Pristine highland clasts in Consortium Breccia 14305: Petrology and geochemistry

The Apollo 14 site continues to provide pristine non mare rocks that contrast sharply with those from Apollo 16, the archetypical highland site. We characterize six small (<1 cm) samples of pristine highland crust that occur as clasts in polymict lunar breccia 14305. One is an alkali anorthosite; the others include troctolite, norite, and anorthosite of the Mg‐suite. The alkali anorthosite (,400) is a plagioclase adcumulate with minor intercumulus augite. Cerian fluorapatite with LREE‐contents ≅30,000 x chondrite occurs as an inclusion in plagioclase. Enstatite troctolite, 358 and magnesian anorthosite, 361 have trace element characteristics similar to “eastern” Mg‐suite rocks, highlighting the importance of local variations in geochemical systematics that are superimposed on moon‐wide, longitudinal variations. The highly fractionated trace element abundances and highly magnesian mineral compositions of olivine orthopyroxenite, 389 suggest a new, previously unknown magma‐type related to the Mg‐suite. This magma may have formed in equilibrium with garnet. Alkali anorthosites and magnesian anorthosites‐troctolites cannot be related to a single parent magma by fractional crystallization or by variable KREEP assimilation. These suites represent separate parent magmas, each of which may have been modified by mixing with KREEP.