P. K. Kuroda

Iodine, uranium and tellurium contents in meteorites

Abstract The abundances of iodine, uranium and tellurium were determined in fifteen achondrites, five chondrites (two with light-dark structure) and three mesosiderites by neutron activation analysis. In thirty analyses on achondrites we found the following range of abundances: I, 14 ppb-1 ppm; U, 2–210 ppb and Te, ≤0.03-3 ppm. These elements vary within a given class of achondrites and the individual achondrites show a higher degree of heterogeneity than the chondrites. The iodine content of achondrites is of the same order as in chondrites. Uranium contents range higher and tellurium lower in achondrites than in chondrites. Weaker correlation between iodine and tellurium is observed in achondrites than in chondrites.

Excess Xenon-128 in meteorites

Using known compositions of primordial and spallation xenon components in several meteorites, the neutron produced Xe128n has been resolved. For obtaining the value for spallation produced (Xe128/Xe130)c, the meteorites with low iodine content and high spallation contribution are considered. Using these data, the neutron densities in several meteorites due to cosmic-ray exposure are calculated and their significance is qualitatively discussed.