Campus Units

Geological and Atmospheric Sciences

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

2018

Journal or Book Title

Journal of Structural Geology

Volume

113

First Page

90

Last Page

99

DOI

10.1016/j.jsg.2018.05.022

Abstract

The co-existence and interaction between brittle and viscous deformation processes contributes to the integrated strength of the crust and results in a wide range of energy-release mechanisms ranging from earthquakes to creep. Here, we compare flow laws derived for quartz-rich rocks deforming by brittle creep, wet dislocation power-law creep and dissolution-precipitation creep. We investigate theoretically the conditions when both brittle and viscous processes contribute significantly to deformation provided that all processes act independently and in parallel. Utilizing a comprehensive data set for deformation experiments in quartz-rich rocks, we find that the transition between deformation mechanisms is strongly dependent on input variables such as initial flaw size and grain size. The transition can occur abruptly or over hundreds of MPa in differential stress and hundreds of degrees Kelvin at a constant strain rate. The transition is strongly dependent on grain-size and confining pressure. Limitations to this work are first that all three flow laws are poorly constrained by experimental data for conditions relevant for the comparison. Secondly, a need exists for new experiments to infill the knowledge gaps between high-temperature and low-temperature deformation experiments and deriving quantitative flow laws for low-temperature plasticity and high-temperature brittle creep.

Comments

This is a manuscript of an article published as Reber, Jacqueline E., and Matej Pec. "Comparison of brittle-and viscous creep in quartzites: Implications for semi-brittle flow of rocks." 113 Journal of Structural Geology (2018): 90-99. DOI: 10.1016/j.jsg.2018.05.022. Posted with permission.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Copyright Owner

Elsevier Ltd.

Language

en

File Format

application/pdf

Available for download on Wednesday, May 29, 2019

Published Version

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