准苏吉花斑岩型钼铜矿床岩体特征及成矿机制研究

doi:10.13209/j.0479-8023.2020.031

北京大学学报自然科学版 ›› 2020, Vol. 56 ›› Issue (4): 679-691.DOI: 10.13209/j.0479-8023.2020.031

准苏吉花斑岩型钼铜矿床岩体特征及成矿机制研究

刘聪, 郭虎, 赖勇^†

造山带与地壳演化教育部重点实验室, 北京大学地球与空间科学学院, 北京 100871

收稿日期:2019-05-10 修回日期:2020-04-12 出版日期:2020-07-20 发布日期:2020-07-20
通讯作者: 赖勇, E-mail: yonglai(at)pku.edu.cn
基金资助:
国家重点研发计划(2017YFC0601302)资助

Study on Granitoid Intrusions Characteristics and Metallogenetic Mechanism of Zhunsujihua Porphyry Mo-Cu Deposit

LIU Cong, GUO Hu, LAI Yong^†

Key Laboratory of Orogenic Belts and Crustal Evolution (MOE), School of Earth and Space Sciences, Peking University, Beijing 100871

Received:2019-05-10 Revised:2020-04-12 Online:2020-07-20 Published:2020-07-20
Contact: LAI Yong, E-mail: yonglai(at)pku.edu.cn

摘要/Abstract

摘要：

通过对辉钼矿的Re-Os及锆石U-Pb同位素年代学研究, 得到辉钼矿的Re-Os等时线年龄为297.2±4.3 Ma, 赋矿花岗斑岩的锆石U-Pb年龄为 301.1±4.0 Ma, 确定准苏吉花斑岩型钼铜(Mo-Cu)矿床的成岩成矿时代为晚石炭世至早二叠世。准苏吉花矿区不含矿花岗闪长岩的锆石U-Pb 年龄为301.2±2.2 Ma, 与花岗斑岩成岩时代一致。发育角闪石和黑云母的矿物学特征以及高Rb, Th和Ba, 低P和Ti的岩石地球化学特征表明, 花岗斑岩和花岗闪长岩同属于I型花岗岩。较低的Re含量、Mg#值、Nb/Ta值和Zr/Hf值以及低ISr值和正ε_Nd(t)值的全岩Sr-Nd同位素特征表明, 准苏吉花花岗岩的源区为新生下地壳的部分熔融, 岩浆演化过程中, 花岗斑岩和花岗闪长岩均经历较强烈的分离结晶作用, 有利于Mo进一步在残余熔体中富集。通过锆石的Ce⁴⁺/Ce³⁺值计算获得岩浆结晶分异时的氧逸度, 发现花岗斑岩岩浆的氧逸度相对较高(ΔFMQ平均值为+4.8), 花岗闪长岩岩浆氧逸度相对较低(ΔFMQ平均值为+2.2), 表明高氧逸度的岩浆更有利于Mo和Cu富集成矿。

关键词: 斑岩型钼铜矿床, 锆石U-Pb年代学, 辉钼矿Re-Os定年, I型花岗岩, 氧逸度, 准苏吉花

Abstract:

A precise Re-Os isochron age of 297.2±4.3 Ma for the molybdenite and a zircon U-Pb age of 301.1±4.0 Ma for the ore-bearing granite porphyry determined that the age of diagenesis and mineralization of Zhunsujihua porphyry Mo-Cu Deposit is from Late Carboniferous to Early Permian. The barren granodiorite in this mining area yielded a zircon U-Pb age of 301.2±2.2 Ma, which is consistent with that of granite porphyry. Amphibole and biotite in granitic rocks and their geochemical characteristics of high Rb, Th, Ba, and low P, Ti suggest that granite porphyry and granodiorite belong to I-type granites. Relatively low Re, Mg#, Nb/Ta, Zr/Hf values, coupled with whole-rock Sr-Nd isotopes (low ISr and positive ε_Nd(t)) signify that they are mainly originated from a juvenile lower crust source derived from depleted mantle. It can be recognized from the whole-rock major and trace element data that significant fractional crystallization occurs during magmatic evolution, which is beneficial to further enrichment of Mo in the melt. Using the Ce⁴⁺/Ce³⁺ ratio in zircons to calculate the oxygen fugacity of magma during fractionation, it is found that the oxygen fugacity of granite porphyry is relatively high (average ΔFMQ is +4.8), and that of the granodiorite is relatively low (average ΔFMQ is +2.2), indicating that magma with high oxygen fugacity is more conducive to mineralization.

Key words: porphyry Mo-Cu deposit, zircon U-Pb dating, molybdenite Re-Os dating, I-type granite, oxygen fugacity, Zhunsujihua

刘聪, 郭虎, 赖勇. 准苏吉花斑岩型钼铜矿床岩体特征及成矿机制研究[J]. 北京大学学报自然科学版, 2020, 56(4): 679-691.

LIU Cong, GUO Hu, LAI Yong. Study on Granitoid Intrusions Characteristics and Metallogenetic Mechanism of Zhunsujihua Porphyry Mo-Cu Deposit[J]. Acta Scientiarum Naturalium Universitatis Pekinensis, 2020, 56(4): 679-691.

导出引用管理器 EndNote|Ris|BibTeX

链接本文: https://xbna.pku.edu.cn/CN/10.13209/j.0479-8023.2020.031

https://xbna.pku.edu.cn/CN/Y2020/V56/I4/679

[1]	庞菲, 李秋根, 刘树文, 王宗起, 柳政甫, 梅可辰. 吕梁地区宁家湾岩体锆石U-Pb年代学、地球化学特征及地质意义[J]. 北京大学学报自然科学版, 2019, 55(1): 133-147.
[2]	郭丽爽, 吕鑫, 王政华, 毛佐国, 张继林, 刘玉琳, 陈旭. 广西大宁岩体和初洞岩体锆石U-Pb年代学及Hf同位素研究[J]. 北京大学学报自然科学版, 2017, 53(4): 667-682.
[3]	上官时迈, 田伟,李献华, 关平, 潘懋, 陈咪咪, 潘文庆. 塔北哈拉哈塘流纹岩的离子探针锆石U-Pb 年代学: 对塔里木溢流玄武岩主期喷发时代的约束[J]. 北京大学学报（自然科学版）, 2011, 47(3): 561-564.
[4]	凤永刚,刘树文,吕勇军,田伟,柳小明. 冀北凤山晚古生代闪长岩-花岗质岩石的成因：岩石地球化学、锆石U-Pb年代学及Hf同位素制约[J]. 北京大学学报（自然科学版）, 2009, 45(1): 59-70.

准苏吉花斑岩型钼铜矿床岩体特征及成矿机制研究

Study on Granitoid Intrusions Characteristics and Metallogenetic Mechanism of Zhunsujihua Porphyry Mo-Cu Deposit

PDF

可视化

摘要/Abstract

引用本文

使用本文

参考文献

相关文章 4

编辑推荐

Metrics

留言