Craig, TJ, Copley, A and Middleton, TA (2014) Constraining fault friction in oceanic lithosphere using the dip angles of newly-formed faults at outer rises. Earth and Planetary Science Letters, 392. pp. 94-99. ISSN 0012-821X
Abstract
We investigate the mechanical properties of the oceanic lithosphere using earthquake focal mechanisms from subduction zone outer rises. We study regions where faulting oblique to the pre-existing mid-ocean ridge fabric implies the formation of new faults. The nodal-plane dips of dip-slip earthquakes on these faults are dominantly in the range 30–60°, with a strong peak concentrated around 45°. This distribution is inconsistent with the pattern that would result from high coefficients of friction (e.g. 0.6, equivalent to normal faults forming at 60° and thrust faults at 30°). We instead suggest that the observed distribution of dips implies that faults in the oceanic lithosphere have a low coefficient of friction, due to either low-friction clay minerals formed by hydrothermal alteration at the ridge, or due to an intrinsic level of friction that is lower than that suggested by laboratory studies.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | (c) 2014, The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/). |
Keywords: | fault friction; oceanic lithosphere; rheology; outer rise |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 01 Apr 2016 08:10 |
Last Modified: | 12 Feb 2019 13:29 |
Published Version: | http://dx.doi.org/10.1016/j.epsl.2014.02.024 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.epsl.2014.02.024 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:92255 |