地学前缘 ›› 2018, Vol. 25 ›› Issue (6): 308-329.DOI: 10.13745/j.esf.sf.2018.9.3

• 地质流体与成矿作用 • 上一篇    下一篇

迤纳厂矿床:一个“白云鄂博式”铁铜稀土矿床

温利刚,曾普胜,詹秀春,范晨子,孙冬阳,王广,袁继海,费晓杰   

  1. 1. 国家地质实验测试中心, 北京 100037 
    2. 北京矿冶科技集团有限公司, 北京 100160 
    3. 矿冶过程自动控制技术国家重点实验室, 北京 100160 
    4. 中国地质大学(北京), 北京 100083
  • 收稿日期:2017-12-24 修回日期:2018-08-25 出版日期:2018-11-30 发布日期:2018-11-30
  • 通讯作者: 曾普胜(1964—),男,博士,研究员,长期从事矿床学、岩石学和地球化学研究。E-mail:zengpusheng@vip.sohu.com
  • 作者简介:温利刚(1992—),男,硕士,主要从事矿床学及工艺矿物学自动测试技术研究。E-mail:yunwenligang@163.com
  • 基金资助:
    中国地质科学院基本科研业务费项目(YYWF201619,JYYWF20180101);中国地质调查局地质调查项目(DD20160220);国家自然科学基金项目(41072073);中国地质调查局地质调查项目(12120113002500);国土资源部公益性科研专项经费项目(201211078)

The Yinachang deposit in central Yunnan Province, Southwest China: A “Bayan Obo-type” Fe-Cu-REE deposit.

WEN Ligang,ZENG Pusheng,ZHAN Xiuchun,FAN Chenzi,SUN Dongyang,WANG Guang,YUAN Jihai,FEI Xiaojie   

  1. 1. National Research Center for Geoanalysis, Beijing 100037, China 
    2. Beijing General Research Institute of Mining and Metallurgy(BGRIMM) Technology Group, Beijing 100160, China 
    3. State Key Laboratory of Process Automation in Mining and Metallurgy, Beijing 100160, China 
    4. China University of Geosciences(Beijing), Beijing 100083, China
  • Received:2017-12-24 Revised:2018-08-25 Online:2018-11-30 Published:2018-11-30
  • Supported by:
     

摘要: 云南武定迤纳厂铁铜稀土矿床是滇中地区具有代表性的元古宙铁铜稀土矿床之一。矿床中除了铁、铜资源外,还伴生有稀土、稀有(铌)、钇、钼、钴等组分。研究表明:稀土元素含量在条纹条带状矿石和脉状矿石中均较高,ΣREE含量分别高达(1 446.83~11 259.23)×10-6和(2 020.92~3 415.51)×10-6,尤其富集La、Ce等轻稀土元素;稀有(铌)元素主要富集在条纹条带状矿石中,含量高达(278.8~529.0)×10-6。由于矿床的矿物组成非常复杂,并且矿石中稀土、稀有(铌)矿物含量相对较少,矿物结晶粒度细小,用传统的测试技术和方法很难识别鉴定,因此矿床的矿物学特征,尤其是稀土、稀有(铌)矿物的赋存状态特征研究一直以来都较为棘手。论文应用矿物表征自动定量分析系统(AMICS),结合扫描电镜能谱仪(SEM-EDS)显微结构原位分析技术,完成了常规岩矿鉴定手段难以完成的矿物定量识别和鉴定,在矿石中发现了含量可观的氟碳钙铈矿、氟碳铈矿和少量的独居石、褐帘石、铌铁矿、褐钇铌矿、硅钍钇矿、含铌金红石等稀有稀土矿物。其中,氟碳铈矿、独居石、铌铁矿、褐钇铌矿等主要富集于条纹条带状矿石中,与铁氧化物、磷灰石、萤石、菱铁矿和早期黄铜矿、黄铁矿等紧密共生;氟碳钙铈矿、褐帘石、硅钍钇矿、含铌金红石等主要局部富集在脉状矿石中,与石英、方解石、绿泥石和晚期黄铜矿、黄铁矿等紧密共生。显然,在铁氧化物和铜硫化物成矿两个阶段均伴随有稀土成矿作用。结合前人的研究成果,笔者将主矿化期划分为铁氧化物磷灰石稀土成矿阶段(Ⅱ-1)和铜硫化物(金)稀土成矿阶段(Ⅱ-2)。其中,氟碳铈矿、独居石、铌铁矿、褐钇铌矿等主要形成于Ⅱ-1阶段,其成矿作用可能与Columbia超大陆裂谷化裂解有关;氟碳钙铈矿、褐帘石、硅钍钇矿、(含铌)金红石等则主要形成于Ⅱ-2阶段,其成矿作用可能与Rodinia超大陆裂解有关。对比研究发现,云南武定迤纳厂铁铜稀土矿床与白云鄂博超大型铌铁稀土矿床在大地构造背景、成矿元素组合、赋矿岩系、矿物组成、成矿时代、稀土来源等方面均有可对比性,初步确定云南武定迤纳厂铁铜稀土矿床是一个“白云鄂博式”矿床。

 

关键词: &ldquo, 白云鄂博式&rdquo, 矿床;铁铜稀土矿床;稀有稀土矿物;迤纳厂;滇中;AMICS

Abstract: The Yinachang Fe-Cu-REE deposit is one of representative Proterozoic Fe-Cu-REE deposits in central Yunnan, SW China. Besides Fe and Cu, rare-earth elements (REEs, mainly La, Ce), Nb, Y, Mo and Co coexist in the deposit. Study has shown that REE contents are relatively high in both banded and vein ores ranging in (1446.8311259.23)×10-6 and (2020.923415.51)×10-6, respectively, with light REEs (e.g., La, Ce) especially enriched. Also, the content of rare element Nb reaches up to (278.8529.0)×10-6 in the banded ores. However, it has long been difficult to study mineral characteristics, especially occurrence characteristics, of rare and rare-earth minerals using traditional testing techniques, which were inadequate to identify these minerals due to complex mineral composition of ore deposit and relatively low mineral contents in ores. In this study, we used automated mineral identification and characterization system (AMICS)—the most up-to-date mineral automatic analysis system in mineralogy and geology in the world, combined with scanning electron microscope and X-ray energy dispersive spectrometer (SEM-EDS) microstructural in-situ analysis technique, to complete quantitative mineral identification in the Yinachang Fe-Cu-REE deposit, an undertaking unattainable by conventional means of rock-mineral identification. The results demonstrate that the deposit contains large quantities of parisites and bastnaesites and small quantities of monazites, allanites, columbites, fergusonites, yttrialites and Nb-bearing rutiles. Bastnaesites, monazites, columbite and fergusonite are mainly concentrated in the banded ores and closely associated with iron oxide minerals (magnetites), siderites, apatites, flourite and early sulfides such as chalcopyrite, pyrite, etc, while parisites, allanite, yttrialite and Nb-bearing rutile are enriched in vein ores coexisting mainly with chlorites, calcite, quartz and late sulfides such as chalcopyrite, pyrite, etc. Plainly, both iron oxide and copper sulfide mineralization stages are associated with REE mineralization. We identified two main mineralization stages, i.e., iron oxide-apatite-REE (Ⅱ-1) and Cu sulfides(-Au)-REE (Ⅱ-2) mineralization stages, both were apparently related to the deep (mantle) magmatic activities: bastnaesites, monazites, columbite and fergusonite primarily formed in the Ⅱ-1 stage, likely during the breakup of the Columbia supercontinent; and parisites, allanite, yttrialite and Nb-bearing rutile mainly formed in the Ⅱ-2 stage, possibly during the breakup of the Rodinia supercontinent. Through comparative studies, we found that the Yinachang Fe-Cu-REE and giant Bayan Obo Nb-Fe-REE deposits are comparable in tectonic settings, metallogenic element assembles, ore-hosting rock series, mineral compositions, ore-forming ages and material sources. Therefore, we propose, preliminarily, that the Yinachang Fe-Cu-REE deposit is a “Bayan Obo-type” deposit.

Key words: “Bayan Obo-type&rdquo, deposit, Fe-Cu-REE deposit, rare and rare-earth minerals, Yinachang, central Yunnan Province, AMICS

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