本文对新疆黄山-镜儿泉铜镍成矿带中黄山东岩体进行了主量元素、微量元素和Sr-Nd同位素的研究,探讨了岩体成因和区域构造演化.黄山东岩体有三次岩浆侵入,第一次侵入形成了橄榄辉长岩、角闪辉长岩和闪长岩,构成岩体的主体,其中橄榄辉长岩位于岩体中部,角闪辉长岩位于岩体上部和下部,闪长岩沿岩体边缘分布；第二次侵入形成辉长苏长岩,呈岩墙状分布于岩体西端和西北部；第三次侵入岩石为二辉橄榄岩,位于岩体下部,为主要的赋矿岩相.黄山东岩体样品除橄榄辉长岩和角闪辉长岩TiO2含量之外主量元素投影点都处于橄榄石、单斜辉石、斜方辉石和斜长石矿物化学成分之间,指示它们主要由橄榄石、单斜辉石、斜方辉石和斜长石组成.与塔里木地区地幔柱成因二叠纪镁铁-超镁铁岩体相比,黄山东岩体亏损Nb、Ta、Ti等高场强元素,La、Ba、Th、U等不相容元素含量较低,ENd (t)较高(+7.32‰～+8.29‰),并且具有较低的Th/U比值(1.13～2.98)和Nb/U比值(2.53～7.02),较高的La/Nb比值(1.15～4.19)和Ba/Nb比值(37.7～79.8).这些特征与俯冲成因的火山岩和侵入岩相似,暗示其原始岩浆主要来源于受俯冲流体交代地幔的部分熔融,软流圈地幔的上涌可能为部分熔融提供了热源.%The major and trace elements and Sr-Nd isotopes of the Huangshandong mafic-ultramafic intrusion in the Huangshan-Jing'erquan magmatic Cu-Ni mineralization belt are discussed to constrain its formation and regional tectonic evolution. Three magmatic pulses of the Huangshandong intrusion have been identified. The first pulse formed olivine gabbro, hornblende gabbro and diorite, which constitute the main body of the complex, with olivine gabbro in the central section, hornblende gabbro in upper and lower parts, and olivine gabbro along the margin of the complex. The second pulse formed gabbronorite dykes occurring as dykes in the western and northwestern parts of the intrusion. Iherzolite, the product of the third magmatic pulse is distributed at the bottom of the complex and is the main host rock for the Cu-Ni ores. Except TiO2 contents in olivine gabbro and hornblende gabbro, all other major elements of the samples from the Huangshandong intrusive rocks are plotted within compositons of olivine, orthopyroxene, clnopyroxene and plagioclase, indicating that the complex consists predominantly of rock-forming minerals. Compared with the Permian mantle plume-derived mafic-ultramafic intrusions in Tarim, the Huangshandong intrusion is characterized by deplete high field-strength elments ( HFSE) (Nb, Ta and Ti) and incompatible elements (La, Ba, Th, U) , but higher ∈Nd(t) (7. 32‰~8. 29‰), low Th/V ratio (1. 13~2. 98) and Nb/U ratio (2. 53~7. 02), and high La/Nb ratio (1. 15~4. 19) and Ba/Nb (37. 7~79. 82). These features are similar to those of subduction-related extrusive and intrusive rocks, indicating that the primitive magma for the Huangshandong intrusion was the result of partial melting of a metasomatic mantle modified by the subducted slab-derived melt/fluid and upwelling of asthensphere mantle may provide heat source for the partial metling.
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