之中。图拉尔根、白石泉、葫芦三矿床中磁黄铁矿在多型结构以及微量元素地球化学方面均表现出一定的差异,系由两矿床容矿岩石基性程度及成矿温度之差异引起。更多还原

【Abstract】 Being one of the most important copper-nickel ore belts in China,the East Tianshan area has such medium-large size Cu-Ni deposits as Huangshan,Huangshandong,Xiangshan and Hulu.As the most important latest discoveries in East Tianshan,the Tulargen and Baishiquan Ni-Cu-Co deposits are magmatic differentiated deposits associated with Early Permian mafic-ultramafic complexes of post-collision stage.Ore minerals are dominated by pyrrhotite,pentlandite,chalcopyrite and pyrrhotite.By means of X-ray diffraction analysis,SEM and electron probe microanalysis combined with microscope observation,the authors found that Co and Ni are mainly hosted by pyrrhotite.Co and Ni exist in the form of cobaltine,pentlandite,Co-gersdorffite and violerite.These minerals are mainly randomly distributed within pyrrhotite as fine inclusions and exsolution,and minor Co-Ni exists in pyrrhotite crystal lattices as isomorphism.Due to the difference of basic extents of host rocks and crystallization and deposition temperatures,there exist some differences in trace elements and mineral super-lattices of pyrrhotite.Explosion temperature measurements of sulfides are consistent with results of different temperature facies of pyrrhotite.Ore-forming temperatures of Tulargen(313～394℃)and Hulu(311～433℃)Cu-Ni deposits with high-temperature hexagonal pyrrotite are higher than those of the Baishiquan Cu-Ni deposit(313～376℃)with low-temperature monoclinic pyrrotite.The lower the ore-forming temperature in these Cu-Ni deposits,the richer the Ni content of pyrrotite,with the highest being in the Baishiquan Cu-Ni deposit.Moreover,the higher the Ni/Fe ratio of pentlandite,the earlier its formation;the lower the Ni/Fe ratio of pentlandite,the later its formation.The discovery of troilite in the Baishiquan ore deposit is of genetic significance in mantle origin.更多还原