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J.D. Byerlee

Publications and source records attributed to J.D. Byerlee.

At least 37 records · Page 2Linked to original sources
USGS1990

Textural development of clayey and quartzofeldspathic fault gouges relative to their sliding behavior

Many of the secondary fault structures developed during triaxial friction experiments have been generally correlated with the structures of natural fault zones. Therefore, any physical differences that can be found between laboratory samples that slide stably and those that show stick-slip motion may help to identify the cause of earthquakes. We have examined petrographically the run products of many triaxial friction experiments using clayey and quartzofeldspathic gouges, which comprise the principal types of natural fault gouge material. The examined samples were tested under a wide range of temperature, confining and fluid pressure, and velocity conditions. The clayey and quartzofeldspathic gouges show some textural differences, owing to their different mineral contents and grain sizes and shapes. In the clayey gouges, for example, a clay mineral fabric and kink band sets are commonly developed, whereas in the quartzofeldspathic gouges fracturing and crushing of the predominately quartz and feldspar grains are important processes. For both types of gouge, however, and whatever the pressure-temperature-velocity conditions of the experiments, the transition from stable sliding to stick-slip motion is correlated with: (i) a change from pervasive deformation of the gouge layer to localized slip in subsidiary shears; and (ii) an increase in the angle betweem the shears that crosscut the gouge layer (Riedel shears) and ones that form along the gouge-rock cylinder boundaries (boundary shears). This suggests that the localization of shear within a fault zone combined with relatively high Riedel-shear angles are somehow connected with earthquakes. Secondary fracture sets similar to Riedel shears have been identified at various scales in major strike-slip faults such as the San Andreas of the western United States (Wallace, 1973) and the Luhuo and Fuyun earthquake faults of China (Deng and Zhang, 1984; Deng et al. , 1986). The San Andreas also contains locked and creeping sections that correspond to the stick-slip and stably sliding experimental samples, respectively. We plan to study the physical structure of the San Andreas fault, to see if the experimentally observed differences related to sliding behavior can also be distinguished in the field.

Physics and Chemistry of the Earth↗
USGS1986

The effects of sliding velocity on the frictional and physical properties of heated fault gouge

The frictional properties of a crushed granite gouge and of gouges rich in montmorillonite, illite, and serpentine minerals have been investigated at temperatures as high as 600??C, confining pressures as high as 2.5 kbar, a pore pressure of 30 bar, and sliding velocities of 4.8 and 4.8??10-2 ??m/sec. The gouges showed nearly identical strength behaviors at the two sliding velocities; all four gouges, however, showed a greater tendency to stick-slip movement and somewhat higher stress drops in the experiments at 4.8??10-2 ??m/sec. Varying the sliding velocity also had an effect on the mineral assemblages and deformation textures developed in the heated gouges. The principal mineralogical difference was that at 400??C and 1 kbar confining pressure a serpentine breakdown reaction occurred in the experiments at 4.8??10-2 ??m/sec but not in those at 4.8 ??m/sec. The textures developed in the gouge layers were in part functions of the gouge type and the temperature, but changes in the sliding velocity affected, among other features, the degree of mineral deformation and the orientation of some fractures. ?? 1986 Birkha??user Verlag.

Pure and Applied Geophysics PAGEOPH↗
USGS1986

Stick slip, charge separation and decay

Measurements of charge separation in rock during stable and unstable deformation give unexpectedly large decay times of 50 sec. Time-domain induced polarization experiments on wet and dry rocks give similar decay times and suggest that the same decay mechanisms operate in the induced polarization response as in the relaxation of charge generated by mechanical deformation. These large decay times are attributed to electrochemical processes in the rocks, and they require low-frequency relative permittivity to be very large, in excess of 105. One consequence of large permittivity, and therefore long decay times, is that a significant portion of any electrical charge generated during an earthquake can persist for tens or hundreds of seconds. As a result, electrical disturbances associated with earthquakes should be observable for these lengths of time rather than for the milliseconds previously suggested. ?? 1986 Birka??user Verlag.

Pure and Applied Geophysics PAGEOPH↗
USGS1986

Changes in complex resistivity during creep in granite

A sample of Westerly granite was deformed under constant stress conditions: a pore pressure of 5 MPa, a confining pressure of 10 MPa, and an axial load of 170 MPa. Pore volume changes were determined by measuring the volume of pore fluid (0.01 M KClaq) injected into the sample. After 6 days of creep, characterized by accelerating volumetric stain, the sample failed along a macroscopic fault. Measurements of complex resistivity over the frequency range 0.001-300 Hz, taken at various times during creep, showed a gradual increase in both conductivity and permittivity. When analysed in terms of standard induced polarization (IP) techniques, the changing complex resistivity resulted in systematic changes in such parameters as percent frequency effect and chargeability. These results suggest that it may be possible to monitor the development of dilatancy in the source region of an impending earthquake through standard IP techniques. ?? 1986 Birka??user Verlag.

Pure and Applied Geophysics PAGEOPH↗
USGS1986

Laboratory measurements of velocity-dependent frictional strength

Water levels, location, depths, and aquifers tapped are given for 113 observation wells in Michigan. Tabulated data include extremes of water levels for 1985 and for the period of record, pumpage of most major groundwater users in the state, and water quality data from selected wells. (USGS)

Open-File Report↗
USGS1985

PERMEABILITY CHANGES IN CRYSTALLINE ROCKS DUE TO TEMPERATURE: EFFECTS OF MINERAL ASSEMBLAGE.

The change in permeability with time of granite, quartzite, anorthosite and gabbro was measured while these rocks were subjected to a temperature gradient. Permeability reductions of up to two orders of magnitude were observed, with the greatest reactions occurring in the quartzite. These changes are thought to be caused by dissolution of minerals at high temperatures, and redeposition of the dissolved material at lower temperatures. Quartz appears to be an important mineral in this self-sealing process. If very low permeability is desired around a nuclear waste repository in crystalline rocks, then a quartz-rich rock may be the most appropriate host.

Conference Paper↗
USGS1983

Chemical reactions accompanying fluid flow through granite held in a temperature gradient

Distilled water was passed at a low rate down a temperature gradient through cylinders of Barre and Westerly Granite. Temperatures ranged from 80–100°C at the outer edges of the cylinders to 250–300°C in central, drilled holes which housed the heating coils. The measured permeabilities of the granite cylinders decreased by as much as two orders of magnitude in experiments of 1–3 weeks' duration. The amount of permeability decrease varied directly with temperature and inversely with the rate of fluid flow. The compositions of the fluids discharged from the granites were functions of temperature and flow rate as well as mineral composition, with dissolved silica concentrations showing trends different from those of the other analyzed species. Fluids from experiments run at higher temperatures but at much lower initial rates of fluid flow had higher concentrations of most ions but substantially lower dissolved silica contents. In contrast, an increase in temperature at similar rates of fluid flow resulted in higher silica concentrations. In the experiments, the distilled water acquired enough dissolved materials at high temperatures to become supersaturated with respect to several minerals at the low-temperature edges of the cylinders. Some of this material, particularly silica, was deposited along grain boundaries and microfractures, causing the observed permeability decreases. The very low rates of fluid flow in some high-temperature experiments significantly increased the rates of SiO 2 precipitation and reduced dissolved silica concentrations relative to other species in the discharged fluids.

Geochimica et Cosmochimica Acta↗
USGS1983

A mechanism to explain the generation of earthquake lights

Explanations of how earthquake lights might arise have failed to show how large charge densities can be concentrated and sustained in a conductive Earth. A physical model is proposed, based on frictional heating of the fault, that solves this and related problems. ?? 1983 Nature Publishing Group.

Nature↗
USGS1978

Velocity anomalies: An alternative explanation based on data from laboratory experiments

Locations and velocities were calculated for microseisms occurring in samples of rock subjected to triaxial loading and injection of pore fluid. This was accomplished by analyzing arrival times of acoustic emission using an automatic first arrival picker. Apparent velocity anomalies were observed prior to both failure of intact samples and violent slip in samples containing saw cuts. Further analysis revealed that these fluctuations in calculated velocity were not due to changes in the true seismie velocity. Instead, variations in calculated velocity are shown to be related to sampling errors in picking first arrivals. The systematic picking of late first arrivals for small magnitude events was found to be a persistent bias resulting in low calculated velocities. This has encouraged the reexamination of earthquake records to determine how important sampling biases are in contributing to reported velocity anomalies. ?? 1978 Birkha??user Verlag.

Pure and Applied Geophysics PAGEOPH↗
USGS1976

A magnetic method for determining the geometry of hydraulic fractures

We propose a method that may be used to determine the spatial orientation of the fracture plane developed during hydraulic fracture. In the method, magnetic particles are injected into the crack with the fracturing fluid so as to generate a sheet of magnetized material. Since the magnetization of a body with extreme dimension ratios, such as a crack, exceeds that of an equidimensional body and since this magnetization is sensitive both to orientation and geometry, this could be used to obtain information about the crack. By measuring the vertical and horizontal components of the magnetic field and field gradients at the earth's surface surrounding the injection well with superconducting magnetometers having 10-4 gamma sensitivity and also by measuring field direction within the well itself, it should be possible to calculate the orientation and perhaps infer the approximate geometry of the fracture surface. Experiments on electric field potential operated in conjunction with this experiment could further constrain estimates of shape and orientation. ?? 1976 Birkha??user Verlag.

Pure and Applied Geophysics PAGEOPH↗