title: Chemical Composition of the Lunar Surface in a Terra Region near the Crater Tycho.
abstract: More precise and comprehensive analytical results for lunar surface material in a terra region have been derived from the data of the alpha-scattering experiment on Surveyor 7. The silicon content and the low sodium abundance are close to that of mare material. The abundances of titanium and iron are at least a factor of 2 lower, whereas the abundances of aluminum and calcium are significantly higher. The analytical results provide direct evidence for chemical differentiation in the moon and indicate a lunar crust of appreciably lower density than the whole moon and with lower density and higher albedo than lunar mare material.
authors.forename: J H
authors.initials: JH
authors.lastname: Patterson
authors.forename: A L
authors.initials: AL
authors.lastname: Turkevich
authors.forename: E J
authors.initials: EJ
authors.lastname: Franzgrote
authors.forename: T E
authors.initials: TE
authors.lastname: Economou
authors.forename: K P
authors.initials: KP
authors.lastname: Sowinski