地质科技通报 (Sep 2021)

Diagenetic and metallogenic ages, and geological significance of the Fujiashan skarn-type(Cu-) W Deposit, southeastern Hubei Province

  • Quan Liu,
  • Yanjun Li,
  • Heng'an Cai,
  • Hongmei Li,
  • Xiaohua Zeng,
  • Xiaofeng Sun,
  • Dongqin Liu,
  • Jun Tan

DOI
https://doi.org/10.19509/j.cnki.dzkq.2021.0042
Journal volume & issue
Vol. 40, no. 5
pp. 210 – 222

Abstract

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The Fujiashan(Cu-) W Deposit, which is discovered recently, is one of the typical skarn deposit in southeastern Hubei.The(Cu-) W mineralization is closely associated with the Fujiashan granodiorite porphyry.In order to accurately determine the diagenetic and metallogenic ages of the deposit, ages of the granodiorite porphyry and (Cu-) W mineralization are studied by using LA-ICP-MS zircon U-Pb and molybdenite Re-Os isotopic dating in this paper. In addition, the tectonic setting of diagenesis and mineralization is discussed based on the sedimentary strata, structural deformation, geophysical and geochemical evidences in the middle and lower reaches of the Yangtze River during the Late Mesozoic.The results show that the granodiorite porphyry yields a weighted average 206Pb/238U age of (144±3) Ma, whereas a Re-Os model age of molybdenite of (146±2) Ma is obtained for mineralization.These isotopic ages indicate that the granodiorite porphyry and(Cu-) W mineralization at Fujiashan both formed during Late Jurassic-Early Cretaceous.In addition, the diagenesis and mineralization ages of the Fujiashan(Cu-) W Deposit are also consistent with the time of large-scale magmatic and metallogenic events for skarn Fe-Cu-Au-Mo deposits in the middle and lower reaches of the Yangtze River.According to the history of tectonic evolution and the latest chronological data in the middle and lower reaches of the Yangtze River, including southeastern Hubei, it is considered that the Fujiashan(Cu-) W Deposit is likely to be formed in a tectonic setting of lithospheric extension and thinning.The discovery and determination of Late Jurassic-Early Cretaceous skarn(Cu-) W Deposits including the Fujiashan indicate that the ore concentration area in southeastern Hubei has a good explorational prospect for tungsten deposits.

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