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现代地质 ›› 2005, Vol. 19 ›› Issue (4): 515-521.

• 岩石与矿物 • 上一篇    下一篇

内蒙古野芨里镁铁质--超镁铁质岩体的岩石地球化学特征

闫海卿1,汤中立1,焦建刚1,耿科2,潘振兴1   

  1. 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
  • 收稿日期:2005-04-15 修回日期:2005-09-15 出版日期:2005-04-20 发布日期:2005-04-20
  • 作者简介:闫海卿,男,讲师,博士,1963年出生,岩石学和矿床学专业,主要从事岩石学、矿床学的教学与研究工作。
  • 基金资助:

    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)

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

YAN Hai-qing1,TANG Zhong-li1,JIAO Jian-gang1,GENG Ke2,PAN Zhen-xing1   

  1. 1 College of Earth Science and Land Resource, Chang’an University,Xi’an, Shaanxi710054,China;
    2 School of Earth Sciences & Resources, China University of Geosciences, Beijing100083, China
  • Received:2005-04-15 Revised:2005-09-15 Online:2005-04-20 Published:2005-04-20

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;εNd(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。

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

Abstract:

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.

Key words: Yejili intrusion, petrological and chemical characteristics, Cu-Ni-PGE sulfide deposit, Jinchuan, Inner Mongolia

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