Formation of the Lunar Primary Crust From a Long-Lived Slushy Magma Ocean.
Geophys Res Lett
American Geophysical Union (AGU)
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Michaut, C., & Neufeld, J. A. (2022). Formation of the Lunar Primary Crust From a Long-Lived Slushy Magma Ocean.. Geophys Res Lett, 49 (2) https://doi.org/10.1029/2021GL095408
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 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.
Planets, GEODESY AND GRAVITY, Lunar and planetary geodesy and gravity, PLANETARY SCIENCES: SOLID SURFACE PLANETS, Origin and evolution, Volcanism, Gravitational fields, Orbital and rotational dynamics, PLANETARY SCIENCES: FLUID PLANETS, PLANETARY SCIENCES: COMETS AND SMALL BODIES, PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS, Moon, TECTONOPHYSICS, Planetary volcanism, VOLCANOLOGY, Research Letter, magma ocean, lunar anorthosite, lunar crust, suspension
Is supplemented by: https://doi.org/10.17863/CAM.73500
EC, H2020, H2020 Priority Excellent Science, H2020 European Research Council (ERC) (101001689)
University of Lyon (ANR‐16‐IDEX‐0005)
External DOI: https://doi.org/10.1029/2021GL095408
This record's URL: https://www.repository.cam.ac.uk/handle/1810/333030