气候变化领域集成服务门户(CCPortal): Sharp 660-km discontinuity controlled by extremely narrow binary post-spinel transition

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DOI	10.1038/s41561-019-0452-1
	Sharp 660-km discontinuity controlled by extremely narrow binary post-spinel transition
	Ishii T.; Huang R.; Myhill R.; Fei H.; Koemets I.; Liu Z.; Maeda F.; Yuan L.; Wang L.; Druzhbin D.; Yamamoto T.; Bhat S.; Farla R.; Kawazoe T.; Tsujino N.; Kulik E.; Higo Y.; Tange Y.; Katsura T.
发表日期	2019
ISSN	17520894
卷号	12 期号:10
英文摘要	The Earth’s mantle is characterized by a sharp seismic discontinuity at a depth of 660 km that can provide insights into deep mantle processes. The discontinuity occurs over only 2 km—or a pressure difference of 0.1 GPa—and is thought to result from the post-spinel transition, that is, the decomposition of the mineral ringwoodite to bridgmanite plus ferropericlase. Existing high-pressure, high-temperature experiments have lacked the pressure control required to test whether such sharpness is the result of isochemical phase relations or chemically distinct upper and lower mantle domains. Here, we obtain the isothermal pressure interval of the Mg–Fe binary post-spinel transition by applying advanced multi-anvil techniques with in situ X-ray diffraction with the help of Mg–Fe partition experiments. It is demonstrated that the interval at mantle compositions and temperatures is only 0.01 GPa, corresponding to 250 m. This interval is indistinguishable from zero at seismic frequencies. These results can explain the discontinuity sharpness and provide new support for whole-mantle convection in a chemically homogeneous mantle. The present work suggests that distribution of adiabatic vertical flows between the upper and lower mantles can be mapped on the basis of discontinuity sharpness. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	high pressure; high temperature; homogeneity; isotherm; lower mantle; mantle convection; mantle discontinuity; ringwoodite; seismic velocity
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/124593
作者单位	Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany; School of Earth Sciences, University of Bristol, Bristol, United Kingdom; Department of Earth Sciences, Graduate School of Science, Tohoku University, Sendai, Japan; Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan; Deutsche Elektronen-Synchrotron, Hamburg, Germany; Institute for Study of the Earth’s Interior, Okayama University, Misasa, Japan; Japan Synchrotron Radiation Research Institute, Sayo-gun, Japan; Center for High Pressure Science and Technology Advanced Research, Beijing, China
推荐引用方式 GB/T 7714	Ishii T.,Huang R.,Myhill R.,et al. Sharp 660-km discontinuity controlled by extremely narrow binary post-spinel transition[J],2019,12(10).
APA	Ishii T..,Huang R..,Myhill R..,Fei H..,Koemets I..,...&Katsura T..(2019).Sharp 660-km discontinuity controlled by extremely narrow binary post-spinel transition.Nature Geoscience,12(10).
MLA	Ishii T.,et al."Sharp 660-km discontinuity controlled by extremely narrow binary post-spinel transition".Nature Geoscience 12.10(2019).