| DOI: | 10.1038/s41561-019-0523-3
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| 论文题名: | Slab weakening during the olivine to ringwoodite transition in the mantle |
| 作者: | Mohiuddin A.; Karato S.-I.; Girard J.
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| 刊名: | Nature Geoscience
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| ISSN: | 17520894
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| 出版年: | 2020
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| 卷: | 13, 期:2 | | 起始页码: | 170
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| 结束页码: | 174
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| 语种: | 英语
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| 英文关键词: | grain size
; mantle convection
; olivine
; phase transition
; reaction kinetics
; ringwoodite
; slab
; subduction zone
; transition zone
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| 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. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/169649
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| Appears in Collections: | 气候变化与战略
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作者单位: | Yale University, Department of Geology and Geophysics, New Haven, CT, United States
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| Recommended Citation: | |
Mohiuddin A.,Karato S.-I.,Girard J.. Slab weakening during the olivine to ringwoodite transition in the mantle[J]. Nature Geoscience,2020-01-01,13(2)
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