气候变化领域集成服务门户(CCPortal): Low-Temperature Plasticity and Dislocation Creep of Fangshan Dolomite

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DOI	10.1029/2020JB021439
	Low-Temperature Plasticity and Dislocation Creep of Fangshan Dolomite
	Li J.; Shao T.; Song M.; Wang H.
发表日期	2021
ISSN	21699313
卷号	126 期号:5
英文摘要	To explore the rheology of dolomite and investigate recent findings regarding the so-called inversion of activation energy between dislocation and diffusion creep, we compressed medium-grained Fangshan dolomite (113 ± 42 µm) at effective confining pressures of 50–300 MPa, temperatures of 27°C–900°C, and strain rates of 10−6 to 2 × 10−4 s−1 using a Paterson gas-medium apparatus. Two end-member deformation regimes with corresponding diagnostic flow laws and microstructures were identified. At temperatures ≤500°C, low-temperature plasticity (LTP), which is characterized by microstructures of predominant abrupt undulatory extinctions and f-twins, was determined to dominate the deformation of Fangshan dolomite. The corresponding flow behavior can be described by an (Formula presented.) with (Formula presented.) and (Formula presented.) (Regime 1). At temperatures ≥800°C, dislocation creep, which shows characteristic microstructures of smooth undulating extinction and new recrystallized grains, dominated the deformation of Fangshan dolomite. The corresponding flow behavior can be expressed by a power law equation, (Formula presented.) with (Formula presented.), (Formula presented.), and (Formula presented.) (Regime 2). At temperatures between ∼500 and 800°C, a transition regime between LTP and dislocation creep was identified (Regime 3) with the dependence of flow stress on strain rate increasing gradually with increasing temperature. When extrapolated to natural conditions, our flow law of dislocation creep for dolomite in combination with that of diffusion creep reported by Davis et al. (2008) suggests that the dislocation creep regime of dolomite is limited to a relatively narrow region of high temperature and relatively high stress, whereas the diffusion creep regime dominates the deformation of dolomite in tectonic settings with low stress levels. © 2021. The Authors.
英文关键词	activation energy; dislocation creep; dolomite; high temperature and high pressure; low-temperature plasticity; rheology
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/187113
作者单位	State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, China
推荐引用方式 GB/T 7714	Li J.,Shao T.,Song M.,et al. Low-Temperature Plasticity and Dislocation Creep of Fangshan Dolomite[J],2021,126(5).
APA	Li J.,Shao T.,Song M.,&Wang H..(2021).Low-Temperature Plasticity and Dislocation Creep of Fangshan Dolomite.Journal of Geophysical Research: Solid Earth,126(5).
MLA	Li J.,et al."Low-Temperature Plasticity and Dislocation Creep of Fangshan Dolomite".Journal of Geophysical Research: Solid Earth 126.5(2021).