辽宁后仙峪硼矿区混合岩的LA-MC-ICP-MS锆石U-Pb年龄:对硼矿成矿演化的制约
DOI:
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

本文为国土资源部公益性行业科研专项经费项目(编号: 2012110742 20091104320);中国地质调查局二级项目(编号:DD20160040)的成果。


LA-MCICP-MS U-Pb Zircon Ages of Paleoproterozoic Migmatitized Granites from the Houxianyu Borate Deposit, Eastern Liaoning:Constraints on the Evolution of the Borate Deposits
Author:
Affiliation:

Fund Project:

单位:
  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    辽东硼矿赋存于辽吉裂谷带的古元古代火山—沉积岩系之中,属沉积—变质型硼矿床,主矿区包括有后仙峪硼镁矿、翁泉沟硼铁矿和砖庙—杨木杆硼镁矿,一直以来是我国硼矿石的主产地。本次研究在后仙峪硼矿区采集了矿区外围的条痕状混合花岗岩(DSQ08)和矿体上盘侵位于电英岩之中的含电气石混合花岗岩(HXY19),挑选出其中的锆石单矿物进行LAMCICPMS测年。条痕状混合花岗岩中锆石的核部具有岩浆振荡环带,Th/U值为064~096,207Pb/206Pb年龄为2240±4Ma;含电气石混合花岗岩中锆石的内核和边部均具有极为清晰的岩浆振荡环带,Th/U比值分别为012~105和041~108,207Pb/206Pb年龄分别记录了2157±6Ma和1932±26Ma两次锆石生长事件。含电气石的混合花岗岩的锆石边部形成于混合岩化过程之中,记录了辽河群下部岩石在19Ga左右发生的部分熔融作用事件,具有重要的地质意义。矿区外围的条痕状混合花岗岩和矿体周缘含电气石混合花岗岩的核部岩浆年龄较为接近,说明两种岩石可能均由古元古代的火山—沉积岩,在19Ga左右经部分熔融作用形成。因此,结合前人在后仙峪硼矿区内进行的硼同位素地球化学和岩相学方面的研究成果,我们认为后仙峪硼矿区混合花岗岩的锆石核部UPb年龄可基本确定辽吉裂谷早期的超基性火山岩和酸性火山岩的喷发、海相蒸发沉积事件均发生于2240~2157Ma左右,该时期的蒸发沉积作用初步形成硼酸盐矿;后期强烈的部分熔融和混合岩化作用发生在1932±26Ma,在超基性火山岩保护下,硼矿发生变质和小规模的迁移,形成了硼镁矿、硼镁铁矿及矿体周缘的电英岩和含电气石混合花岗岩。

    Abstract:

    The Eastern Liaoning sedimento—metamorphic borate deposits located in the Paleoproterozoic volcanic—sedimentary rock series of Liaoning—Jining rift zone includes the Houxianyu boron—magnesite deposit, Wengquangou boron—iron deposit and Zhuanmiao—Yangmugan boron—magnesium deposit. It has been the main origin of boron in China. In this study, we have collected zircon for LAMCICPMS dating from the stripelike granite(DSQ08)and the tourmalinebearing leucogranite(HXY19)in the Houxianyu borate deposit. Zircons from the stripelike granite have a magmatic oscillatory zoning with a Th / U ratio of 0.64~0.96 and a 207Pb / 206Pb age of 2240 ± 4Ma. Zircons from the tourmalinebearing leucogranite also has a clear magmatic oscillation zoning and have a Th / U ratio of 0.12 ~ 1.05 in the core and 0.41 ~ 1.08 in the edge respectively, in addition, thier corresponding 207Pb / 206Pb ages recorded 2157 ± 6Ma and 1932 ± 26Ma two growth events. The zircon edge of the tourmalinebearing leucogranite is formed in the process of migmatitization, which records the partial melting event occurring in the lower part of the Liaohe Group at about 1.9 Ga, which is of great geological significance. The magmatic age of the stripelike granites and the core age of the tourmalinebearing leucogranite in the periphery of the orebodies are close to each other, indicating that the two rocks may be derived from partial melting of Paleoproterozoic volcanic—sedimentary rocks at about 1.9 Ga. Therefore, in combination with previous studies on boron isotopic geochemistry and petrography in the Houxianyu borate deposit, we believe that the zircon core UPb age in the leucogranite of the Houxianyu borate deposit can be basically determined the eruption of the ultramafic volcanic rocks and acid volcanic rocks at the early stage of the rift occurred in 2240 ~ 2157Ma, and the vapor deposition in this period formed the borate deposit initially. In the latter stage, strong partial melting and migmatitization occurred in 1932 ± 26Ma, and under the protection of ultramafic volcanic rocks, the borate deposit formed by boron mineralization and smallscale migration.

    参考文献
    相似文献
    引证文献
引用本文

付燕刚,胡古月,李延河,范昌福,侯可军,赵悦.2018.辽宁后仙峪硼矿区混合岩的LA-MC-ICP-MS锆石U-Pb年龄:对硼矿成矿演化的制约[J].地质论评,64(2):405-417,[DOI].
FU Yangang, HU Guyue, LI Yanhe, FAN Chanfu, HOU Kejun, ZHAO Yue.2018. LA-MCICP-MS U-Pb Zircon Ages of Paleoproterozoic Migmatitized Granites from the Houxianyu Borate Deposit, Eastern Liaoning:Constraints on the Evolution of the Borate Deposits[J]. Geological Review,64(2):405-417.

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:
  • 最后修改日期:
  • 录用日期:
  • 在线发布日期: 2018-03-24
  • 出版日期: