Pressure-induced Phase Transition and Residual Stress Studies on a Meteorite Fall at Nathdwara, India

  • Usha Chandra University of Rajasthan,Jaipur 302004
  • V. Srihari Bhabha Atomic Research Centre, Trombay , Mumbai 400085
  • K.K. Pandey Bhabha Atomic Research Centre, Trombay, Mumbai 400085
  • G. Parthasarathy CSIR, National Geophysical Research Institute, Hyderabad 500007
Keywords: Meteorites, High-Pressure, Mössbauer Spectroscopy, Synchrotron Radiation, X-ray Diffraction, Diamond Anvil Cell, Ringwoodite.


We report high pressure 57Fe Mössbauer spectroscopic (up to 10 GPa) and synchrotron X-ray diffraction (up to 16 GPa) measurements on H 6 chondrite composed predominantly of olivine, pyroxene, troilite to evaluate phase transitions and residual stresses  in the respective minerals. Mössbauer spectroscopic studies demonstrated different effect of pressure on the minerals- while troilite represented irreversible transformation from high spin magnetic to low spin paramagnetic phase at low pressure of 4.5 GPa, a displacive rearrangement of the atoms in various lattice sites was observed at ~ 6 GPa for pyroxene through sudden decrease in isomer shift. The behavior of olivine varied with the experimental conditions- it showed incomplete transformation to wadsleyite at 14.46 GPa under hydrostatic condition and complete transformation to ringwoodite at 16.72 GPa under nonhydrostatic compression. These transformations were quenchable on decompression to ambient condition indicating insufficient pressure impact on the system. In account of phase-transition-pressure on the minerals, it was concluded that the residual stress experienced by the minerals due to shock impact decreases in the order of troilite > orthopyroxene>olivine.

Author Biography

Usha Chandra, University of Rajasthan,Jaipur 302004

Professor ( Retd), Emeritus Fellow (UGC).

M.Sc. Ph.D.

Specialization: Mossbauer spectroscopy, X-ray spectroscopy, High Pressure Physics


List of Reviewers:
1. Prof. N.N. Bhandari
Physical Research Laboratory, Navrangpura, Ahmedabad 380009
Email: Mob: 9824077890

2. Dr. V.Ganesan
Centre Director UGC/DAE/CSR, Univ. Campus , Khandawa Road, Indore 452017
Email: Mob: 9893342597

3. Dr Neeta Dilawar
Pressure and Vaccum standards, National Physical Laboratory, Pusa Road,New Delhi 110012
Email: Mob: 9868122259

4. Dr Neeraj Srivastava
Physical Research Laboratory, Navrangpura, Ahmedabad 380009
Email: Phone: 079-2631-4416
Research Papers