In Situ Analyses of Trace Elements, U–Pb and Lu–Hf Isotopes in Zircons from the Tongshankou Granodiorite Porphyry in Southeast Hubei Province, Middle-Lower Yangtze River Metallogenic Belt, China
基金项目:

This work was supported by geological survey projects of the China Geological Survey (1212011120863,12120114039401, 12120114005901 and 12120115029401).


In Situ Analyses of Trace Elements, U–Pb and Lu–Hf Isotopes in Zircons from the Tongshankou Granodiorite Porphyry in Southeast Hubei Province, Middle-Lower Yangtze River Metallogenic Belt, China
Author:
Fund Project:

This work was supported by geological survey projects of the China Geological Survey (1212011120863,12120114039401, 12120114005901 and 12120115029401).

  • 摘要
  • | |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • | |
  • 文章评论
    摘要:

    The Tongshankou Cu-Mo deposit, located in southeast Hubei province, is a typical skarn–porphyry type ore deposit closely related to the Tongshankou granodiorite porphyry, characterized by a high Sr/Y ratio. Detailed in situ analyses of the trace elements and U–Pb and Lu–Hf isotopes in zircons from the Tongshankou granodiorite porphyry were performed. Scarcely any inherited zircons were observed, and the analyzed zircons yielded highly concordant results with a weighted mean 206Pb/238U age of 143.5 ± 0.45 Ma (n=20, mean square weighted deviation was 0.75), which was interpreted to represent the crystallization age of the Tongshankou granodiorite porphyry. The chondrite-normalized rare-earth element pattern was characterized by a slope that steeply rises from the light-group rare-earth elements (LREE) to the heavy-group rare-earth elements (HREE) with a positive Ce-anomaly and inconspicuous Eu-anomaly, which was coincident with the pattern of the zircons from the Chuquicamata West porphyry, Chile. The analyzed zircons also had relatively low 176Hf/177Hf ratios of 0.282526–0.282604. Assuming t=143 Ma, the corresponding calculated initial Hf isotope compositions (εHf(t)) ranged from ?5.6 to ?2.9. The results of the in situ analysis of trace elements and U–Pb and Lu–Hf isotopes in zircons from the Tongshankou granodiorite porphyry suggest that a deep-seated process involving a thickened-crust/enriched-mantle interaction may play an important role in the generation of high Sr/Y-ratio magma and potentially in the generation of porphyry Cu-Mo systems.

    Abstract:

    The Tongshankou Cu-Mo deposit, located in southeast Hubei province, is a typical skarn–porphyry type ore deposit closely related to the Tongshankou granodiorite porphyry, characterized by a high Sr/Y ratio. Detailed in situ analyses of the trace elements and U–Pb and Lu–Hf isotopes in zircons from the Tongshankou granodiorite porphyry were performed. Scarcely any inherited zircons were observed, and the analyzed zircons yielded highly concordant results with a weighted mean 206Pb/238U age of 143.5 ± 0.45 Ma (n=20, mean square weighted deviation was 0.75), which was interpreted to represent the crystallization age of the Tongshankou granodiorite porphyry. The chondrite-normalized rare-earth element pattern was characterized by a slope that steeply rises from the light-group rare-earth elements (LREE) to the heavy-group rare-earth elements (HREE) with a positive Ce-anomaly and inconspicuous Eu-anomaly, which was coincident with the pattern of the zircons from the Chuquicamata West porphyry, Chile. The analyzed zircons also had relatively low 176Hf/177Hf ratios of 0.282526–0.282604. Assuming t=143 Ma, the corresponding calculated initial Hf isotope compositions (εHf(t)) ranged from ?5.6 to ?2.9. The results of the in situ analysis of trace elements and U–Pb and Lu–Hf isotopes in zircons from the Tongshankou granodiorite porphyry suggest that a deep-seated process involving a thickened-crust/enriched-mantle interaction may play an important role in the generation of high Sr/Y-ratio magma and potentially in the generation of porphyry Cu-Mo systems.

    参考文献
    相似文献
    引证文献
引用本文

XIA Jinlong, HUANG Guicheng, DING Lixue, CHENG Shunbo.2015. In Situ Analyses of Trace Elements, U–Pb and Lu–Hf Isotopes in Zircons from the Tongshankou Granodiorite Porphyry in Southeast Hubei Province, Middle-Lower Yangtze River Metallogenic Belt, China[J]. ACTA GEOLOGICA SINICA(English edition),89(5):1588~1600

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:2014-03-26
  • 最后修改日期:2014-11-15
  • 在线发布日期: 2015-10-15
文章二维码