Evolution of planetary cores and the Earth-Moon system from Nb/Ta systematics

verfasst von

Carsten Münker, Jörg A. Pfänder, Stefan Weyer, Anette Büchl, Thorsten Kleine, Klaus Mezger

Abstract

It has been assumed that Nb and Ta are not fractionated during differentiation processes on terrestrial planets and that both elements are lithophile. High-precision measurements of Nb/Ta and Zr/Hf reveal that Nb is moderately siderophile at high pressures. Nb/Ta values in the bulk silicate Earth (14.0 ± 0.3) and the Moon (17.0 ± 0.8) are below the chondritic ratio of 19.9 ± 0.6, in contrast to Mars and asteroids. The lunar Nb/Ta constrains the mass fraction of impactor material in the Moon to less than 65%. Moreover, the Moon-forming impact can be linked in time with the final core-mantle equilibration on Earth 4.533 billion years ago.

Externe Organisation(en)

Westfälische Wilhelms-Universität Münster (WWU)
Goethe-Universität Frankfurt am Main
Max-Planck-Institut für Chemie (Otto-Hahn-Institut)

Typ

Artikel

Journal

SCIENCE

Band

301

Seiten

84-87

Anzahl der Seiten

4

ISSN

0036-8075

Publikationsdatum

04.07.2003

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Allgemein

Elektronische Version(en)

https://doi.org/10.1126/science.1084662 (Zugang: Unbekannt)