title: Apollo 16 Geochemical X-ray Fluorescence Experiment: Preliminary Report.
abstract: The lunar surface was mapped with respect to magnesium, aluminum, and silicon as aluminum/ silicon and magnesium/ silicon intensity ratios along the projected ground tracks swept out by the orbiting Apollo 16 spacecraft. The results confirm the observations made during the Apollo 15 flight and provide new data for a number of features not covered before. The data are consistent with the idea that the moon has a widespread differentiated crust (the highlands). The aluminum/ silicon and magnesium/ silicon concentration ratios correspond to those for anorthositic gabbros through gabbroic anorthosites or feldspathic basalts. The x-ray results suggest the occurrence of this premare crust or material similar to it at the Descartes landing site.
authors.forename: I
authors.initials: I
authors.lastname: Adler
authors.forename: J
authors.initials: J
authors.lastname: Trombka
authors.forename: J
authors.initials: J
authors.lastname: Gerard
authors.forename: P
authors.initials: P
authors.lastname: Lowman
authors.forename: R
authors.initials: R
authors.lastname: Schmadebeck
authors.forename: H
authors.initials: H
authors.lastname: Blodget
authors.forename: E
authors.initials: E
authors.lastname: Eller
authors.forename: L
authors.initials: L
authors.lastname: Yin
authors.forename: R
authors.initials: R
authors.lastname: Lamothe
authors.forename: G
authors.initials: G
authors.lastname: Osswald
authors.forename: P
authors.initials: P
authors.lastname: Gorenstein
authors.forename: P
authors.initials: P
authors.lastname: Bjorkholm
authors.forename: H
authors.initials: H
authors.lastname: Gursky
authors.forename: B
authors.initials: B
authors.lastname: Harris