Intensive hydration of the mantle transition zone beneath China caused by ancient slab stagnation

Takeshi Kuritani, Eiji Ohtani, Jun Ichi Kimura

研究成果: Article査読

191 被引用数 (Scopus)

抄録

The mantle transition zone, located at depths of 410- 660ĝ€‰km between the lower and upper mantle, is an important water reservoir in the Earthg's interior1-4. However, there are regional-scale heterogeneities in the distribution of water4,5. The zone beneath northeast China, in particular, is remarkably hydrous4, but when and how it became hydrous remains uncertain. Here we combine analyses of the geochemistry of late Cenozoic basalts in northeast China with published geochemical analyses. We find a spatial correlation between basalt geochemistry and the distribution of a low-velocity zone in the underlying mantle that is interpreted as a plume upwelling from the mantle transition zone. We therefore use the basalt geochemistry to infer the composition of the mantle transition zone6. The basalts have high Ba/Th and 207Pb/ 206 Pb ratios, which we suggest record an ancient hydration event in the transition zone that occurred more than one billion years ago, probably as a result of dehydration of a subducted slab. We suggest that this ancient hydration event, combined with a more recent hydration event linked to dehydration of the subducted Pacific slab, can account for the hydrous nature of the mantle transition zone beneath China. Our results demonstrate that the mantle transition zone can remain as a stable water reservoir in Earth's interior for timescales of more than a billion years.

本文言語English
ページ(範囲)713-716
ページ数4
ジャーナルNature Geoscience
4
10
DOI
出版ステータスPublished - 2011 10月

ASJC Scopus subject areas

  • 地球惑星科学(全般)

フィンガープリント

「Intensive hydration of the mantle transition zone beneath China caused by ancient slab stagnation」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル