- Lunar magma ocean
According to the
giant impact hypothesis a large amount of energy was liberated in the formation of the Moon and it is predicted that as a result a large portion of the Moon was once completely molten, forming a lunar magma ocean. Evidence for the magma ocean hypothesis comes from the highlyanorthositic compositions of the crust in the lunar highlands, as well as the existence of rocks with a high concentration of the geochemical component referred to asKREEP .Ages of formation and crystallization of the lunar magma ocean have been constrained by studies of isotopes of
hafnium ,tungsten ,samarium , andneodymium . The magma ocean formed about 70 million years after the history of oursolar system began, and most of the ocean was crystallizing at about 215 million years after that beginning (Brandon, 2007).References
* Alan Brandon (2007) Planetary science: A younger moon. Nature 450, 1169-1170. doi:10.1038/4501169a http://origin.www.nature.com/nature/journal/v450/n7173/full/4501169a.html
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Extended Scientific References
* Wood, J. A., Dickey, J. S., Jr., Marvin, U. B., and Powell, B. N. (1970) Lunar Anorthosites. Science, v. 167, no. 3918, p. 602.
* Wood, J. A. (1972) Thermal History and Early Magmatism in the Moon. Icarus, v.16(2), p. 229-240.
* Wood, J. A. (1972) Fragments of Terra Rock in the Apollo 12 Soil Samples and a Structural Model of the Moon. Icarus, v. 16(3), p. 462-501.
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