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verwandte Themen => kleine Astro-Ecke => Thema gestartet von: karmaka am Februar 18, 2012, 21:08:37 Nachmittag

Titel: Bausteine ​​des frühen Erdmantels überdauerten den 'Giant impact'
Beitrag von: karmaka am Februar 18, 2012, 21:08:37 Nachmittag

'Bausteine' ​​des frühen Erdmantels überdauerten den 'Giant impact', die Kollision, die vermutlich vor 4,527 Milliarden Jahren zur Entstehung des Mondes führte

http://www.newsdesk.umd.edu/scitech/release.cfm?ArticleID=2623

http://translate.google.de/translate?sl=en&tl=de&js=n&prev=_t&hl=de&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.newsdesk.umd.edu%2Fscitech%2Frelease.cfm%3FArticleID%3D2623

http://www.sciencemag.org/content/early/2012/02/15/science.1216351

Zitat

Late accretion, early mantle differentiation, and core-mantle interaction are processes that could have created subtle 182W isotopic heterogeneities within Earth's mantle. Tungsten isotopic data for 2.8 Ga Kostomuksha komatiites show a well-resolved 182W excess relative to modern terrestrial samples, whereas data for 3.5 Ga Komati komatiites show no excess. Combined 182W, 186,187Os, and 142,143Nd isotopic data indicate that the mantle source of the Kostomuksha komatiites included material from a primordial reservoir that represents either a deep mantle region that underwent metal-silicate equilibration, or a product of large-scale magmatic differentiation of the mantle. The preservation of this reservoir, likely formed within the first 30 Myr of solar system history, until at least 2.8 Ga, indicates that the mantle may have never been well mixed.

Grüße

Martin