气候变化领域集成服务门户(CCPortal): Slab weakening during the olivine to ringwoodite transition in the mantle

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DOI	10.1038/s41561-019-0523-3
	Slab weakening during the olivine to ringwoodite transition in the mantle
	Mohiuddin A.; Karato S.-I.; Girard J.
发表日期	2020
ISSN	17520894
卷号	13 期号:2
英文摘要	The strength of subducted slabs in the mantle transition zone influences the style of mantle convection. Intense deformation is observed particularly in relatively old subducted slabs in the deep mantle transition zone. Understanding the cause of this regional and depth variation in slab deformation requires constraint of the rheological properties of deep mantle materials. Here, we report results of in situ deformation experiments during the olivine to ringwoodite phase transformation, from which we infer the deformation process under the conditions of cold slabs deep in the mantle transition zone. We find that newly transformed fine-grained ringwoodite deforms by diffusion creep and that its strength is substantially smaller than that of coarser-grained minerals but increases with time. Scaling analysis, based on a model of transformation kinetics and grain-size evolution during a phase transformation, suggests that a cold slab will be made of a mixture of weak, fine-grained and strong, coarse-grained materials in the deep transition zone, whereas a warm slab remains strong because of its large grain size. We propose that this temperature dependence of grain size may explain extensive deformation of cold slabs in the deep transition zone but limited deformation of relatively warm slabs. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	grain size; mantle convection; olivine; phase transition; reaction kinetics; ringwoodite; slab; subduction zone; 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/124511
作者单位	Yale University, Department of Geology and Geophysics, New Haven, CT, United States
推荐引用方式 GB/T 7714	Mohiuddin A.,Karato S.-I.,Girard J.. Slab weakening during the olivine to ringwoodite transition in the mantle[J],2020,13(2).
APA	Mohiuddin A.,Karato S.-I.,&Girard J..(2020).Slab weakening during the olivine to ringwoodite transition in the mantle.Nature Geoscience,13(2).
MLA	Mohiuddin A.,et al."Slab weakening during the olivine to ringwoodite transition in the mantle".Nature Geoscience 13.2(2020).