Cooling rates in the shock veins of chondrites: Constraints on the (Mg, Fe)2SiO4 polymorph transformations

Ming Chen, Xiande Xie, A. El Goresy, B. Wopenka, Thomas Sharp

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

The occurrence of γ-phase, a high-pressure polymorph of olivine (α-phase), in the shock veins of Sixiangkou chondrite was due to a greater cooling rate ( > 10 000°C ·-1) in the veins. Because γ-phase partially reverted to β-phase and no back-transformation from β-phase to α-phase took place, the shock veins of Peace River chondrite with a cooling rate of 1 000 - 2 000°C · s-1 contain a great amount of β-phase. In the shock veins of Mbale chondrite with a cooling rate of <500°C · s-1, the majority of γ-phase reverted to α-phase. The heat dissipation in shock veins took place after a stage of shock compression of chondrite parent body, and the parent body was broken into fragmental pieces. Cooling rate in the shock veins constrained the back-transformations of (Mg, Fe)2SiO4 high-pressure polymorphs.

Original languageEnglish (US)
Pages (from-to)522-528
Number of pages7
JournalScience in China, Series D: Earth Sciences
Volume41
Issue number5
StatePublished - Jan 1 1998

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Keywords

  • (Mg, Fe)SiO
  • Chondrite
  • Cooling rate
  • Polymorph transformation
  • Shock vein

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

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