Rare gas analysis of Apollo 11 glassy fragments
Allen, Sharon Cornelius
Master of Science
The He, Ne, and. Ar contents of nineteen Apollo-11 glasses and four Apollo-12 glasses were measured massspectrometrically. The glasses were variously colored particles: amber, clear, green, and brown, and were approximately 500 microns in size. We have found that these glassy fragments contain much smaller quantities of trapped gas (solar wind) than lithic fragments the same size. The color of the glass particles is indicative of their chemical composition. The elemental and isotopic ratios are similar to those for lunar bulk soil. It has been shown that the amber and green glasses, and possibly the brown glasses, contain a cosmogenic component of Ne21 which can be attributed to solar cosmic ray interactions with Mg24 and probably with Al27. Similarly, the clear glasses contain a cosmogenic component of Ar38 which can be attributed to solar cosmic ray interactions with Ca40. The Ne21radiation ages of three green glasses and one amber glass are older than the average Ne21 radiation age for bulk soil. Three clear glasses show an38 radiation age older than the average Ar38 radiation age for the bulk soil.