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Fluid flow on centimeter-scale in deep paleosubduction zones in western Tianshan, China: Evidence from high-pressure veins

  • Jin-fu Zhang (张进富)Email author
  • De-zhi Huang (黄德志)
  • Shi-qi Huang (黄始琪)
  • Guo-ming Li (李国明)
  • Jun Gao (高俊)
  • Yong-hong Shi (石永红)
Article

Abstract

High-pressure(HP) veins were extensively developed in western Tianshan high-pressure(HP) metamorphic belt. The HP vein and host-rocks were analyzed by electronic microprobe to trace the origin of vein-forming fluids. Analytical data show that the immediately adjacent host-rocks of the studied HP vein are eclogites and gradually turned into blueschist as the distance from the veins increases, which indicates that the vein-forming fluid was derived from adjacent host-rocks; the boundaries between the vein and the host-rocks are sharp, which indicates that the fracture of the host-rocks is brittle during the vein-forming process. It is suggested that this type of HP veins is precipitated from the liquid formed by the dehydration of the host-rocks during the prograde metamorphism from blueschist to eclogite facies, which results in hydrofracturing of the rocks and provides the space for the vein to precipitate. The width of the eclogite-facies host-rocks is usually 1–2 cm, which provides the direct evidence that the fluid flow is on centimeter-scale.

Key words

subduction zone high-pressure vein scale of fluid flow western Tianshan 

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Copyright information

© Central South University Press and Springer-Verlag GmbH 2008

Authors and Affiliations

  • Jin-fu Zhang (张进富)
    • 1
    Email author
  • De-zhi Huang (黄德志)
    • 1
  • Shi-qi Huang (黄始琪)
    • 1
  • Guo-ming Li (李国明)
    • 1
  • Jun Gao (高俊)
    • 2
  • Yong-hong Shi (石永红)
    • 3
  1. 1.School of Geosciences and Environmental EngineeringCentral South UniversityChangshaChina
  2. 2.Chinese Academy of SciencesBeijingChina
  3. 3.School of Resources and Environmental EngineeringHefei University of TechnologyHefeiChina

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