Natural (Mg,Fe)SiO3-ilmenite and -perovskite in the Tenham meteorite.

Abstract

The minerals (Mg,Fe)SiO3-ilmenite and -perovskite were identified in the shock-induced veins in the Tenham chondritic meteorite. Both phases are inferred to have transformed from pyroxene at high pressures and temperatures by shock metamorphism. Columnar-shaped ilmenite grains, one of two types of morphologies, have a topotaxial relationship with neighboring pyroxene grains, indicating shear transformation. Granular-shaped perovskite grains showed a diffraction pattern consistent with orthorhombic perovskite, but these grains were not stable under the electron beam irradiation and became amorphous. The higher iron concentration in both phases compared with those experimentally reported may suggest their metastable transition from enstatite because of shock compression.

• Authors: N Tomioka, K Fujino
• Journal: Science (New York, N.Y.) (Science) Vol. 277 Issue 5329 Pg. 1084-6 (Aug 22 1997) ISSN: 0036-8075 [Print] United States
• PMID: 9262473 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Calcium Compounds
• Iron Compounds
• Magnesium Compounds
• Oxides
• Silicates
• ilmenite
• perovskite
• olivine
• Titanium
• Iron

Topics

• Calcium Compounds (analysis, chemistry)
• Iron (analysis, chemistry)
• Iron Compounds (analysis, chemistry)
• Magnesium Compounds (analysis, chemistry)
• Meteoroids
• Microscopy, Electron
• Oxides (analysis, chemistry)
• Pressure
• Silicates (analysis, chemistry)
• Temperature
• Titanium (analysis, chemistry)