Journal article

Fault spacing in continental strike-slip shear zones

Haibin Yang, Louis N Moresi, Mark Quigley

EARTH AND PLANETARY SCIENCE LETTERS | ELSEVIER | Published : 2020

Abstract

Strike-slip shear zones with sub-parallel arrays of evenly-spaced faults are widely observed in nature, but the controls on the spacing between major faults are unclear. We analyze a 2-D model and develop a scaling law relating the fault spacing to structural and rheological parameters in the continental crust. We find that fault spacing positively correlates with brittle-layer thickness, viscous lower crust thickness, and strength contrast between active faults and surrounding intact blocks; and is inversely correlative with lower crust viscosity. This is corroborated for either a zero-shear traction (decoupled) or a prescribed velocity (coupled) basal boundary condition in the 2-D analytic..

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Grants

Awarded by Australian Research Council


Funding Acknowledgements

We thank the Australian Research Council for funding this research under Discovery Grant DP170103350. Insightful suggestions from the editor Dr. Yin A., critical comments from Dr. Zuza A. and three other anonymous reviewers have greatly improved the clarity and focus of the work. Dr. Eberhart-Phillips provided relocated hypocenters in the MFZ. Dr. Zhou Beibei and Zhu Gaohua provided relocated hypocenters in CTb. Dr. Shinevar shared viscosity estimates in Southern California for comparison. We made use of resources from the National Computational Infrastructure (NCI), as well as the Pawsey Supercomputing Centre. H. Yang received the Baragwanath Travel Scholarship from the University of Melbourne to assist in research development. One figure in this paper was produced by using the Generic Mapping Tools (GMT) package (Wessel et al., 2013).