COSMIC RADIATION AND THE K$sup 40$-A$sup 40$ "AGES" OF IRON METEORITES
The potassium-- argon data of Stoenner and Zachringer are consistent with an age for the iron meteorites of 5.0 plus or minus 0.5 aeons. For iron meteorites with moderate to high concentrations of He-3, the Ar/sup 40/ which has been produced by nuclear spallation and the Ar/sup 40/ produced by the decay of primordial K-40 can be calculated accurately (provided that the radiation age of the meteorite is known) and their sum compared to the measured Ar/sup 10/. Cosmogenic neon and argon predominate in inclusions of troilite and schreibersite in large ion meteorites. The enhanced yield of these elements seems to be due to the interaction of cosmic rays with elements below iron in atonaic mass, such as chlorine, sulfur, and phosphorus. The K-39/K-41 ratio of some potassium recovered from the Canyon Diablo iron meteorite differed by less than 2% from the ratio in terrestrial potassium, but was consistent with the low radiation age of 0.145 aeon calculated by Fisher and Schaeffer for this meteorite, (auth)
- Research Organization:
- California Inst. of Tech., Pasadena. Jet Propulsion Lab.
- NSA Number:
- NSA-16-025614
- OSTI ID:
- 4818362
- Report Number(s):
- JPL-TR-32-147; AD-271649
- Country of Publication:
- United States
- Language:
- English
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