Persistence and origin of the lunar core dynamo
| Autor: | Lindsey Chan, William S. Cassata, Clément Suavet, Jérôme Gattacceca, Benjamin P. Weiss, Ian Garrick-Bethell, David L. Shuster, Timothy L. Grove, Michael D Fuller, James W. Head |
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| Rok vydání: | 2013 |
| Předmět: |
Basalt
Convection Multidisciplinary Champ magnetique Geophysics Mantle (geology) Physics::Geophysics Magnetic field Physical Sciences Physics::Space Physics Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Mercury's magnetic field Solar dynamo Geology Dynamo |
| Zdroj: | Proceedings of the National Academy of Sciences. 110:8453-8458 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1300341110 |
| Popis: | The lifetime of the ancient lunar core dynamo has implications for its power source and the mechanism of field generation. Here, we report analyses of two 3.56-Gy-old mare basalts demonstrating that they were magnetized in a stable and surprisingly intense dynamo magnetic field of at least ∼13 μT. These data extend the known lifetime of the lunar dynamo by ∼160 My and indicate that the field was likely continuously active until well after the final large basin-forming impact. This likely excludes impact-driven changes in rotation rate as the source of the dynamo at this time in lunar history. Rather, our results require a persistent power source like precession of the lunar mantle or a compositional convection dynamo. |
| Databáze: | OpenAIRE |
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