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.

Date (Creation): 2025-05-14

Citation identifier: http://data.bgs.ac.uk/id/dataHolding/13608414

Point of contact

Organisation name	Individual name	Electronic mail address	Role
University of Liverpool	Dr Elisabetta Mariani	not available	Originator
University of Liverpool	Professor Daniel Faulkner	not available	Originator
University of Liverpool	Isabel Ashman	not available	Originator
British Geological Survey	Enquiries	not available	Distributor
British Geological Survey	Enquiries	not available	Point of contact

Maintenance and update frequency: notApplicable

GEMET - INSPIRE themes, version 1.0

Geology

BGS Thesaurus of Geosciences

Rock mechanics
Temperature
Earthquakes
Clays
NGDC Deposited Data
Citable Data

dataCentre

Keywords

NERC_DDC

Access constraints: Other restrictions

Other constraints: licenceOGL

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Use constraints: Other restrictions

Other constraints: The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Language: English

Topic category

Geoscientific information

Begin date: 2021-10-25

End date: 2022-05-16

Reference System Information

No information provided.

Distribution format

Name	Version
Text File

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	not available	Distributor

OnLine resource

Protocol	Linkage	Name
	https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item188220	Data

OnLine resource

Protocol	Linkage	Name
	https://doi.org/10.5285/7337c4aa-4fe5-4c8f-abe6-75deb0701e03	Digital Object Identifier (DOI)

Hierarchy level: Non geographic dataset

Other: non geographic dataset

Conformance result

Title: INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology

Date (Publication): 2011

Explanation: See the referenced specification

Pass: No

Conformance result

Title: Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

Date (Publication): 2010-12-08

Explanation: See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Pass: No

Statement: 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.