【摘要】 兴地镁铁—超镁铁质岩带位于塔里木克拉通北缘的库鲁克塔格地块，由兴地Ⅰ号、Ⅱ号、Ⅲ号和Ⅳ号等岩体组成。其中，兴地Ⅰ号和Ⅳ号岩体以辉长岩相为主；而兴地Ⅱ号和Ⅲ号岩体从橄榄岩相、辉石岩相到辉长岩相均有产出，岩相分带清楚。兴地Ⅱ号和Ⅲ号岩体二辉橄榄岩和二辉岩中均赋存有铜镍硫化物矿（化）体，常见矿石构造有星点状、斑点状、稀疏浸染状和稠密浸染状等，金属硫化物以磁黄铁矿、镍黄铁矿和黄铜矿为主。兴地Ⅱ号和Ⅲ号岩体岩石的铂族元素（PGE）含量（质量分数，下同）(（0.41～4.54）×10^-9)低，钯组铂族元素（PPGE）含量总体高于铱组铂族元素（IPGE）,IPGE/PPGE值为0.08～0.48,原始地幔标准化铂族元素蛛网图呈左倾型。岩石中铂族元素相对于Ni和Cu明显亏损，Pd/Ir值为3.28～23.33,Ni/Cu值为3.67～10.00,表明其母岩浆为高镁玄武质岩浆，这与橄榄石-熔体平衡估算的母岩浆性质一致。全岩Cu/Pd值（（6.58～83.33）×10⁴）以及Cu/Zr值与Ni含量的相关性特征表明，在岩浆源区和侵位过程中均发生了硫化物的熔离作用，导致残余岩浆中显著亏损铂族元素。综合分析认为，兴地Ⅱ号和Ⅲ号岩体具有良好的找矿前景。更多还原

【Abstract】 Xingdi mafic-ultramafic rock belt in the northern Tarim craton is composed of No.Ⅰ, No.Ⅱ, No.Ⅲ and No.Ⅳ intrusions. The lithology of Xingdi No.Ⅰ and No.Ⅳ intrusions is mainly gabbro facies, while Xingdi No.Ⅱ and No.Ⅲ intrusions have various rocks of olivine, pyroxenite and gabbro facies, and the lithofacies zonation is clear. The Cu-Ni sulfide ore bodies are mainly hosted in lherzolite and websterite of Xingdi No.Ⅱ and No.Ⅲ intrusions, and the Cu-Ni sulfide ores are stellate, speckled, sparse-disseminated and dense-disseminated in structure. Most of the sulfides occur as aggregate of pyrrhotite, pentlandite and chalcopyrite. The total contents of platinum group element（PGE） are（0.41-4.54）×10^-9 of bulk rocks in Xingdi No.Ⅱ and No.Ⅲ intrusions, which are lower than that of primitive mantle and show positive correlations with MgO contents. The contents of IPGE（Os, Ir and Ru） are slightly higher than that of PPGE（Ru, Pt and Pd） with IPGE/PPGE ratios of 0.08-0.48, and primitive mantle-normalized PGE spider diagrams of rocks are left-declined pattern. Their Pd/Ir and Ni/Cu ratios range from 3.28 to 23.33 and from 3.67 to 10.00, respectively, indicating that parental magmas of Xingdi No.Ⅱ and No.Ⅲ intrusions are high-Mg basaltic. It is consistent with the result estimated from olivine-melt equilibrium. According to bulk rock Cu/Pd ratio（（6.58-83.33）×10⁴） and correlation between Cu/Zr and Ni, it is concluded that sulfide dissociation occurs in the source and during emplacement, resulting in a significant loss of PGE in remnant magma. It is comprehensively concluded that Xingdi No.Ⅱ and No.Ⅲ intrusions have good prospecting prospect.更多还原