Article
Geochemistry & Geophysics
Randolph T. Williams, Christie D. Rowe, Kristina Okamoto, Heather M. Savage, Erin Eves
Summary: This study documents the mechanical and geochemical processes of fault rock development in the shallow San Andreas fault (Mojave segment), highlighting the diverse suite of fault rocks and significant changes in frictional strength caused by the interdependence of these processes. Spatial variations in fault-rock mineralogy and geochemistry indicate marked variations in their relative contribution to fault-rock evolution, suggesting a substantial departure from simple structures envisioned for near-surface seismogenic faults in numerical models is required.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geosciences, Multidisciplinary
Sylvain Barbot
Summary: Establishing a constitutive law for fault friction is crucial for understanding fault behavior, but the complex frictional behavior of natural and synthetic gouges is difficult to explain. This study presents a constitutive framework that explains the rate, state, and temperature dependence of fault friction, and calibrates the model using laboratory data.
Article
Geosciences, Multidisciplinary
Zachary D. Smith, W. Ashley Griffith
Summary: This study investigates the development of off-fault damage through successive tensile loading. The results show that fracture density increases during each earthquake cycle, and pulverized rock can be produced at low strain rates.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
C. E. Seyler, S. Shreedharan, D. M. Saffer, C. Marone
Summary: Frictional healing is essential in understanding the seismic cycle and has an impact on the energy balance, dynamics, and recurrence interval of earthquakes and slow slip events. This study investigates the healing behavior of clay-rich fault gouges and finds that the magnitude and rate of healing decrease with higher clay content. This is due to the alignment of clay grains, which limits the increase in the contact area between grains and hinders the restrengthening process. Clay-rich faults have low healing rates and exhibit rate-neutral to rate-strengthening friction, which may promote frequent small failures or stable sliding.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Hanaya Okuda, Andre R. Niemeijer, Miki Takahashi, Asuka Yamaguchi, Christopher J. J. Spiers
Summary: Experimental results demonstrate that fault surfaces formed by altered basalt exhibit frictionally unstable behavior, which may be the result of alteration of the oceanic crust. These properties help explain the occurrence of large megathrust earthquakes in subduction zones.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Srisharan Shreedharan, David Chas Bolton, Jacques Riviere, Chris Marone
Summary: Laboratory experiments show variations in elastic wave velocity and amplitude prior to earthquakes, primarily controlled by fault slip rate, acceleration, and wallrock stress. Preseismic changes in seismic wave speed may be more common than previously thought, underscoring the importance of continuous and long-term monitoring of crustal faults.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
E. Papachristos, I. Stefanou, J. Sulem
Summary: This study uses discrete elements simulations to investigate the frictional response of fault gouges, considering their previous ultra-cataclastic flow and long-time consolidation loading. The impact of particle characteristics (such as size, polydispersity) and shearing velocities on the gouge's response under seismogenic zone conditions is explored. Monte-Carlo analyses show that local stick-slip events disappear when a large number of numerical samples are averaged. The apparent material frictional response is largely unaffected by the spatial randomness of particles' position and particle size distribution, but is controlled by the mean particle size and the formation of shear bands.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geosciences, Multidisciplinary
Chao Liang, Jean-Paul Ampuero, Daniel Pino Munoz
Summary: This study investigates for the first time the prevalence of supershear ruptures across multiple earthquake cycles on long faults, finding that supershear events only occur in a specific range of friction parameters that are not commonly observed in laboratory experiments, which may explain the rarity of supershear earthquakes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geology
Harold J. Tobin, Demian M. Saffer, David A. Castillo, Takehiro Hirose
Summary: This study successfully constrained the in situ pore pressure and stress state in the deep interior of an accretionary wedge using data from drilling in the Nankai subduction zone. The estimated stress components helped reveal the tectonic stress characteristics in the region, indicating a normal or strike-slip faulting regime with low stress variations.
Article
Geosciences, Multidisciplinary
Lei Wu, Guoqing Chen, Jingfang Xing, Zhiyi Lin
Summary: This paper investigates the brittle cataclastic process of fault rocks, focusing on the structural evolution and mechanical behavior. A large-displacement direct shear model is proposed to simulate the process. The results indicate that the reduction in friction coefficient is caused by the crushing and rounding of rock fragments.
JOURNAL OF STRUCTURAL GEOLOGY
(2022)
Editorial Material
Geochemistry & Geophysics
Ze'ev Reches, Jay Fineberg
Summary: Earthquakes are caused by dynamic fractures due to overstresses, not governed by the frictional properties of faults. Frictional interfaces can sustain a wide range of stresses before sliding, generating stress-fields and rupture dynamics. The values of stresses and energy dissipation are determined by fault frictional properties.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geosciences, Multidisciplinary
Jacek Scibek, Irvine R. Annesley
Summary: Through permeability tests conducted at Gryphon U deposit and fault zone, combined with geological and hydrogeological observations, the study revealed the significant impact of rock porosity and permeability on fluid flow and mineral deposit formation. It was also found that coarse gouges in the fault zone are the most permeable and porous, playing a crucial role in the formation of uranium deposits.
NATURAL RESOURCES RESEARCH
(2021)
Article
Multidisciplinary Sciences
Riddhi Mandal, Semechah K. Y. Lui
Summary: In this study, numerical modelling is performed to investigate the effects of injection volume and rate on fault behavior. The results show that both parameters can affect various aspects of fault behavior to different extents. Aseismic slip plays a significant role in altering the timing of triggered earthquakes and exhibits lasting impacts in subsequent seismic cycles. Increasing injection rate enhances the size of the triggered cluster, while increasing injection volume increases seismicity rate of the sequence. Detailed characterization of earthquake patterns with respect to different injection parameters can provide insights for establishing safe bounds of injection operation and mitigating seismic hazard.
SCIENTIFIC REPORTS
(2022)
Article
Geochemistry & Geophysics
Luca Smeraglia, Simone Fabbi, Andrea Billi, Eugenio Carminati, Gian Paolo Cavinato
Summary: This study provides meso and microstructural observations of hydrocarbon movement along faults and fault zones and reveals the cyclic flow of hydrocarbons within tectonically active faults during seismic cycles. The results indicate the occurrence of pressurized hydrocarbon pulses during coseismic slip and the formation of fault permeability during the seismic phase. The findings contribute to the understanding of the hydraulic behavior of carbonate fault damage zones and have implications for hydrocarbon exploration and production.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
M. Sari, S. Alevizos, T. Poulet, E. Veveakis
Summary: This study extends a suggested model to explain the episodic nature of slow earthquakes, by considering the effects of different faulting mechanisms on chemically induced fluid pressurization and correlating the mechanical response with inclined fault angles. The findings highlight the natural response of shallow dipping faults to exhibit episodic stick-slip instabilities, positioning slow earthquakes and episodic tremor and slip sequences in an intrinsically stable regime.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
M. Takahashi, M. P. A. van den Ende, A. R. Niemeijer, C. J. Spiers
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2017)
Article
Geochemistry & Geophysics
John Townend, Rupert Sutherland, Virginia G. Toy, Mai-Linh Doan, Bernard Celerier, Cecile Massiot, Jamie Coussens, Tamara Jeppson, Lucie Janku-Capova, Lea Remaud, Phaedra Upton, Douglas R. Schmitt, Philippe Pezard, Jack Williams, Michael John Allen, Laura-May Baratin, Nicolas Barth, Leeza Becroft, Carolin M. Boese, Carolyn Boulton, Neil Broderick, Brett Carpenter, Calum J. Chamberlain, Alan Cooper, Ashley Coutts, Simon C. Cox, Lisa Craw, Jennifer D. Eccles, Dan Faulkner, Jason Grieve, Julia Grochowski, Anton Gulley, Arthur Hartog, Gilles Henry, Jamie Howarth, Katrina Jacobs, Naoki Kato, Steven Keys, Martina Kirilova, Yusuke Kometani, Rob Langridge, Weiren Lin, Tim Little, Adrienn Lukacs, Deirdre Mallyon, Elisabetta Mariani, Loren Mathewson, Ben Melosh, Catriona Menzies, Jo Moore, Luis Morales, Hiroshi Mori, Andre Niemeijer, Osamu Nishikawa, Olivier Nitsch, Jehanne Paris, David J. Prior, Katrina Sauer, Martha K. Savage, Anja Schleicher, Norio Shigematsu, Sam Taylor-Offord, Damon Teagle, Harold Tobin, Robert Valdez, Konrad Weaver, Thomas Wiersberg, Martin Zimmer
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2017)
Article
Geosciences, Multidisciplinary
M. P. A. van den Ende, A. R. Niemeijer
GEOPHYSICAL RESEARCH LETTERS
(2018)
Article
Geochemistry & Geophysics
M. P. A. van den Ende, J. Chen, J-P Ampuero, A. R. Niemeijer
Article
Multidisciplinary Sciences
A. R. Niemeijer
SCIENTIFIC REPORTS
(2018)
Article
Geochemistry & Geophysics
M. P. A. van den Ende, G. Marketos, A. R. Niemeijer, C. J. Spiers
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2018)
Article
Geochemistry & Geophysics
Robert Marek Kurzawski, Andre Rik Niemeijer, Michael Stipp, Delphine Charpentier, Jan Hinrich Behrmann, Christopher James Spiers
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2018)
Article
Geochemistry & Geophysics
Luuk B. Hunfeld, Jianye Chen, Andre R. Niemeijer, Christopher J. Spiers
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2019)
Article
Geochemistry & Geophysics
Carolyn Boulton, Andre R. Niemeijer, Christopher J. Hollis, John Townend, Mark D. Raven, Denise K. Kulhanek, Claire L. Shepherd
Article
Geochemistry & Geophysics
Ayumi S. Okamoto, Berend A. Verberne, Andre R. Niemeijer, Miki Takahashi, Ichiko Shimizu, Tadamasa Ueda, Christopher J. Spiers
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2019)
Article
Multidisciplinary Sciences
M. P. A. van den Ende, A. R. Niemeijer
SCIENTIFIC REPORTS
(2019)
Article
Geochemistry & Geophysics
Nina Hellebrekers, Andre R. Niemeijer, Ake Fagereng, Blackwell Manda, Richard L. S. Mvula
Article
Geochemistry & Geophysics
M. P. A. van den Ende, A. R. Niemeijer, C. J. Spiers
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2019)
Article
Geochemistry & Geophysics
Ken-ichi Hirauchi, Yuzuru Yamamoto, Sabine A. M. den Hartog, Andre R. Niemeijer
EARTH AND PLANETARY SCIENCE LETTERS
(2020)
Article
Multidisciplinary Sciences
Peter M. Schutjens, Christopher J. Spiers, Andre Rik Niemeijer
Summary: Intergranular pressure solution plays a crucial role in diagenesis, fault sealing, and healing processes. Experimental observations on quartz aggregates under varying conditions show that different microstructural features are formed based on crystal orientation and stress-induced quartz dissolution kinetics. Further investigation is needed to analyze the mechanism of deformation by pressure solution and the impact of crystallographic control on its kinetics in quartz-rich sands and sandstones.
SCIENTIFIC REPORTS
(2021)
Article
Geochemistry & Geophysics
Lingyu Zhang, Kristoffer Szilas
Summary: This study presents new petrological and geochemical data for the Narssaq Ultramafic Body (NUB) in the Itsaq Gneiss Complex of SW Greenland. The results indicate that the ultramafic rocks of NUB are not mantle residues, but instead represent crustal cumulates derived from high-Mg magmas.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Rong Xu, Sarah Lambart, Oliver Nebel, Ming Li, Zhongjie Bai, Junbo Zhang, Ganglan Zhang, Jianfeng Gao, Hong Zhong, Yongsheng Liu
Summary: This study investigated the iron isotope compositions of Cenozoic basalts in Southeast China, finding significant variations related to different types of basalts and their respective sources.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
C. J. Ebinger, Miriam C. Reiss, Ian Bastow, Mary M. Karanja
Summary: The East African rift system is formed above mantle upwellings and the formation of rifts is related to lithospheric thinning and magmatic activity. The amount of splitting varies spatially and the fast axes are predominantly parallel to the orientation of the rifts. Thick lithospheric modules have less splitting and different orientations, which may indicate mantle plume flow. Splitting rotates and increases in strength as it enters the rift zones, suggesting that the anisotropy is mainly present at shallow depths.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Correction
Geochemistry & Geophysics
Ekaterina Rojas-Kolomiets, Owen Jensen, Michael Bizimis, Gene Yogodzinski, Lukas Ackerman
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Igor S. Puchtel, Ethan F. Baxter
Summary: Oxygen fugacity is a fundamental parameter for understanding redox processes in igneous systems. This study compares the Fe-XANES oxybarometry method with the V-in-olivine method for evaluating fO(2) in MORB lavas. The results show that the V-in-olivine method is not applicable to samples with low MgO content, and that the majority of Archean komatiite sources have lower fO(2) than modern MORB.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Chunfei Chen, Stephen F. Foley, Sebastian Tappe, Huange Ren, Lanping Feng, Yongsheng Liu
Summary: The volatile components CO2 and H2O play a major role in mantle melting and heterogeneity. In this study, Ca isotopes were used to trace the lithological heterogeneity in alkaline magmatic rocks. The results revealed the presence of K-richterite and carbonate components as the source of alkaline magmas with low delta 44/40Ca values. These findings highlight the importance of Ca isotopes as a robust tracer of lithological variation caused by volatiles in the Earth's upper mantle.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Timothee Jautzy, Gilles Rixhon, Regis Braucher, Romain Delunel, Pierre G. Valla, Laurent Schmitt, Aster Team
Summary: Although the current approach to estimate catchment-wide denudation rates using only 10Be concentrations has made significant progress in geomorphology, this study argues for the inclusion of 26Al measurements and testing of steady-state assumptions in slow eroding, formerly glaciated landscapes. The study conducted measurements of both 10Be and 26Al in stream sediments from the Vosges Massif in France and found that elevation, slope, channel steepness, and precipitation were the primary factors controlling denudation rates. The study also revealed a significant relationship between the extent of past glaciation and the cosmogenic (un-)steadiness in the stream sediments.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Erik van der Wiel, Douwe J. J. van Hinsbergen, Cedric Thieulot, Wim Spakman
Summary: Numerical models of Earth's mantle dynamics can predict the vigour and mixing of mantle flow, and the average slab sinking rates are an unexplored parameter that can provide intrinsic information on these characteristics. Through numerical experiments, it has been found that slab sinking rates are strongly correlated with mantle convection and mixing, and may explain geochemical observations from hotspot volcanoes.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)