Asymmetric Early Crust-Building Magmatism on the Lunar Nearside Due to KREEP-Induced Melting Point Depression

[摘要] The lunar magnesian-suite, or Mg-suite, is a series of ancient plutonic rocks from the lunar crust with ages and compositions indicating that they represent crust-building magmatism occurring immediately after the end of magma ocean crystallization. Samples of the Mg-suite were found at every Apollo landing site except 11 and ubiquitously have geochemical characteristics indicating the involvement of KREEP in their petrogenesis. This observation has led to the suggestion that the presence of the KREEP reservoir under the lunar nearside was responsible for this episode of crust building. The lack of any readily identifiable Mg-suite rocks in meteoritic regolith breccias sourced from outside the Procellarum KREEP Terrane (PKT) seemingly supports this interpretation.

[发布日期] 2018-03-19

[学科分类] 空间科学

[关键词] ASYMMETRY;GEOCHEMISTRY;IGNEOUS ROCKS;KREEP;LUNAR CRUST;MAGNESIUM;MAGMA;OLIVINE;PETROGENESIS;CRYSTALLIZATION;LUNAR LANDING SITES;MASS DISTRIBUTION;MELTING POINTS;PLAGIOCLASE;RADIOGENIC MATERIALS;TRACE ELEMENTS