KREEP
basalt enriched in potassium, rare earths, and associated elements; low- potassium basalt; norite; dunite; and breccias (Taylor 1975, Gillett 1983).
The mare rock types are composed primarily of plagioclase feldspars, clinopyroxenes, and ilmenite, with minor olivine, chromite/ulvospinel, iiihd tridymite/cristobalite (Taylor 1975). The highland rock types are composed primarily of plagioclase feldspars, orthopyroxenes, and olivine, along with minor ilmenite (Taylor 1975). The whole rocks represent a potential source of these minerals and someday may be used as a feedstock because they would supply material of relatively uniform physical characteristics, but their use would require an extensive infrastructure for mining and processing. The regolith fines will probably be exploited first because they have already been pulverized by meteoritic and cometary bombardment. The ranges of modal abundances for the major lunar minerals in various rock type~ are shown in table 5. The ranges of chemical compositions for the major lunar minerals in various rock types are shown in table 6.
