The thermal and radiation exposure history of lunar meteorites

by Benoit, P. H.; Sears, D. W. G.; Symes, S. J. K.

We have measured the natural and induced thermoluminescence (TL) of seven lunar meteorites in order to examine their crystallization, irradiation, and recent thermal histories. Lunar meteorites have induced TL properties similar to Apollo samples of the same provenance (highland or mare), indicating similar crystallization and metamorphic histories. MacAlpine Hills 88104/5 has experienced the greatest degree of impact/regolith processing among the highland-dominated meteorites. The basaltic breccia QUE 94281 is dominated by mare component but may also contain a significant highland component. For the mare-dominated meteorites, EET 87521 may have a significant highland impact-melt component, while Asuka 881757 and Y-793169 have been heavily shocked. The thermal history of Y-793169 included slow cooling, either during impact processing or during its initial crystallization. Our natural TL data indicate that most lunar meteorites have apparently been irradiated in space a few thousand years, with most < 15,000 a. Elephant Moraine 87521 has the lowest irradiation exposure time, being < 1,000 a. Either the natural TL of ALHA81005, Asuka 881757 and Y-82192 was only partially reset by lunar ejection or these meteorites were in small perihelia orbits (less than or equal to 0.7 AU).

Journal
Meteoritics and Planetary Science
Volume
31
Issue
6
Year
1996
Start Page
869-875
URL
https://dx.doi.org/10.1111/j.1945-5100.1996.tb02120.x
ISBN/ISSN
1945-5100; 1086-9379
DOI
10.1111/j.1945-5100.1996.tb02120.x