中国西北地区岩浆铜镍矿床地质特点与找矿潜力  

Geological Characteristics and Prospecting Potential of Magmatic Ni-Cu Sulfide Deposits in Northwest China

作　　者：张照伟[1] 钱兵[1] 王亚磊[1] 李文渊[1] ZHANG Zhaowei;QIAN Bing;WANG Yalei;LI Wenyuan(Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits,MNR,Xi'an Center of CGS,Xi'an 710054,Shaanxi,China)

机构地区：[1]自然资源部岩浆作用成矿与找矿重点实验室,中国地质调查局西安地质调查中心,陕西西安710054

出　　处：《西北地质》2021年第1期82-99,共18页Northwestern Geology

基　　金：国家自然科学基金面上项目“东昆仑夏日哈木铜镍矿床硫化物不混溶作用研究”(41873053);第二次青藏高原综合科学考察研究“稀贵金属(金、镍、钴、铬铁矿、铂族元素)科学考察与远景评估”(2019QZKK0801);陕西省创新能力支撑计划-创新人才推进计划-岩浆作用成矿与找矿创新团队(2020TD-030);中国地质调查局地质调查项目“西昆仑大红柳滩-甜水海地区大型矿产资源基地综合调查”(DD20190143)资助成果。

摘　　要：西北地区是中国岩浆铜镍硫化物矿床最为发育的地区,主要有3个重要成矿期,其地质特点、成矿条件、形成标志等存在明显不同。笔者梳理了目前诸多学者对岩浆铜镍硫化物矿床的研究工作,并结合野外实际,发现大陆裂谷是形成巨型-超大型岩浆铜镍硫化物矿床的构造背景条件,铁质系列的镁铁-超镁铁质岩体才可能形成有经济价值的岩浆铜镍硫化物矿体。超壳深大断裂为地幔岩浆上涌提供了有利条件。分异良好的超基性岩体更具有成铜镍矿的潜力。结晶分异促进了硫化物饱和,地壳混染是成矿的关键。橄榄石和单斜辉石具有低的CaO和FeO含量的岩体,更有利于形成规模较大的岩浆铜镍硫化物矿体。这些研究认识与发现为理解西北地区镁铁-超镁铁质岩浆成矿作用过程、找矿潜力预测及找矿方向和找矿空间提供了技术支撑与资料基础。Northwest China is the most developed area of magmatic Ni-Cu sulfide deposits in China.There are mainly three important metallogenic periods.The geological characteristics,mineralization condition and formation indicators of these three periods are obviously different.This paper summarizes the current researches on the magmatic Ni-Cu sulfide deposits.On the basis of field investigation,the authors found that the tectonic background for the formation of giant or super-large magmatic Ni-Cu sulfide deposits is the continental rifts.Only the ferruginous ultramafic intrusion has the potential to be an economically-valuable deposit.The deep and large cut-through crust faults provide favorable conditions for the upwelling of mantle magma.The well-differentiated ultramafic-ultramafic complex has the potential to hold the Ni-Cu ore.Crystal differentiation promotes sulfide saturation,and crustal sulfur contamination is the key to mineralization.The complex of olivine and clinopyroxene with the low CaO and FeO content are more conducive to the formation of magmatic Ni-Cu sulfide deposit.The findings lay a foundation for the direction and the prospecting potential of mafic-ultramafic magmatic mineralization in Northwest China.

关 键 词：镁铁-超镁铁质岩 铜镍矿 地质特点 找矿潜力 西北地区 

分 类 号：P618.41[天文地球—矿床学] P618.63[天文地球—地质学]