CHED 1673 |
| The formation of the Earth involved several collisions of Moon-to-Mars-sized planetary embryos. One of these late impacts led to the formation of the Moon. The energy released by these collisions resulted in the formation of magma oceans. Processes in these magma oceans led to a chemical differentiation of the Earth and Moon: formation of the Earth's core by metal-silicate separation and crystallization of the lunar magma ocean in chemically distinct layers. The decay of now extinct hafnium-182 to tungsten-182 is well suited to constrain the timing of and processes involved in the accretion and earliest differentiation of the Earth and Moon. Hafnium-tungsten data for the Earth, Moon and meteorites indicate that the final assembly of the Earth and Moon, the formation of Earth's core and the crystallization of the lunar magma ocean occurred 30-50 Myr after the formation of the solar system. |
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Chemical Evolution, Chemical Change Across Space and Time
9:00 AM-11:55 AM, Wednesday, March 28, 2007 McCormick Place North -- Room N227A, Level 2, Oral
Division of Chemical Education |