气候变化领域集成服务门户(CCPortal): Crystal-Plastic Deformation in Seismically Active Carbonate Fault Rocks

CCPortal

DOI	10.1029/2020JB020626
	Crystal-Plastic Deformation in Seismically Active Carbonate Fault Rocks
	Ohl M.; Nzogang B.; Mussi A.; Wallis D.; Drury M.; Plümper O.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	The spatial separation of macroscopic rheological behaviors has led to independent conceptual treatments of frictional failure, often referred to as brittle, and viscous deformation. Detailed microstructural investigations of naturally deformed carbonate rocks indicate that both frictional failure and viscous mechanisms might operate during seismic deformation of carbonates. Here, we investigate the deformation mechanisms that were active in two carbonate fault zones in Greece by performing detailed slip-system analyses on data from automated crystal-orientation mapping transmission electron microscopy and electron-backscatter diffraction. We combine the slip-system analyses with interpretations of nanostructures and predictions from deformation mechanism maps for calcite. The nanometric grains at the principal slip surface should deform by diffusion creep but the activation of the (0001)< (Formula presented.) 2 (Formula presented.) 0> slip system is evidence for a contribution of crystal plasticity. A similar crystallographic preferred orientation appears in the cataclastic parts of the fault rocks despite exhibiting a larger grain size and a different fractal dimension, compared to the principal slip surface. The cataclastic region exhibits microstructures consistent with activation of the (0001)< (Formula presented.) 2 (Formula presented.) 0> and {10 (Formula presented.) 4}< (Formula presented.) 021> slip systems. Postdeformational, static recrystallization, and annealing produce an equilibrium microstructure with triple junctions and equant grain size. We propose that repeated introduction of plastic strain and recrystallization reduces the grain size and offers a mechanism to form a cohesive nanogranular material. This formation mechanism leads to a grain-boundary strengthening effect resulting in slip delocalization which is observed over 6 orders of magnitude (μm-m) and is expressed by multiple faults planes, suggesting cyclic repetition of deformation and annealing. © 2021. The Authors.
英文关键词	calcite CPO; carbonate deformation; crystal plasticity; microstructures; recrystallization; seismic cycle
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/187195
作者单位	Department of Earth Sciences, Utrecht University, Utrecht, Netherlands; Univ. Lille, CNRS, INRAE, ENSCL, UMR 8207-UMET—Unité Matériaux et Transformations, Lille, France; Now at Department of Earth Sciences, University of Cambridge, Cambridge, United Kingdom
推荐引用方式 GB/T 7714	Ohl M.,Nzogang B.,Mussi A.,et al. Crystal-Plastic Deformation in Seismically Active Carbonate Fault Rocks[J],2021,126(4).
APA	Ohl M.,Nzogang B.,Mussi A.,Wallis D.,Drury M.,&Plümper O..(2021).Crystal-Plastic Deformation in Seismically Active Carbonate Fault Rocks.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Ohl M.,et al."Crystal-Plastic Deformation in Seismically Active Carbonate Fault Rocks".Journal of Geophysical Research: Solid Earth 126.4(2021).