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Chris Marone - One of the best experts on this subject based on the ideXlab platform.
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comparison of smectite and illite rich gouge frictional properties application to the updip limit of the seismogenic zone along subduction megathrusts
Earth and Planetary Science Letters, 2003Co-Authors: D. Saffer, Chris MaroneAbstract:Abstract Along plate boundary subduction thrusts, the transformation of smectite to illite within fault gouge at temperatures of ∼150°C is one of the key mineralogical changes thought to control the updip limit of seismicity. If correct, this hypothesis requires illite-rich gouges to exhibit frictionally unstable (velocity-weakening) behavior. Here, we report on laboratory experiments designed to investigate the frictional behavior of natural and synthetic clay-rich gouges. We sheared 5-mm-thick layers of commercially obtained pure Ca-smectite, a suite of smectite–quartz mixtures, and natural illite shale (grain size ranging from 2 to 500 μm) in the double-direct shear geometry to shear strains of ∼7–30 at Room Humidity and temperature. XRD analyses show that the illite shale contains dominantly clay minerals and quartz; within the clay-sized fraction ( 40 MPa). Our data, specifically the velocity-strengthening behavior of illite shale under a wide range of conditions, do not support the hypothesis that the smectite–illite transition is responsible for the seismic–aseismic transition in subduction zones. We suggest that other depth- and temperature-dependent processes, such as cementation, consolidation, and slip localization with increased shearing, may play an important role in changing the frictional properties of subduction zone faults, and that these processes, in addition to clay mineralogy, should be the focus of future investigation.
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Comparison of smectite- and illite-rich gouge frictional properties: Application to the updip limit of the seismogenic zone along subduction megathrusts
Earth and Planetary Science Letters, 2003Co-Authors: D. Saffer, Chris MaroneAbstract:Along plate boundary subduction thrusts, the transformation of smectite to illite within fault gouge at temperatures of ∼150°C is one of the key mineralogical changes thought to control the updip limit of seismicity. If correct, this hypothesis requires illite-rich gouges to exhibit frictionally unstable (velocity-weakening) behavior. Here, we report on laboratory experiments designed to investigate the frictional behavior of natural and synthetic clay-rich gouges. We sheared 5-mm-thick layers of commercially obtained pure Ca-smectite, a suite of smectite-quartz mixtures, and natural illite shale (grain size ranging from 2 to 500 μm) in the double-direct shear geometry to shear strains of ∼7-30 at Room Humidity and temperature. XRD analyses show that the illite shale contains dominantly clay minerals and quartz; within the clay-sized fraction (40 MPa). Our data, specifically the velocity-strengthening behavior of illite shale under a wide range of conditions, do not support the hypothesis that the smectite-illite transition is responsible for the seismic-aseismic transition in subduction zones. We suggest that other depth- and temperature-dependent processes, such as cementation, consolidation, and slip localization with increased shearing, may play an important role in changing the frictional properties of subduction zone faults, and that these processes, in addition to clay mineralogy, should be the focus of future investigation. © 2003 Elsevier B.V. All rights reserved.
D. Saffer - One of the best experts on this subject based on the ideXlab platform.
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comparison of smectite and illite rich gouge frictional properties application to the updip limit of the seismogenic zone along subduction megathrusts
Earth and Planetary Science Letters, 2003Co-Authors: D. Saffer, Chris MaroneAbstract:Abstract Along plate boundary subduction thrusts, the transformation of smectite to illite within fault gouge at temperatures of ∼150°C is one of the key mineralogical changes thought to control the updip limit of seismicity. If correct, this hypothesis requires illite-rich gouges to exhibit frictionally unstable (velocity-weakening) behavior. Here, we report on laboratory experiments designed to investigate the frictional behavior of natural and synthetic clay-rich gouges. We sheared 5-mm-thick layers of commercially obtained pure Ca-smectite, a suite of smectite–quartz mixtures, and natural illite shale (grain size ranging from 2 to 500 μm) in the double-direct shear geometry to shear strains of ∼7–30 at Room Humidity and temperature. XRD analyses show that the illite shale contains dominantly clay minerals and quartz; within the clay-sized fraction ( 40 MPa). Our data, specifically the velocity-strengthening behavior of illite shale under a wide range of conditions, do not support the hypothesis that the smectite–illite transition is responsible for the seismic–aseismic transition in subduction zones. We suggest that other depth- and temperature-dependent processes, such as cementation, consolidation, and slip localization with increased shearing, may play an important role in changing the frictional properties of subduction zone faults, and that these processes, in addition to clay mineralogy, should be the focus of future investigation.
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Comparison of smectite- and illite-rich gouge frictional properties: Application to the updip limit of the seismogenic zone along subduction megathrusts
Earth and Planetary Science Letters, 2003Co-Authors: D. Saffer, Chris MaroneAbstract:Along plate boundary subduction thrusts, the transformation of smectite to illite within fault gouge at temperatures of ∼150°C is one of the key mineralogical changes thought to control the updip limit of seismicity. If correct, this hypothesis requires illite-rich gouges to exhibit frictionally unstable (velocity-weakening) behavior. Here, we report on laboratory experiments designed to investigate the frictional behavior of natural and synthetic clay-rich gouges. We sheared 5-mm-thick layers of commercially obtained pure Ca-smectite, a suite of smectite-quartz mixtures, and natural illite shale (grain size ranging from 2 to 500 μm) in the double-direct shear geometry to shear strains of ∼7-30 at Room Humidity and temperature. XRD analyses show that the illite shale contains dominantly clay minerals and quartz; within the clay-sized fraction (40 MPa). Our data, specifically the velocity-strengthening behavior of illite shale under a wide range of conditions, do not support the hypothesis that the smectite-illite transition is responsible for the seismic-aseismic transition in subduction zones. We suggest that other depth- and temperature-dependent processes, such as cementation, consolidation, and slip localization with increased shearing, may play an important role in changing the frictional properties of subduction zone faults, and that these processes, in addition to clay mineralogy, should be the focus of future investigation. © 2003 Elsevier B.V. All rights reserved.
Takehiro Hirose - One of the best experts on this subject based on the ideXlab platform.
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experiments on smectite-rich gouges
2020Co-Authors: Fabio Ferri, Takehiro Hirose, Giulio Di Toro, Toshihiko ShimamotoAbstract:Thermal pressurization of pore fluid is one of the possible mechanisms responsible for dynamic weakening in landslides and earthquakes, but, to date, has not been reproduced in the laboratory. Here, we report high-velocity experiments performed in a rotary shear friction apparatus on smectite-rich gouges from the 1963 Vaiont landslide (Italy). The gouges were slid under 1 MPa normal stress, for displacements up to 30 m and a slip rate of 1.31 m s )1 under Room-Humidity and watersaturated conditions. Sample dilatancy was observed in RoomHumidity runs after 3‐4 m of slip, concomitant with an increase in normal stress and a decrease in shear stress. Mineralogical and microstructural investigations suggest that dilatancy resulted from expansion of the H2O released by the collapse of the smectite structure due to frictional heating of the slipping zone at T >200 C. We conclude that sample dilatancy is due to thermal pressurization of the clay-rich gouge.
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Experimental investigations on dating the last earthquake event using OSL signals of quartz from fault gouges
Tectonophysics, 2019Co-Authors: Jeong-heon Choi, Takehiro Hirose, Naveen Chauhan, Manami KitamuraAbstract:Abstract Obtaining a reliable age of the latest seismic slip event along an active fault is important for seismic hazard assessment. Here, we observe changes in the optically stimulated luminescence (OSL) signal of quartz crystals due to frictional heating in artificial fault gouges (comprising a mixture of quartz grains and Ca-bentonite powder). The fault gouge was deformed using a high-velocity rotary-shear apparatus at Room temperature and Room Humidity. At a seismic slip rate of 1.31 m·s−1, intense slip localization occurred along a very thin layer (~300 μm thick) within the simulated fault zones (1 mm thick). The estimated temperature of the slip-localized layer (SLL) increased by ~475 °C from frictional heating. The quartz OSL signals of the gouges were fully reset, most noticeably for the SLL. In contrast, there was rare slip-localization at subseismic slip rates (0.06–0.001 m·s−1), for which the estimated temperature rise in the SLL was ~120 °C; hence, the quartz OSL signal was not reset under this condition. The results suggest that quartz OSL dating can be used to constrain the age of the latest seismic event in natural quartz-bearing fault zones where a SLL occurs.
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Frictional melting of clayey gouge during seismic fault slip: Experimental observation and implications
Geophysical Research Letters, 2014Co-Authors: Takehiro Hirose, Gi Young Jeong, Jun-ichi Ando, Hideki MukoyoshiAbstract:Clayey gouges are common in fault slip zones at shallow depths. Thus, the fault zone processes and frictional behaviors of the gouges are critical to understanding seismic slip at these depths. We conducted rotary shear tests on clayey gouge (~41 wt % clay minerals) at a seismic slip rate of 1.3 m/s. Here we report that the gouge was melted at 5 MPa of normal stress and Room Humidity conditions. The initial local melting was followed by melt layer formation. Clay minerals (e.g., smectite and illite) and plagioclase were melted and quenched to glass with numerous vesicles. Both flash heating and bulk temperature increases appear to be responsible for the melting. This observation of clayey gouge melting is comparable to that of natural faults (e.g., Chelungpu fault, Taiwan). Due to heterogeneous fault zone properties (e.g., permeability), frictional melting may be one of the important processes in clayey slip zones at shallow depths.
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Clay–clast aggregates in fault gouge: An unequivocal indicator of seismic faulting at shallow depths?
Journal of Structural Geology, 2012Co-Authors: Raehee Han, Takehiro HiroseAbstract:Abstract A common problem encountered in studies of gouge-bearing natural faults is the difficulty of ascertaining whether the observed gouge was sheared seismically or aseismically; this problem arises because of the scarcity of indicators of fault slip rates for gouge. Recently, clay–clast aggregates (CCAs; a CCA comprises a clastic core mantled by a rim of ultrafine particles) were proposed as a possible indicator of seismic slip in gouge, on the basis of shear experiments on gouge at seismic slip rates. To examine the processes and conditions of CCA formation, we conducted rotary shear experiments on quartz and quartz–bentonite gouges under normal stresses (0.3–3.0 MPa) and slip rates (0.0005–1.3 m s −1 ), and in both Room-Humidity (Room-dry) and water-saturated (wet) conditions. We found that CCAs could be produced in Room-dry gouges even at the lowest slip rates, which are considerably slower than actual seismic slip rates. This finding demonstrates that thermal pressurization and fluidization at elevated temperature during seismic slip are not necessarily needed for the formation of CCAs, contrary to previous views. Given the occurrence of CCAs over a wide range of slip rates, we suggest that the presence of CCAs is not an unequivocal indicator of fault slip at seismic slip rates.
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clay clast aggregates in fault gouge an unequivocal indicator of seismic faulting at shallow depths
Journal of Structural Geology, 2012Co-Authors: Raehee Han, Takehiro HiroseAbstract:Abstract A common problem encountered in studies of gouge-bearing natural faults is the difficulty of ascertaining whether the observed gouge was sheared seismically or aseismically; this problem arises because of the scarcity of indicators of fault slip rates for gouge. Recently, clay–clast aggregates (CCAs; a CCA comprises a clastic core mantled by a rim of ultrafine particles) were proposed as a possible indicator of seismic slip in gouge, on the basis of shear experiments on gouge at seismic slip rates. To examine the processes and conditions of CCA formation, we conducted rotary shear experiments on quartz and quartz–bentonite gouges under normal stresses (0.3–3.0 MPa) and slip rates (0.0005–1.3 m s −1 ), and in both Room-Humidity (Room-dry) and water-saturated (wet) conditions. We found that CCAs could be produced in Room-dry gouges even at the lowest slip rates, which are considerably slower than actual seismic slip rates. This finding demonstrates that thermal pressurization and fluidization at elevated temperature during seismic slip are not necessarily needed for the formation of CCAs, contrary to previous views. Given the occurrence of CCAs over a wide range of slip rates, we suggest that the presence of CCAs is not an unequivocal indicator of fault slip at seismic slip rates.
Giulio Di Toro - One of the best experts on this subject based on the ideXlab platform.
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experiments on smectite-rich gouges
2020Co-Authors: Fabio Ferri, Takehiro Hirose, Giulio Di Toro, Toshihiko ShimamotoAbstract:Thermal pressurization of pore fluid is one of the possible mechanisms responsible for dynamic weakening in landslides and earthquakes, but, to date, has not been reproduced in the laboratory. Here, we report high-velocity experiments performed in a rotary shear friction apparatus on smectite-rich gouges from the 1963 Vaiont landslide (Italy). The gouges were slid under 1 MPa normal stress, for displacements up to 30 m and a slip rate of 1.31 m s )1 under Room-Humidity and watersaturated conditions. Sample dilatancy was observed in RoomHumidity runs after 3‐4 m of slip, concomitant with an increase in normal stress and a decrease in shear stress. Mineralogical and microstructural investigations suggest that dilatancy resulted from expansion of the H2O released by the collapse of the smectite structure due to frictional heating of the slipping zone at T >200 C. We conclude that sample dilatancy is due to thermal pressurization of the clay-rich gouge.
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High velocity friction data and thermochemical modeling data of smectite-rich STx-1b (vacuum dry, Room Humidity and water partly saturated)
2019Co-Authors: Giulio Di Toro, Stefano AretusiniAbstract:The dataset is described also in the readme.txt file as follows: The columns are organized as follows: * Time [milliseconds]: time * Normal [MPa]: normal stress * Slip [m]: equivalent displacement * Vel [m/s]: equivalent tangential velocity * Shear1 [MPa]: shear stress * Mu1 []: friction coefficient = shear stress / normal stress * Thick [mm]: thickness of the gouge layer measured with the low resolution LVDT * Thick_high [mm]: thickness of the gouge layer measured with the high resolution LVDT Models Subfolder \model\ Each filename is the experiment’s name and is in .CSV format. The header for all the tables is in a separate file: header.CSV. The columns are organized as follows: * Time [seconds]: time * U_1 [°C]: temperature in node 1 * U_20 [°C]: temperature in node 20 * Qso [°C/s]: temperature source * Qsi1 [°C/s]: temperature sink of reaction 1 (smectite interlayer dehydration) * Qsi2 [°C/s]: temperature sink of reaction 2 (smectite dehydroxylation) * U2_1 [MPa]: pressure in node 1 * U2_20 [MPa]: pressure in node 20 * Thpress [Pa/s]: pressure source for thermal pressurization * Omega1 [Pa/s]: pressure source for reaction 1 (smectite interlayer dehydration) * Omega2 [Pa/s]: pressure source for reaction 2 (smectite dehydroxylation) * R1_1 []: reacted fraction for reaction 1 (smectite interlayer dehydration) * R2_1 []: reacted fraction for reaction 2 (smectite dehydroxylation)
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Pore fluid in experimental calcite-bearing faults: Abrupt weakening and geochemical signature of co-seismic processes
Earth and Planetary Science Letters, 2013Co-Authors: Marie Violay, D. Cinti, Elena Spagnuolo, Giulio Di Toro, S Nielsen, G Di StefanoAbstract:While it is widely recognized that fluids influence fault strength and earthquake nucleation, propagation and arrest, their effects on co-seismic sliding friction are only conjectured. To shed light on these effects, 55 high velocity (>1ms-1) friction experiments were conducted at Room temperature on Carrara marble samples in the presence of pore fluid (up to 15MPa pore pressure), Room-Humidity and "vacuum" (10-4mbar) conditions. In all the experiments, the friction coefficient evolved from a peak value of 0.6-0.8 to a steady-state value of 0.1 in about 1-1.5m of slip. However, experiments performed in the presence of pore fluid had a large and more abrupt decrease in friction at the initiation of sliding (65% after 20mm of slip), whereas experiments performed under vacuum and Room Humidity conditions showed initial velocity-strengthening behavior followed by a more gradual reduction in friction. This indicates that calcite-bearing rocks are more prone to slip in the presence of water. Under Room-Humidity conditions, CO2 was detected during the entire duration of the experiment. In the presence of pore fluid, HCO3- and Ca2+ were detected for slips >0.1m. The lack of decarbonation products (HCO3- and Ca2+) in pore fluid experiments for slip
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Low- to high-velocity frictional properties of the clay-rich gouges from the slipping zone of the 1963 Vaiont slide, northern Italy
Journal of Geophysical Research, 2011Co-Authors: Fabio Ferri, Takehiro Hirose, Giulio Di Toro, Hiroyuki Noda, Toshihiko Shimamoto, Marino Quaresimin, Nicola De RossiAbstract:The final slip of about 450 m at about 30 m/s of the 1963 Vaiont landslide (Italy) was preceded by >3 year long creeping phase which was localized in centimeter-thick clay-rich layers (60–70% smectites, 20–30% calcite and quartz). Here we investigate the frictional properties of the clay-rich layers under similar deformation conditions as during the landslide: 1–5 MPa normal stress, 2 × 10^(−7) to 1.31 m/s slip rate and displacements up to 34 m. Experiments were performed at Room Humidity and wet conditions with biaxial, torsion and rotary shear apparatus. The clay-rich gouge was velocity-independent to velocity-weakening in both Room Humidity and wet conditions. In Room Humidity experiments, the coefficient of friction decreased from 0.47 at v 0.70 m/s: full lubrication results from the formation of a continuous water film in the gouge. The Vaiont landslide occurred under wet to saturated conditions. The unstable behavior of the landslide is explained by the velocity-weakening behavior of the Vaiont clay-rich gouges. The formation of a continuous film of liquid water in the slipping zone reduced the coefficient of friction to almost zero, even without invoking the activation of thermal pressurization. This explains the extraordinary high velocity achieved by the slide during the final collapse.
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Evidence of thermal pressurization in high-velocity friction experiments on smectite-rich gouges
Terra Nova, 2010Co-Authors: Fabio Ferri, Takehiro Hirose, Giulio Di Toro, Toshihiko ShimamotoAbstract:Terra Nova, 22, 347–353, 2010 Abstract Thermal pressurization of pore fluid is one of the possible mechanisms responsible for dynamic weakening in landslides and earthquakes, but, to date, has not been reproduced in the laboratory. Here, we report high-velocity experiments performed in a rotary shear friction apparatus on smectite-rich gouges from the 1963 Vaiont landslide (Italy). The gouges were slid under 1 MPa normal stress, for displacements up to 30 m and a slip rate of 1.31 m s−1 under Room-Humidity and water-saturated conditions. Sample dilatancy was observed in Room-Humidity runs after ∼3–4 m of slip, concomitant with an increase in normal stress and a decrease in shear stress. Mineralogical and microstructural investigations suggest that dilatancy resulted from expansion of the H2O released by the collapse of the smectite structure due to frictional heating of the slipping zone at T >200 °C. We conclude that sample dilatancy is due to thermal pressurization of the clay-rich gouge.
Richard D. Braatz - One of the best experts on this subject based on the ideXlab platform.
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Tablet coating by injection molding technology – Optimization of coating formulation attributes and coating process parameters
European Journal of Pharmaceutics and Biopharmaceutics, 2018Co-Authors: Parind M. Desai, Vibha Puri, David Brancazio, Bhakti S. Halkude, Jeremy E. Hartman, Aniket V. Wahane, Alexander R. Martinez, Keith D. Jensen, Eranda Harinath, Richard D. BraatzAbstract:We developed and evaluated a solvent-free injection molding (IM) coating technology that could be suitable for continuous manufacturing via incorporation with IM tableting. Coating formulations (coating polymers and plasticizers) were prepared using hot-melt extrusion and screened via stress-strain analysis employing a universal testing machine. Selected coating formulations were studied for their melt flow characteristics. Tablets were coated using a vertical injection molding unit. Process parameters like softening temperature, injection pressure, and cooling temperature played a very important role in IM coating processing. IM coating employing polyethylene oxide (PEO) based formulations required sufficient Room Humidity (>30% RH) to avoid immediate cracks, whereas other formulations were insensitive to the Room Humidity. Tested formulations based on Eudrajit E PO and Kollicoat IR had unsuitable mechanical properties. Three coating formulations based on hydroxypropyl pea starch, PEO 1,000,000 and Opadry had favorable mechanical (
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Tablet coating by injection molding technology - optimization of coating formulation attributes and coating process parameters.
European Journal of Pharmaceutics and Biopharmaceutics, 2017Co-Authors: Parind M. Desai, Vibha Puri, David Brancazio, Bhakti S. Halkude, Aniket V. Wahane, Alexander R. Martinez, Keith D. Jensen, Eranda Harinath, Jeremy Hartman, Richard D. BraatzAbstract:Abstract We developed and evaluated a solvent-free injection molding (IM) coating technology that could be suitable for continuous manufacturing via incorporation with IM tableting. Coating formulations (coating polymers and plasticizers) were prepared using hot-melt extrusion and screened via stress-strain analysis employing a universal testing machine. Selected coating formulations were studied for their melt flow characteristics. Tablets were coated using a vertical injection molding unit. Process parameters like softening temperature, injection pressure, and cooling temperature played a very important role in IM coating processing. IM coating employing polyethylene oxide (PEO) based formulations required sufficient Room Humidity (>30% RH) to avoid immediate cracks, whereas other formulations were insensitive to the Room Humidity. Tested formulations based on Eudrajit E PO and Kollicoat IR had unsuitable mechanical properties. Three coating formulations based on hydroxypropyl pea starch, PEO 1,000,000 and Opadry had favorable mechanical ( 35% elongation, >95 × 10 4 J/m 3 toughness) and melt flow (>0.4 g/min) characteristics, that rendered acceptable IM coats. These three formulations increased the dissolution time by 10, 15 and 35 min, respectively (75% drug release), compared to the uncoated tablets (15 min). Coated tablets stored in several environmental conditions remained stable to cracking for the evaluated 8-week time period.
