Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Evolution of Elastic and Mechanical Properties During Fault Shear: The Roles of Clay Content, Fabric Development, and Porosity

Journal Article · · Journal of Geophysical Research. Solid Earth
DOI:https://doi.org/10.1029/2019jb018612· OSTI ID:1799239
 [1];  [2];  [2];  [2]
  1. Pennsylvania State Univ., University Park, PA (United States); OSTI
  2. Pennsylvania State Univ., University Park, PA (United States)
+ Show Author Affiliations
Phyllosilicates weaken faults due to the formation of shear fabrics. Although the impacts of clay abundance and fabric on frictional strength, sliding stability, and porosity of faults are well studied, their influence on elastic properties is less known, though they are key factors for fault stiffness. We document the role that fabric and consolidation play in elastic properties and show that smectite content is the most important factor determining whether fabric or porosity controls the elastic response of faults. We conducted a suite of shear experiments on synthetic smectite-quartz fault gouges (10–100 wt% smectite) and sediment incoming to the Sumatra subduction zone. We monitored Vp, Vs, friction, porosity, shear and bulk moduli. We find that mechanical and elastic properties for gouges with abundant smectite are almost entirely controlled by fabric formation (decreasing mechanical and elastic properties with shear). Though fabrics control the elastic response of smectite-poor gouges over intermediate shear strains, porosity is the primary control throughout the majority of shearing. Elastic properties vary systematically with smectite content: High smectite gouges have values of Vp ~ 1,300–1,800 m/s, Vs ~ 900–1,100 m/s, K ~ 1–4 GPa, and G ~ 1–2 GPa, and low smectite gouges have values of Vp ~ 2,300–2,500 m/s, Vs ~ 1,200–1,300 m/s, K ~ 5–8 GPa, and G ~ 2.5–3 GPa. We find that, even in smectite-poor gouges, shear fabric also affects stiffness and elastic moduli, implying that while smectite abundance plays a clear role in controlling gouge properties, other fine-grained and platy clay minerals may produce similar behavior through their control on the development of fabrics and thin shear surfaces.
Research Organization:
Pennsylvania State Univ., University Park, PA (United States)
Sponsoring Organization:
USDOE; USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Grant/Contract Number:
EE0006762
OSTI ID:
1799239
Alternate ID(s):
OSTI ID: 1605979
Journal Information:
Journal of Geophysical Research. Solid Earth, Journal Name: Journal of Geophysical Research. Solid Earth Journal Issue: 3 Vol. 125; ISSN 2169-9313
Publisher:
American Geophysical UnionCopyright Statement
Country of Publication:
United States
Language:
English

References (61)

Evolution of elastic wave speed during shear-induced damage and healing within laboratory fault zones: FAULT DAMAGE AND HEALING WITH VP AND VS journal June 2014
Frictional heterogeneities on carbonate-bearing normal faults: Insights from the Monte Maggio Fault, Italy: Complex Friction on Carbonate Faults journal December 2014
San Andreas fault zone velocity structure at SAFOD at core, log, and seismic scales: SAFOD Low-Velocity Zones journal July 2015
Experimental constraints on the relationship between clay abundance, clay fabric, and frictional behavior for the Central Deforming Zone of the San Andreas Fault: CLAY FABRIC AND FRICTION journal October 2016
In situ stress state and strength in mudrocks: STRESS STATE AND STRENGTH IN MUDROCKS journal August 2016
Seismically invisible fault zones: Laboratory insights into imaging faults in anisotropic rocks: Imaging Faults in Anisotropic Rocks journal August 2017
Links between clay transformation and earthquakes along the Costa Rican subduction margin: Clay Transformation and Earthquakes journal August 2017
The Distribution of Dislocations in an Elliptical Glide Zone journal January 1963
Clay gouges in the San Andreas Fault System and their possible implications journal December 1975
Velocity Measurements and Crack Density Determination During Wet Triaxial Experiments on Oshima and Toki Granites journal May 2003
Evolution of ultrasonic velocity and dynamic elastic moduli with shear strain in granular layers journal May 2013
Elastic moduli of a cracked solid journal January 1976
Frictional dependence of gouge mixtures of quartz and montmorillonite on velocity, composition and fabric journal December 1987
Compositional and fluid pressure controls on the state of stress on the Nankai subduction thrust: A weak plate boundary journal September 2003
Comparison of smectite- and illite-rich gouge frictional properties: application to the updip limit of the seismogenic zone along subduction megathrusts journal October 2003
Friction experiments on saturated sediments and their implications for the stress state of the Nankai and Barbados subduction thrusts journal November 2003
On the internal structure and mechanics of large strike-slip fault zones: field observations of the Carboneras fault in southeastern Spain journal June 2003
Ultrasonic wave velocities, gas permeability and porosity in natural and granular rock salt journal January 1998
Internal structure and permeability of major strike-slip fault zones: the Median Tectonic Line in Mie Prefecture, Southwest Japan journal January 2003
Elastic wave velocities and permeability evolution during compaction of Bleurswiller sandstone journal October 2005
The nature and importance of phyllonite development in crustal-scale fault cores: an example from the Median Tectonic Line, Japan journal February 2006
Shear zones in clay-rich fault gouge: A laboratory study of fabric development and evolution journal June 2013
Experimental investigation of incipient shear failure in foliated rock journal August 2015
The Rock Physics Handbook book January 2009
Elasticity of marine sediments: Rock physics modeling journal June 1999
Healing of the shallow fault zone from 1994-1998 After the 1992 M 7.5 Landers, California, Earthquake journal August 2001
Multi-scale compressional wave velocity structure of the San Gregorio Fault zone: SAN GREGORIO FAULT VELOCITY STRUCTURE journal March 2004
Low-velocity damaged structure of the San Andreas Fault at Parkfield from fault zone trapped waves: LOW-VELOCITY DAMAGED STRUCTURE OF THE SAN ANDREAS FAULT journal May 2004
Influence of particle characteristics on granular friction journal January 2005
Effects of pore collapse and grain crushing on ultrasonic velocities and V p / V s journal January 2007
Friction of sheared granular layers: Role of particle dimensionality, surface roughness, and material properties: SHEARED GRANULAR LAYERS journal March 2007
Origin and significance of clay-coated fractures in mudrock fragments of the SAFOD borehole (Parkfield, California) journal January 2006
Effect of hydration state on the frictional properties of montmorillonite-based fault gouge journal January 2007
Clay fabric intensity in natural and artificial fault gouges: Implications for brittle fault zone processes and sedimentary basin clay fabric evolution journal January 2009
Frictional and hydrologic properties of clay-rich fault gouge journal January 2009
Fabric induced weakness of tectonic faults: FABRIC INDUCED WEAKNESS journal February 2010
Effect of clay content and mineralogy on frictional sliding behavior of simulated gouges: Binary and ternary mixtures of quartz, illite, and montmorillonite journal January 2010
The Role of Shear Stress in Fault Healing and Frictional Aging journal December 2018
Frictional State Evolution During Normal Stress Perturbations Probed With Ultrasonic Waves journal June 2019
The Effects of Shear Strain, Fabric, and Porosity Evolution on Elastic and Mechanical Properties of Clay‐Rich Fault Gouge journal November 2019
The apparent friction of granular fault gouge in sheared layers journal January 1994
Comparison of calculated and observed crack densities and seismic velocities in westerly granite journal July 1976
Seismic evidence for overpressured subducted oceanic crust and megathrust fault sealing journal January 2009
Fault zone fabric and fault weakness journal December 2009
Low strength of deep San Andreas fault gouge from SAFOD core journal March 2011
Weakness of the San Andreas Fault revealed by samples from the active fault zone journal February 2011
The determination of the elastic field of an ellipsoidal inclusion, and related problems journal August 1957
Probing the shear-band formation in granular media with sound waves journal May 2012
Ultrasound Propagation in Externally Stressed Granular Media journal March 1999
A higher order approximation to the wave propagation constants for a cracked solid journal October 1986
The Effective Elastic Moduli of Porous Granular Rocks journal December 1981
Postseismic Relaxation Along the San Andreas Fault at Parkfield from Continuous Seismological Observations journal September 2008
Low Coseismic Shear Stress on the Tohoku-Oki Megathrust Determined from Laboratory Experiments journal December 2013
Release of mineral-bound water prior to subduction tied to shallow seismogenic slip off Sumatra journal May 2017
Abundance of smectite and the location of a plate-boundary fault, Barbados accretionary prism journal April 2001
On the relation between fault strength and frictional stability journal January 2011
Frictional properties and sliding stability of the San Andreas fault from deep drill core journal June 2012
Fault rocks and fault mechanisms journal March 1977
Critical porosity: A key to relating physical properties to porosity in rocks journal March 1998
Wave attenuation in partially saturated rocks journal February 1979
Seismic velocities and Poisson’s ratio of shallow unconsolidated sands journal March 2000

Similar Records

The Effects of Shear Strain, Fabric, and Porosity Evolution on Elastic and Mechanical Properties of Clay-Rich Fault Gouge
Journal Article · Thu Oct 31 20:00:00 EDT 2019 · Journal of Geophysical Research. Solid Earth · OSTI ID:1799238

Related Subjects

58 GEOSCIENCES
Geochemistry & Geophysics