内蒙古野芨里镁铁质—超镁铁质岩体的岩石地球化学特征  

Petrological and Geochemical Characteristics of Yejili Mafic-ultramafic Intrusion,Inner Mongolia

作　　者：闫海卿[1] 汤中立[1] 焦建刚[1] 耿科[2] 潘振兴[1] 

机构地区：[1]长安大学地球科学与国土资源学院,陕西西安710054 [2]中国地质大学地球科学与资源学院,北京100083

出　　处：《现代地质》2005年第4期515-521,共7页Geoscience

基　　金：中国地质调查局综合研究项目"中国超大型镍铜铂岩浆硫化物矿床预测研究"(200110200058)

摘　　要：野芨里岩体分布于金川铜镍(铂)硫化物矿床北偏东约100 km处,位于内蒙古境内.岩体主要由单斜辉石橄榄岩、二辉橄榄岩、辉长岩和闪长岩组成.岩体的稀土元素配分模式显示轻稀土元素略为富集,曲线为近于平坦型,w(La)N/w(Yb)N=1.866～2.713,不具备会聚型板块边缘玄武岩的特点;SNd(t)＞0,为亏损地幔源区特征.Mg#值和Ni丰度显示其为岩浆早期阶段堆晶作用的产物.与金川矿区超镁铁质岩体比较,二者均为华北大陆边缘成矿系统的组成部分,m/f值显示二者主要为铁质超基性岩,稀土元素及微量元素显示其具相似的地球化学特征,但野芨里岩体具早期堆晶就地熔离的特征,而金川岩体具有深部熔离-多期贯入的特征;野芨里岩体中Ni相对亏损.这些特征表明野芨里岩体具成矿的可能性.Yejili intrusion in Inner Mongolia is situated at the 100 km northeast of Jinchuan Cu-Ni-PGE sulfide deposit. It consists of wehrlite, lhezolite, gabbro and diorite. The REE distribution pattern shows weak LREE richment characteristics, （La/Yb） N = 1. 866 -2. 713, which are different from the characteristics of convergent plate marginal basalt, εNd （t） 〉 0 shows that the sources of magma come from depleted mantle. The value of Mg^# and Ni content in the intrusion show that it formed through crystal cumulus processes. Yejili intrusion and Jinchuan intrusion all belong to the continental-margin metallogenetic system of North China Craton. They have the same geochemical characteristics in m/f value, rare earth elements and trace elements. The nickel content in the Yejili intrusion is depleted. These characteristics show there is a potential forming of Cu-Ni sulfide deposits in the Yejili intrusion.

关 键 词：野芨里岩体 岩石地球化学特征 CU-NI硫化物矿床 金川 内蒙古 

分 类 号：P588.12[天文地球—岩石学]