Origin of Apollo 17 rocks and soils

Lithophile trace element abundances have been determined by mass spectrometric isotope dilution for a suite of Apollo 17 samples. The six mare basalts have generally similar relative trace element abundances; they are also similar to Apollo 11 trace element poor basalts. It is suggested that these basalts were derived by partial fusion of cumulates. The Apollo 17 highland breccias show an order of magnitude range in trace element abundances although there is a clustering of KREEP-rich samples which are interpreted as mixtures. The Apollo 17 soils show only a limited range of trace element abundances. They are mixtures of highland breccias, mare basalts, and orange-black 'soil'. There appear to be two groups of soils, Light Mantle and the rest. Both groups seem to have the same basalt component, which is similar to Station 4 basalt from Shorty Crater and probably is the uppermost basalt unit throughout the Taurus-Littrow valley.