PlumX Metrics
Embed PlumX Metrics

In-situ U Pb geochronology of vesuvianite in skarn deposits

Chemical Geology, ISSN: 0009-2541, Vol: 612, Page: 121136
2022
  • 15
    Citations
  • 0
    Usage
  • 10
    Captures
  • 0
    Mentions
  • 0
    Social Media
Metric Options:   Counts1 Year3 Year

Metrics Details

Article Description

The timing of hydrothermal activity is a key factor in any predictive genetic model of skarn mineralization, but direct dating is often hindered by the absence of suitable minerals to date. Vesuvianite, a common mineral in skarn deposits, can incorporate U and has a high Pb closure temperature (>650 °C), and consequently may be suitable for dating for skarn deposits. Vesuvianite collected from nine Chinese skarn deposits, including the Jinchuantang Sn Bi, Shizhuyuan W–Sn–Mo–Bi polymetallic, Jiepai Cu W, Dashunlong Sn, Xianghualing Sn, Furong Sn, and Huangshaping W–Sn–Mo–Cu polymetallic deposits in Nanling Range (Southern China), and the Kaerqueka and Saishitang Cu deposits in East Kunlun Orogen (Northwestern China), have high U concentrations (median 66.8 ppm for 460 LA-ICP-MS analysis spots). The flat and stable time-resolved signal spectra for U during LA-ICP-MS analysis, combined with the absence of nanoscale mineral inclusions, porosities, or lattice defects in the JCT vesuvianite, with high and consistent U concentrations, revealed by the HAADF-STEM images, and the marked positive relationships between U and REE collectively suggest that the U incorporation into vesuvianite was primarily controlled by replacement of Ca 2+ in eight-fold coordination, confirming that vesuvianite may be a suitable U Pb geochronometer. The JCT vesuvianite is characterized by high and consistent U concentrations (260–526 ppm, median 307 ppm) and homogeneous internal texture and elemental distribution, and yields an ID-TIMS U Pb concordia age (2σ, 153.9 ± 0.2 Ma, MSWD = 1.6, n  = 11), demonstrating that it can be taken as a potential LA-ICP-MS U Pb reference material, which can be freely distributed to other laboratories. Using the JCT vesuvianite as a U Pb reference material, the Kaerqueka, Saishitang, Jiepai, Dashunlong, Xianghualing, Furong, and Shizhuyuan vesuvianite yielded well-defined LA-ICP-MS U Pb ages (239.0–152.1 Ma, 2σ), consistent with previously published age constraints of mineralization and cogenetic igneous rocks. Vesuvianite from the Huangshaping W–Sn–Mo–Cu polymetallic deposit, yielded U Pb ages of 157.3 ± 1.4 Ma (2σ, MSWD = 1.8) and 161.0 ± 1.3 Ma (2σ, MSWD = 1.9), providing reliable constraints on the overprinting sequence of the skarn W–Sn–Mo and Cu mineralization events at Huangshaping, which was not previously detectable using other mineralization chronometers. Combined, these ages suggest that vesuvianite is a robust and reliable geochronometer, and offers a new tool for dating skarn deposits.

Bibliographic Details

Yu Zhang; Shuling Song; Pete Hollings; Dengfeng Li; Yongjun Shao; Huayong Chen; Lianjie Zhao; Sandra Kamo; Tingting Jin; Lingling Yuan; Qingquan Liu; Shaocong Chen

Elsevier BV

Earth and Planetary Sciences

Provide Feedback

Have ideas for a new metric? Would you like to see something else here?Let us know