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Fission track astrology of three Apollo 14 gas-rich brecciasThe three Apollo 14 breccias 14301, 14313, and 14318 all show fission xenon due to the decay of Pu-244. To investigate possible in situ production of the fission gas, an analysis was made of the U-distribution in these three breccias. The major amount of the U lies in glass clasts and in matrix material and no more than 25% occurs in distinct high-U minerals. The U-distribution of each breccia is discussed in detail. Whitlockite grains in breccias 14301 and 14318 found with the U-mapping were etched and analyzed for fission tracks. The excess track densities are much smaller than indicated by the Xe-excess. Because of a preirradiation history documented by very high track densities in feldspar grains, however, it is impossible to attribute the excess tracks to the decay of Pu-244. A modified track method has been developed for measuring average U-concentrations in samples containing a heterogeneous distribution of U in the form of small high-U minerals. The method is briefly discussed, and results for the rocks 14301, 14313, 14318, 68815, 15595, and the soil 64421 are given.
Document ID
19740040196
Document Type
Conference Proceedings
Authors
Graf, H.
Shirck, J.
Sun, S.
Walker, R. (Washington University St. Louis, Mo., United States)
Date Acquired
August 7, 2013
Publication Date
January 1, 1973
Subject Category
SPACE SCIENCES
Meeting Information
Lunar Science Conference(Houston, TX)
Funding Number(s)
CONTRACT_GRANT: NGL-26-008-065
Distribution Limits
Public
Copyright
Other