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Frictional properties of exhumed fault gouges in DFDP-1 cores, Alpine Fault, New Zealand

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journal contribution
posted on 09.02.2021, 19:10 by Carolyn Boulton, D Moore, D Lockner, V Toy, John Townend, Rupert Sutherland
Principal slip zone gouges recovered during the Deep Fault Drilling Project (DFDP-1), Alpine Fault, New Zealand, were deformed in triaxial friction experiments at temperatures, T, of up to 350°C, effective normal stresses, σn′, of up to 156 MPa, and velocities between 0.01 and 3 μm/s. Chlorite/white mica-bearing DFDP-1A blue gouge, 90.62 m sample depth, is frictionally strong (friction coefficient, μ, 0.61-0.76) across all experimental conditions tested (T = 70-350°C, σn′ = 31.2-156 MPa); it undergoes a transition from positive to negative rate dependence as T increases past 210°C. The friction coefficient of smectite-bearing DFDP-1B brown gouge, 128.42 m sample depth, increases from 0.49 to 0.74 with increasing temperature and pressure (T = 70-210°C, σn′ = 31.2-93.6 MPa); the positive to negative rate dependence transition occurs as T increases past 140°C. These measurements indicate that, in the absence of elevated pore fluid pressures, DFDP-1 gouges are frictionally strong under conditions representative of the seismogenic crust.

History

Preferred citation

Boulton, C., Moore, D., Lockner, D., Toy, V., Townend, J. & Sutherland, R. (2014). Frictional properties of exhumed fault gouges in DFDP-1 cores, Alpine Fault, New Zealand. Geophysical Research Letters, 41(2), 356-362. https://doi.org/10.1002/2013GL058236

Journal title

Geophysical Research Letters

Volume

41

Issue

2

Publication date

01/01/2014

Pagination

356-362

Publisher

American Geophysical Union (AGU)

Publication status

Published

Contribution type

Article

Online publication date

27/01/2014

ISSN

0094-8276

eISSN

1944-8007

Article number

2

Language

en