Unfortunately this page does not have a mobile or narrow screen view. Please switch to a desktop computer or increase the size of your browser. For tablets try flipping the screen.

Metadata Files

Data Publication

Mechanical data and microstructures of simulated calcite fault gouge sheared at 550°C

Verberne, Berend Antonie | Chen, Jianye | Pennock, Gillian

GFZ Data Services

(2017)

Descriptions

The largest magnitude earthquakes nucleate at depths near the base of the seismogenic zone, near the transition from velocity weakening frictional slip to velocity strengthening ductile flow. However, the mechanisms controlling this transition, and relevant to earthquake nucleation, remain poorly understood. Here we present data from experiments investigating the effect of slip rate on the mechanical properties and microstructure development of simulated calcite fault gouge sheared at ~550°C, close to the transition from (unstable) velocity weakening to (stable) velocity strengthening behaviour, reported by Verberne et al. (2015). We conducted experiments at a constant effective normal stress (σneff) of 50 MPa, as well as σneff-stepping tests employing 20 MPa ≤ σneff ≤ 140 MPa, at constant sliding velocities (v) of 0.1, 1, 10, or 100 µm/s. Samples sheared at v ≥ 1 µm/s showed a microstructure characterized by a single, 30 to 40 μm wide boundary shear, as well as a linear correlation of shear strength (τ) with σneff. Remarkably, electron backscatter diffraction mapping of polygonal shear band grains demonstrated a crystallographic preferred orientation. By contrast, samples sheared at 0.1 µm/s showed a microstructure characterized by homogeneous deformation and plastic flow, as well as a flattening-off of the τ-σneff curve. Our results point to a strain rate dependent frictional-to-viscous transition in simulated calcite fault gouge, and have important implications for the processes controlling earthquake nucleation at the base of the seismogenic zone.

Keywords


Originally assigned keywords
EPOS
multi-scale laboratories
rock and melt physical properties
European Plate Observing System

MSL enriched keywords
fault rock
fault gouge
minerals
carbonate minerals
calcite
tectonic deformation structure
tectonic fault
Apparatus
deformation testing
shear testing
Measured property
mechanical strength
shear strength
friction - controlled slip rate
rate and state friction (RSF) parameters
friction - controlled stress
slip rate
strain
Inferred deformation behavior
deformation behaviour
frictional deformation
ductile deformation
localized deformation
shear band
Measured property
mechanical strength
shear strength
friction - controlled stress
slip rate
strain
Technique
crystal structure analysis
electron diffraction
electron backscatter diffraction (EBSD)
Analyzed feature
deformation microstructure
brittle microstructure
fault gouge microstructure
Y shear
grain size and configuration
crystallographic preferred orientation (CPO)

MSL enriched sub domains i

rock and melt physics
analogue modelling of geologic processes
microscopy and tomography

Source

https://dataservices.gfz-potsdam.de/panmetaworks/showshort.php?id=escidoc:2638900

Source publisher

GFZ Data Services


DOI

10.5880/fidgeo.2017.012


Creators

Verberne, Berend Antonie

High Pressure & Temperature Laboratory, Utrecht University

ORCID:

https://orcid.org/0000-0002-1208-6193

Chen, Jianye

High Pressure & Temperature Laboratory, Utrecht University

ORCID:

https://orcid.org/0000-0002-5973-5293

Pennock, Gillian

Structural Geology & Tectonics, Utrecht University

ScopusID:

7006507017


Contributors

Verberne, Berend Antonie

ContactPerson

High Pressure & Temperature Laboratory, Utrecht University

ORCID:

https://orcid.org/0000-0002-1208-6193

Chen, Jianye

DataCollector

High Pressure & Temperature Laboratory, Utrecht University

ORCID:

https://orcid.org/0000-0002-5973-5293

Pennock, Gillian

DataCollector

Structural Geology & Tectonics, Utrecht University

ScopusID:

7006507017

Experimental Rock Deformation/HPT-Lab (Utrecht University, The Netherlands)

HostingInstitution

Utrecht University, The Netherlands


References

10.5880/icdp.5052.002

10.1002/2015jb012292

10.1002/2015jb012593

10.1038/s41467-017-01843-3


Citation

Verberne, B. A., Chen, J., & Pennock, G. (2017). Mechanical data and microstructures of simulated calcite fault gouge sheared at 550°C [Data set]. GFZ Data Services. https://doi.org/10.5880/FIDGEO.2017.012


Dates

Created:

2017-10-12

Issued:

2017


Language

en


Rights

CC BY 4.0