DOI: 10.1038/s41561-018-0084-x
论文题名: Accretion mode of oceanic ridges governed by axial mechanical strength
作者: Sibrant A.L.R. ; Mittelstaedt E. ; Davaille A. ; Pauchard L. ; Aubertin A. ; Auffray L. ; Pidoux R.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2018
卷: 11, 期: 4 起始页码: 274
结束页码: 279
语种: 英语
英文摘要: Oceanic spreading ridges exhibit structural changes as a function of spreading rate, mantle temperature and the balance of tectonic and magmatic accretion. The role that these or other processes have in governing the overall shape of oceanic ridges is unclear. Here, we use laboratory experiments to simulate ridge spreading in colloidal aqueous dispersions whose rheology evolves from purely viscous to elastic and brittle when placed in contact with a saline water solution. We find that ridge shape becomes increasingly linear with spreading rate until reaching a minimum tortuosity. This behaviour is predicted by the axial failure parameter Π F, a dimensionless number describing the balance of brittle and plastic failure of axial lithosphere. Slow-spreading, fault-dominated and fast-spreading, fluid intrusion-dominated ridges on Earth and in the laboratory are separated by the same critical Π F value, suggesting that the axial failure mode governs ridge geometry. Values of Π F can also be calculated for different mantle temperatures and applied to other planets or the early Earth. For higher mantle temperatures during the Archaean, our results preclude the predicted formation of large tectonic plates at high spreading velocity. © 2018 The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105577
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Department of Geological Sciences, University of Idaho, Moscow, ID, United States; Laboratoire FAST, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
Recommended Citation:
Sibrant A.L.R.,Mittelstaedt E.,Davaille A.,et al. Accretion mode of oceanic ridges governed by axial mechanical strength[J]. Nature Geoscience,2018-01-01,11(4)