Foraging westward for pristine nonmare rocks - Complications for petrogenetic models

New advances are reported concerning an investigation which is being conducted to find and characterize more 'pristine' (compositionally endogenous) lunar rocks. Eleven nonmare samples are characterized petrographically and (except for two clasts that were prohibitively small) by chemical composition. The samples are assessed whether they are pristine on the basis of diagnostic features discussed by Warren and Wasson (1977). Five samples are found to be almost certainly pristine. They include the alkali-rich anorthosite 12073c, the troctolite 14179c, the anorthositic troctolite 14321c1, the troctolitic anorthosite 14321c2, and the anorthositic norite 15565c. Correlations between petrochemistry and longitude are also investigated, taking into account Eu fractionations, Sc-Ti-Sm fractionations, and Ca/Na-Mg/Fe fractionations.