气候变化领域集成服务门户(CCPortal): Natural and Experimental Constraints on a Flow Law for Dislocation-Dominated Creep in Wet Quartz

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DOI	10.1029/2020JB021302
	Natural and Experimental Constraints on a Flow Law for Dislocation-Dominated Creep in Wet Quartz
	Lusk A.D.J.; Platt J.P.; Platt J.A.
发表日期	2021
ISSN	21699313
卷号	126 期号:5
英文摘要	We present a flow law for dislocation-dominated creep in wet quartz derived from compiled experimental and field-based rheological data. By integrating the field-based data, including independently calculated strain rates, deformation temperatures, pressures, and differential stresses, we add constraints for dislocation-dominated creep at conditions unattainable in quartz deformation experiments. A Markov Chain Monte Carlo (MCMC) statistical analysis computes internally consistent parameters for the generalized flow law: (Formula presented.) = Aσn (Formula presented.) e−(Q+VP)/RT. From this initial analysis, we identify different effective stress exponents for quartz deformed at confining pressures above and below ∼700 MPa. To minimize the possible effect of confining pressure, compiled data are separated into “low-pressure” (<560 MPa) and “high-pressure” (700–1,600 MPa) groups and reanalyzed using the MCMC approach. The “low-pressure” data set, which is most applicable at midcrustal to lower-crustal confining pressures, yields the following parameters: log(A) = −9.30 ± 0.66 MPa−n−r s−1; n = 3.5 ± 0.2; r = 0.49 ± 0.13; Q = 118 ± 5 kJ mol−1; and V = 2.59 ± 2.45 cm3 mol−1. The “high-pressure” data set produces a different set of parameters: log(A) = −7.90 ± 0.34 MPa−n−r s−1; n = 2.0 ± 0.1; r = 0.49 ± 0.13; Q = 77 ± 8 kJ mol−1; and V = 2.59 ± 2.45 cm3 mol−1. Predicted quartz rheology is compared to other flow laws for dislocation creep; the calibrations presented in this study predict faster strain rates under geological conditions by more than 1 order of magnitude. The change in n at high confining pressure may result from an increase in the activity of grain size sensitive creep. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	dislocation creep; ductile deformation; experimental deformation; flow law; quartz; 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/187147
作者单位	Department of Geoscience, University of Wisconsin-Madison, Madison, WI, United States; Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States; Department of Physics, University of California San Diego, La Jolla, CA, United States
推荐引用方式 GB/T 7714	Lusk A.D.J.,Platt J.P.,Platt J.A.. Natural and Experimental Constraints on a Flow Law for Dislocation-Dominated Creep in Wet Quartz[J],2021,126(5).
APA	Lusk A.D.J.,Platt J.P.,&Platt J.A..(2021).Natural and Experimental Constraints on a Flow Law for Dislocation-Dominated Creep in Wet Quartz.Journal of Geophysical Research: Solid Earth,126(5).
MLA	Lusk A.D.J.,et al."Natural and Experimental Constraints on a Flow Law for Dislocation-Dominated Creep in Wet Quartz".Journal of Geophysical Research: Solid Earth 126.5(2021).