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
MSL enriched keywords
Metadata
MSL enriched sub domains
Source
Source publisher
| GFZ Data Services |
DOI
| 10.5880/fidgeo.2017.012 |
Creators
| Verberne, Berend Antonie |
| Personal |
| High Pressure & Temperature Laboratory, Utrecht University |
| Chen, Jianye |
| Personal |
| High Pressure & Temperature Laboratory, Utrecht University |
| Pennock, Gillian |
| Personal |
| Structural Geology & Tectonics, Utrecht University |
Contributors
| Verberne, Berend Antonie |
| Personal |
| High Pressure & Temperature Laboratory, Utrecht University |
| Chen, Jianye |
| Personal |
| High Pressure & Temperature Laboratory, Utrecht University |
| Pennock, Gillian |
| Personal |
| Structural Geology & Tectonics, Utrecht University |
| Experimental Rock Deformation/HPT-Lab (Utrecht University, The Netherlands) |
| Personal |
| Utrecht University, The Netherlands |
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
References
Dates
| Created | 2017-10-12 |
| Issued | 2017 |
Language
en
Rights
| Name | CC BY 4.0 |
| URI | http://creativecommons.org/licenses/by/4.0 |
Locations
- no geo-locations found -