Compositional studies of the lunar regolith at the Apollo 17 site

Major-, minor-, and trace-element abundance data are presented for twenty-two Apollo 17 samples, twelve Apollo 16 samples, and one Apollo 15 basalt. The data were obtained by INAA employing a 14 MeV neutron generator, a Cf-252 isotopic neutron source and nuclear reactor thermal neutrons. Abundance summations for the twenty-four samples analyzed for major and minor abundance elements averaged 98.8 plus or minus 0.3%. Similarities between the Apollo 17 and the Apollo 11 mare basalts are discussed. Abundances in 13 Apollo 17 soils exhibit the greatest compositional range we have observed for soils from a specific landing site. A strong inverse Fe-Al correlation in all lunar materials we have analyzed with the exception of most Apollo 16 samples is defined by the equation: %Fe = -1.36 %Al + 21.5. A strong direct Mn-Fe correlation is defined by the equation: %Fe = 75.9 %Mn + 0.08. Both regression lines appear to have the mare basalts, as one end-member and an unspecified Al-rich component at the other end. Comparisons of the data from direct O determinations and calculated O abundances based on normal stoichiometry are presented.