气候变化领域集成服务门户(CCPortal): Metastability and Nondislocation-Based Deformation Mechanisms of the Flem Eclogite in the Western Gneiss Region, Norway

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DOI	10.1029/2020JB019375
	Metastability and Nondislocation-Based Deformation Mechanisms of the Flem Eclogite in the Western Gneiss Region, Norway
	Cao Y.; Du J.; Park M.; Jung S.; Park Y.; Kim D.; Choi S.; Jung H.; Austrheim H.
发表日期	2020
ISSN	21699313
卷号	125 期号:5
英文摘要	The eclogite in the Flem Gabbro from Flemsøya Island of the Western Gneiss Region in Norway contains atypical eclogitic minerals, such as olivine and orthopyroxene, and can be texturally divided into weakly deformed massive eclogite (MEC) and strongly deformed foliated eclogite (FEC). Based on phase equilibria modeling, peak metamorphic pressure-temperature conditions of ~600–750 °C and ~1.0–2.5 GPa and ~700–820 °C and ~2.7–3.7 GPa are recorded in MEC and FEC, respectively. These different pressure-temperature conditions between MEC (high-pressure, HP) and FEC (ultrahigh-pressure, UHP) in the same outcrop reflect deformation-enhanced eclogitization metamorphism (HP to UHP transition) via the addition of external water during subduction/burial to early exhumation stages and metastable preservation of the HP MEC assemblage at UHP condition due to the local lack of deformation and fluid access at the deep subduction interface or around Moho beneath continental collision zone. Based on the mineral microstructures, nondislocation-based creep mechanisms—such as diffusion creep, grain and phase boundary sliding, and rigid-body-like rotation—play dominant roles in governing the deformation features of FEC and developing the crystal preferred orientations of its major constituent minerals. These deformation mechanisms could considerably affect the interplate coupling at the subduction interface or the rheological strength of Moho beneath continental collision zones. Therefore, the effects of metastability-based (i.e., preservation of low-pressure assemblages at HP conditions) and contributions of nondislocation-based creep mechanisms should be included in the future geodynamic and petrological simulations of subduction and collision processes. ©2020. The Authors.
英文关键词	deformation mechanism; eclogite; metastability; Western Gneiss Region
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187843
作者单位	State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan, China; Tectonophysics Laboratory, School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea; School of Earth Sciences and Resources, China University of Geosciences, Beijing, China; Physics of Geological Processes, University of Oslo, Oslo, Norway
推荐引用方式 GB/T 7714	Cao Y.,Du J.,Park M.,et al. Metastability and Nondislocation-Based Deformation Mechanisms of the Flem Eclogite in the Western Gneiss Region, Norway[J],2020,125(5).
APA	Cao Y..,Du J..,Park M..,Jung S..,Park Y..,...&Austrheim H..(2020).Metastability and Nondislocation-Based Deformation Mechanisms of the Flem Eclogite in the Western Gneiss Region, Norway.Journal of Geophysical Research: Solid Earth,125(5).
MLA	Cao Y.,et al."Metastability and Nondislocation-Based Deformation Mechanisms of the Flem Eclogite in the Western Gneiss Region, Norway".Journal of Geophysical Research: Solid Earth 125.5(2020).