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Shock-produced olivine glass: first observation
Science (New York, N.Y.)
|July 29, 1977
Summary
Shock deformation of peridot at high pressures (56 GPa) created the first observed olivine glass. This discovery suggests shock events above 50-55 GPa can form glass in natural olivines.
Area of Science:
- Geology
- Materials Science
- Mineral Physics
Background:
- Peridot, a gem-quality variety of the mineral olivine, is a major component of Earth's upper mantle.
- Understanding the behavior of olivine under extreme conditions is crucial for planetary science and geophysics.
Purpose of the Study:
- To investigate the microstructural changes in natural peridot subjected to experimental shock deformation.
- To identify the formation conditions and characteristics of any amorphous phases produced by shock.
Main Methods:
- Transmission electron microscopy (TEM) was used to examine a single crystal of natural peridot.
- The peridot sample was experimentally shock-deformed to a peak pressure of approximately 56 GPa.
Main Results:
- Amorphous zones, identified as olivine glass, were observed within crystalline regions of the shocked peridot.
- The glass formation was closely associated with areas exhibiting a high density of tangled dislocations.
- The study provides the first reported observation of shock-induced olivine glass.
Conclusions:
- Olivine glass may form in natural olivines subjected to shock pressures exceeding approximately 50-55 GPa.
- Further TEM studies of naturally shocked olivines could confirm the widespread presence of shock-induced glass.
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