Chinese Science Bulletin

, Volume 46, Issue 3, pp 252–255 | Cite as

Nd isotopic disequilibrium between minerals and Rb-Sr age of the secondary phengite in eclogite from the Yangkou area, Qingdao, eastern China

  • Shuguang Li
  • Weidong Sun
  • Zongqing Zhang
  • Qiuli Li


There are two generations of white micas in retrograded coesite-bearing eclogite from the Yangkou area near Qingdao, eastern China. The secondary phengite developed along the folliations in eclogite is the majority of the white micas. Nd and Sr isotopic disequilibriums between garnet and retrograded omphacite as well as secondary phengite have been observed. Consequently, the Rb-Sr ages ((193 ±4) Ma-(195 ±4) Ma) given by the tie lines of the secondary phengite + garnet or whole rock may predate the formation time of the phengite. The Rb-Sr age of (183 ±4) Ma given by the secondary phengite + retrograde omphacite is much closer to the formation time of the phengite indicating the retrograde age of eclogite instead of a cooling age of eclogite at 500°C.


eclogite Nd isotopic disequilibrium Rb-Sr dating Su-Lu UHPM belt 


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Copyright information

© Science in China Press 2001

Authors and Affiliations

  • Shuguang Li
    • 1
  • Weidong Sun
    • 1
  • Zongqing Zhang
    • 2
  • Qiuli Li
    • 1
  1. 1.Chemical Geodynamics Laboratory, Department of Earth and Space SciencesUniversity of Science and Technology of ChinaHefeiChina
  2. 2.Institute of GeologyChinese Academy of Geological SciencesBeijingChina

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