气候变化领域集成服务门户(CCPortal): Lower crustal earthquake associated with highly pressurized frictional melts

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DOI	10.1038/s41561-021-00760-x
	Lower crustal earthquake associated with highly pressurized frictional melts
	Zhong X.; Petley-Ragan A.J.; Incel S.H.M.; Dabrowski M.; Andersen N.H.; Jamtveit B.
发表日期	2021
ISSN	17520894
起始页码	519
结束页码	525
卷号	14 期号:7
英文摘要	Earthquakes at lower crustal depths are common during continental collision. However, the coseismic weakening mechanisms required to propagate an earthquake at high pressures are poorly understood. Transient high-pressure fluids or melts have been proposed as a viable mechanism, but verifying this requires direct in situ measurement of fluid or melt overpressure along fault planes that have hosted dynamic ruptures. Here, we report direct measurement of highly overpressurized frictional melts along a seismic fault surface. Using Raman spectroscopy, we identified high-pressure quartz inclusions sealed in dendritic garnets that grew from frictional melts formed by lower crustal earthquakes in the Bergen Arcs, Western Norway. Melt pressure was estimated to be 1.8–2.3 GPa on the basis of an elastic model for the quartz-in-garnet system. This is ~0.5 GPa higher than the pressure recorded by the surrounding pseudotachylyte matrix and wall rocks. The recorded melt pressure could not arise solely from the volume expansion of melting, and we propose that it was generated when melt pressure approached the maximum principal stress in a system subject to high differential stress. The associated palaeostress field demonstrates that a strong lower crust accommodated up to 1 GPa differential stress during the compressive stage of the Caledonian orogeny. © 2021, The Author(s).
英文关键词	Caledonian orogeny; earthquake event; in situ measurement; lower crust; overpressure; paleostress; pseudotachylite; Bergen Arcs; Hordaland; Norway; Norway
语种	英语
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/206982
作者单位	Physics of Geological Processes, The Njord Centre, Department of Geosciences, University of Oslo, Oslo, Norway; Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany; Institute for Geology, Mineralogy, and Geophysics, Ruhr University Bochum, Bochum, Germany; Computational Geology Laboratory, Polish Geological Institute – NRI, Wrocław, Poland; Department of Chemistry, University of Oslo, Oslo, Norway
推荐引用方式 GB/T 7714	Zhong X.,Petley-Ragan A.J.,Incel S.H.M.,et al. Lower crustal earthquake associated with highly pressurized frictional melts[J],2021,14(7).
APA	Zhong X.,Petley-Ragan A.J.,Incel S.H.M.,Dabrowski M.,Andersen N.H.,&Jamtveit B..(2021).Lower crustal earthquake associated with highly pressurized frictional melts.Nature Geoscience,14(7).
MLA	Zhong X.,et al."Lower crustal earthquake associated with highly pressurized frictional melts".Nature Geoscience 14.7(2021).