Rb-Sr studies of lunar breccias and soils

Abstract

Investigation results on the Rb-Sr systematics and K concentrations for two Apollo 14 breccias and several Apollo 15, 16, and 17 soils are reviewed. The reported results include the finding that plagioclase clasts from microbreccia fragments in Apollo 16 soil are distinctly too radiogenic to have been in equilibrium with the whole rock fragments 4 b.y. ago.