Datafiles from elevated temperature velocity-step tests in a triaxial deformation apparatus
Datafiles are from a suite of frictional velocity step experiments on clay-bearing fault gouges, at elevated temperatures up to 180°C. The aim was to test if varying temperature reduces the stability of clay-rich faults, measured by the rate and state friction parameter (a-b). Data were collected in the Rock Deformation Laboratory at the University of Liverpool between Oct 2021 to May 2022 by Dr. Isabel Ashman, as part of her NERC EAO DTP studentship. The datafiles are text files of both the raw voltage and calibrated measurements from triaxial deformation experiments. The stability of synthetic kaolinite clay-bearing fault gouges was found to decrease systematically with elevated temperatures commensurate with those found at typical earthquake depths. In materials containing 25-50% clay, the stability of slip decreased with increasing temperature so that the gouges displayed unstable slip at temperatures between 100 and 180°C. At room temperature the same materials showed stable slip and velocity strengthening characteristics. The reduction in stability with increasing temperature coincides with a greater degree of compaction observed in the gouge microstructure and is inferred to result from progressive loss of water adsorbed on the clay surfaces. These results indicate that clay-bearing fault rocks can nucleate unstable slip at conditions common to the clay-bearing brittle crust; a result that adds to the observations of mature clay-bearing faults in nature that can nucleate and propagate earthquakes.
nonGeographicDataset
https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item188220
name: Data
function: download
https://doi.org/10.5285/7337c4aa-4fe5-4c8f-abe6-75deb0701e03
name: Digital Object Identifier (DOI)
function: information
http://data.bgs.ac.uk/id/dataHolding/13608414
eng
geoscientificInformation
publication
2008-06-01
Rock mechanics
Temperature
Earthquakes
Clays
NGDC Deposited Data
Citable Data
revision
2022
NERC_DDC
2021-10-25
2022-05-16
creation
2025-05-14
notApplicable
The velocity-step experiments were conducted in a triaxial deformation apparatus in a direct shear slider assembly. In addition to room temperature experiments (23°C), tests were run at controlled experimental temperatures of 60°C, 100°C, 140°C and 180°C (+/-0.4°C). The confining pressure was set using silicon oil at 150 MPa and a pore pressure using deionised water was set at 60 MPa. An axial load was applied using a motor-driven loading column. The initial 2 mm of displacement had a velocity of 0.3 μm/s, then in the ‘velocity-step phase’ the slip velocity was stepped between 3.0 μm/s and 0.3 μm/s every 0.5 mm of slip until the maximum displacement of 5.5 mm was reached.
publication
2011
false
See the referenced specification
publication
2010-12-08
false
See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF
Text File
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Earth, Ocean and Ecological Sciences
University of Liverpool
Herdman Building, 4 Brownlow Street
Liverpool
L69 3GP
originator
Professor in Geology and Geophysics
University of Liverpool
School of Environmental Sciences, 4 Brownlow Street
Liverpool
L69 3GP
originator
University of Liverpool
Jane Herdman Building, 4 Brownlow Street
Liverpool
L69 3GP
originator
British Geological Survey
distributor
British Geological Survey
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British Geological Survey
Environmental Science Centre,Keyworth
NOTTINGHAM
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United Kingdom
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pointOfContact
2025-07-07