ArticlesAbundance of Major Elements

Trapped Solar Wind Noble Gases, Kr81/Kr Exposure Ages and K/Ar Ages in Apollo 11 Lunar Material

See allHide authors and affiliations

Science  30 Jan 1970:
Vol. 167, Issue 3918, pp. 558-560
DOI: 10.1126/science.167.3918.558


Grain size and etching experiments show that the fine lunar material contains large amounts of trapped solar wind particles. Elemental and isotopic compositions of the noble gases in solar material and in the terrestrial atmosphere are significantly different, except for the Ar36/ Ar38 and the Kr isotope ratios. Exposure ages of two rocks and of the fine material are between 380 and 510 x 106 years. Feldspar concentrates give K/Ar ages of 3220 and 3300 x 106 years, significantly higher than the unseparated rock.

Stay Connected to Science