Interior of the Moon: The presence of garnet in the primitive deep lunar mantle

摘要: New trace element data have been generated by inductively coupled plasma-mass spectrometry (ICP-MS) for 65 high- and low-Ti mare basalts from the Apollo 11, 12, 14, 15, 17 landing sites. These demonstrate that ratios of high field strength elements yttrium are generally chondritic in source regions but nonchondritic high-Ti potassium, rare earth elements, phosphorus (KREEP); such differences can be explained addition subtraction (respectively) ilmenite. This interpretation is consistent with derivation lunar magma ocean (LMO) cumulates through which late stage ilmenite has sunk mixed earlier products. Compositional between volcanic glass beads suggest at least some latter were derived a garnet-bearing region. Siderophile chalcophile escaped LMO melting event thus represents primitive Moon material. The remaining glasses very low Ti (VLT) appear to early (i.e., olivine orthopyroxene, similar VLT basalts). below cumulates, as magmas rose they underwent sequential assimilation (to varying degrees) initially an ilmenite-rich cumulate followed KREEP component. study presents geochemical evidence existence garnet demonstrates likelihood was not “whole Moon,” preserving material, acted region glasses.