MAJOR COMPOSITIONAL UNITS OF THE MOON - LUNAR PROSPECTOR THERMAL AND FAST-NEUTRONS

Global maps of thermal and fast neutron fluxes from the moon suggest t hree end-member compositional units. A high thermal and Low fast neutr on flux unit correlates with the Lunar highlands and is consistent wit h feldspathic rocks. The South Pole-Aitken basin and a strip that surr ounds the nearside maria have intermediate thermal and fast neutron fl ux Levels, consistent with more mafic rocks. There appears to be a smo oth transition between the most mafic and feldspathic compositions, wh ich correspond to Low and high surface altitudes, respectively. The ma ria show Low thermal and high fast neutron fluxes, consistent with bas altic rocks.