論文

査読有り
2010年6月15日

Coupled 182W-142Nd constraint for early earth differentiation

Proceedings of the National Academy of Sciences of the United States of America
  • Frederic Moynier
  • ,
  • Qing-Zhu Yin
  • ,
  • Keita Irisawa
  • ,
  • Maud Boyet
  • ,
  • Benjamin Jacobsen
  • ,
  • Minik T. Rosing

107
24
開始ページ
10810
終了ページ
10814
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1073/pnas.0913605107
出版者・発行元
Proceedings of the National Academy of Sciences

Recent high precision 142Nd isotope measurements showed that global silicate differentiation may have occurred as early as 30-75 Myr after the Solar System formation [Bennett V, et al. (2007) Science 318:1907-1910]. This time scale is almost contemporaneous with Earth's core formation at ∼30 Myr [Yin Q, et al. (2002) Nature 418:949-952]. The 182Hf- 182W system provides a powerful complement to the 142Nd results for early silicate differentiation, because both core formation and silicate differentiation fractionate Hf from W. Here we show that eleven terrestrial samples from diverse tectonic settings, including five early Archean samples from Isua, Greenland, of which three have been previously shown with 142Nd anomalies, all have a homogeneous W isotopic composition, which is ∼2ε-unit more radiogenic than the chondritic value. By using a 3-stage model calculation that describes the isotopic evolution in chondritic reservoir and core segregation, as well as silicate differentiation, we show that the Wisotopic composition of terrestrial samples provides the most stringent time constraint for early core formation (27.5-38 Myr) followed by early terrestrial silicate differentiation (38-75 Myr) that is consistent with the terrestrial 142Nd anomalies.

リンク情報
DOI
https://doi.org/10.1073/pnas.0913605107
URL
https://syndication.highwire.org/content/doi/10.1073/pnas.0913605107
ID情報
  • DOI : 10.1073/pnas.0913605107
  • ISSN : 0027-8424
  • ISSN : 1091-6490
  • eISSN : 1091-6490
  • SCOPUS ID : 77954650581

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