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DOI	10.1038/s41561-021-00850-w
	A poorly mixed mantle transition zone and its thermal state inferred from seismic waves
	Waszek L.; Tauzin B.; Schmerr N.C.; Ballmer M.D.; Afonso J.C.
发表日期	2021
ISSN	1752-0894
卷号	14 期号:12
英文摘要	The abrupt changes in mineralogical properties across the Earth’s mantle transition zone substantially impact convection and thermochemical fluxes between the upper and lower mantle. While the 410-km discontinuity at the top of the mantle transition zone is detected with all types of seismic waves, the 660-km boundary is mostly invisible to underside P-wave reflections (P660P). The cause for this observation is debated. The dissociation of ringwoodite and garnet into lower-mantle minerals both contribute to the ‘660’ visibility; only the garnet reaction favours material exchanges across the discontinuity. Here, we combine large datasets of SS and PP precursors, mineralogical modelling and data-mining techniques to obtain a global thermal map of the mantle transition zone, and explain the lack of P660P visibility. We find that its prevalent absence requires a chemically unequilibrated mantle, and its visibility in few locations is associated with potential temperatures greater than 1,800 K. Such temperatures occur in approximately 0.6% of Earth, indicating that the 660 is dominated by ringwoodite decomposition, which tends to impede mantle flow. We find broad regions with elevated temperatures beneath the Pacific surrounded by major volcanic hotspots, indicating plume retention and ponding of hot materials in the mantle transition zone. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	discontinuity; garnet; mineralogy; P-wave; ringwoodite; seismic wave; transition zone
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/250832
作者单位	Physical Sciences, James Cook University, Douglas, QLD, Australia; Department of Physics, New Mexico State University, Las Cruces, NM, United States; Université de Lyon, UCBL, ENSL, CNRS, LGL-TPE, Villeurbanne, France; Research School of Earth Sciences, Australian National University, Acton, ACT, Australia; Department of Geology, University of Maryland College Park, College Park, MD, United States; Department of Earth Sciences, University College London, London, United Kingdom; Institute of Geophysics, ETH Zurich, Zurich, Switzerland; Department of Earth and Planetary Sciences, Macquarie University, North Ryde, NSW, Australia
推荐引用方式 GB/T 7714	Waszek L.,Tauzin B.,Schmerr N.C.,et al. A poorly mixed mantle transition zone and its thermal state inferred from seismic waves[J],2021,14(12).
APA	Waszek L.,Tauzin B.,Schmerr N.C.,Ballmer M.D.,&Afonso J.C..(2021).A poorly mixed mantle transition zone and its thermal state inferred from seismic waves.Nature Geoscience,14(12).
MLA	Waszek L.,et al."A poorly mixed mantle transition zone and its thermal state inferred from seismic waves".Nature Geoscience 14.12(2021).