%0 Journal Article %T Formation of the Lunar Primary Crust From a Long-Lived Slushy Magma Ocean %+ Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE) %+ Institut Universitaire de France (IUF) %A Michaut, Chloé %A Neufeld, Jerome A. %< avec comité de lecture %@ 0094-8276 %J Geophysical Research Letters %I American Geophysical Union %V 49 %8 2022 %D 2022 %Z 2022GeoRL..4995408M %R 10.1029/2021GL095408 %K magma ocean %K lunar anorthosite %K lunar crust %K suspension %Z Sciences of the Universe [physics] %Z Sciences of the Universe [physics]/Earth SciencesJournal articles %X Classical fractional crystallization scenarios of early lunar evolution suggest crustal formation by the flotation of light anorthite minerals from a liquid magma ocean. However, this model is challenged by the >200$ > 200$ Myr age range of primitive ferroan anorthosites, their concordance with Mg-suite magmatism and by the compositional diversity observed in lunar anorthosites. Here, we propose a new model of slushy magma ocean crystallization in which crystals remain suspended in the lunar interior and crust formation only begins once a critical crystal content is reached. Thereafter crustal formation occurs by buoyant melt extraction and magmatism. The mixture viscosity strongly depends on temperature and solid fraction driving the development of a surface stagnant lid where enhanced solidification and buoyant ascent of melt lead to an anorthite-enriched crust. This model explains lunar anorthosites heterogeneity and suggests a crustal formation timescale of 100s Ma, reconciling anorthosite ages with an early age of the Moon. %G English %2 https://insu.hal.science/insu-03710174/document %2 https://insu.hal.science/insu-03710174/file/Geophysical%20Research%20Letters%20-%202022%20-%20Michaut%20-%20Formation%20of%20the%20Lunar%20Primary%20Crust%20From%20a%20Long%25u2010Lived%20Slushy%20Magma%20Ocean.pdf %L insu-03710174 %U https://insu.hal.science/insu-03710174 %~ UNIV-ST-ETIENNE %~ ENS-LYON %~ INSU %~ CNRS %~ UNIV-LYON1 %~ LGL-TPE %~ UDL %~ UNIV-LYON