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Updated: Jun 21, 2026
07:03
Low-energy Cathodoluminescence for (Oxy)Nitride Phosphors
Published on: November 15, 2016
Summary
Cosmic ray analysis of iron meteorites reveals unusually short exposure times, with some similar to chondrites. This suggests a significant portion of iron meteorites may have experienced brief cosmic ray exposure.
Area of Science:
- Cosmochemistry
- Nuclear Geophysics
- Meteoritics
Background:
- Cosmic ray exposure dating is crucial for understanding meteorite histories.
- Argon isotopes (Argon-38 and Argon-39) are commonly used cosmogenic nuclides.
- Iron meteorites typically exhibit longer cosmic ray exposure histories than chondrites.
Purpose of the Study:
- To analyze argon-38 and argon-39 concentrations in iron meteorites.
- To determine the cosmic ray exposure durations of these meteorites.
- To compare exposure times with those of other meteorite types.
Main Methods:
- Mass spectrometry was used to measure argon-38 and argon-39 isotopes.
- Analysis was performed on samples from four iron meteorites.
- Cosmogenic nuclide concentrations were used to calculate exposure ages.
Main Results:
- Normal levels of radioactive argon-39 were detected.
- Abnormally low levels of stable argon-38 were found.
- Calculated exposure times were significantly shorter than average for iron meteorites.
Conclusions:
- The iron meteorites studied were exposed to cosmic rays for unusually short periods.
- These short exposure durations overlap with those observed in chondrites.
- It is hypothesized that approximately 20% of iron meteorites may have similar short exposure histories.
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