Article
Multidisciplinary Sciences
Pathikrit Bhattacharya, Allan M. Rubin, Terry E. Tullis, Nicholas M. Beeler, Keishi Okazaki
Summary: A study found that frictional strengthening is primarily slip-dependent rather than solely dependent on time-dependent increase in contact area. This has important implications for the development of constitutive models for friction.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Energy & Fuels
C. Okay Aksoy, Guzin Gulsev Uyar Aksoy, H. Eray Yaman
Summary: The elasticity modulus of rock material (E-i) is a parameter that varies under different stresses, while the deformation modulus of rock mass (E-m) is a parameter used in the design of rock structures. The E-m value is affected by rock mass characteristics and the properties of the rock material. Currently, designs are made using fixed E-i and E-m values, but this study proposes a new method that considers the stress conditions and uses a time-stress-deformation-strength function to calculate variable E-i values. Numerical modeling analyses were conducted to compare the results of this new method with the classical method, leading to important findings.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Geochemistry & Geophysics
G. Pozzi, C. Collettini, M. M. Scuderi, T. Tesei, C. Marone, A. Amodio, M. Cocco
Summary: Magnetite-rich serpentinites, found in low-strain domains of shear zones, have the potential to nucleate unstable slip and induce earthquakes, especially at low slip velocities. Through laboratory experiments, we demonstrate that these rocks display strong sensitivity to loading rate and undergo two deformation mechanisms depending on mineralogical composition and structure, leading to stable and unstable slip.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Engineering, Geological
Rong Zhao, Chunguang Li
Summary: This study presents a new relation model to describe the simultaneous dependence of dilation angle on the internal variable and the minimum principal stress for rocks. The model has been validated and shows good agreement with experimental results.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Rishav Mallick, Aron J. Meltzner, Louisa L. H. Tsang, Eric O. Lindsey, Lujia Feng, Emma M. Hill
Summary: A 32-year-long slow-slip event occurred on a shallow part of the Sunda megathrust, perhaps because of stress accumulation after fluid expulsion, according to an analysis of the deformation history of the area and physics-based simulations. This study highlights the potential for missing or mis-modelling these transient phenomena globally and provides a method for detecting slow-slip events that could substantially revise earthquake and tsunami hazard and risk assessments for populations living near fault lines.
Article
Engineering, Geological
Sabrina C. Y. Ip, Ronaldo I. Borja
Summary: The mechanical properties of clay rocks evolve with the degree of saturation, leading to changes in stiffness and strength anisotropy. Numerical models that capture the evolving elastic and plastic anisotropy with saturation are required for accurate predictions. The study presents an anisotropy framework for coupled solid deformation-fluid flow in unsaturated elastoplastic media, demonstrating the role of evolving stiffness and strength anisotropy in the mechanical behavior of clay rocks.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2022)
Article
Geochemistry & Geophysics
Benjamin D. Belzer, Melodie E. French
Summary: Chlorite, a phyllosilicate mineral, was studied to understand its role in fault slip. The experiments revealed that its frictional strength increases with temperature and transitions from rate-strengthening to rate-weakening behavior. The results suggest that the rate-weakening behavior is controlled by time-dependent properties of water adsorbed to mineral surfaces.
Review
Energy & Fuels
Usama Alameedy, Ahmed Fatah, Ahmed K. Abbas, Ahmed Al-Yaseri
Summary: Acid treatment is widely used in the petroleum industry to stimulate carbonate formations. However, the generated wormholes can cause degradation in the mechanical properties of rocks, which is a key issue. Therefore, careful monitoring of the acidizing procedure and post-treatment evaluation of the rocks are crucial for matrix acidizing.
Article
Engineering, Geological
Gamil M. S. Abdullah, Ahmed Abd El Aal, Ahmed E. Radwan, Talha Qadri, Nevin Aly
Summary: The slake durability of carbonate rocks, influenced by mineralogical composition and strength, was tested through drying and wetting cycles. Results showed significant loss in mechanical properties after four cycles, especially in unconfined compressive strength (UCS). The study highlights the importance of understanding and accurately calculating the degradation behavior of carbonate rocks for engineering applications, and suggests further research into the effect of slaking fluid on limestone durability.
Article
Engineering, Geological
Sabrina C. Y. Ip, Ronaldo I. I. Borja
Summary: The microstructure of clay rocks is anisotropic, and the interactions between anisotropy at different scales can give rise to emerging properties. This study develops a homogenization model to capture the multiscale interactions of elastic anisotropy in unsaturated clay rocks. The model provides a quantitative link between anisotropy at multiple scales in clay rocks and its macroscopic anisotropic stiffness.
Article
Geochemistry & Geophysics
Yanbin He, J. German Rubino, Santiago G. Solazzi, Nicolas D. Barbosa, Marco Favino, Tianning Chen, Jinghuai Gao, Klaus Holliger
Summary: We propose a novel coupled fluid-poroelastic model and numerical upscaling procedure to calculate seismic attenuation and velocity dispersion in porous rocks induced by fluid pressure diffusion in the presence of mesoscopic fluid-saturated voids. The proposed approach shows advantages over purely poroelastic models in modeling fluid-saturated mesoscopic voids, and allows for the effects of different types of fluid pressure diffusion in the seismic characteristics of synthetic samples.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Engineering, Geological
Xuhai Tang, Jingjing Xu, Yiheng Zhang, Haifeng Zhao, Adriana Paluszny, Xue Wan, Zhengzhi Wang
Summary: In the future, geotechnical engineering will be essential for human activities in space, such as asteroid mining. However, obtaining rock samples for testing from space missions is challenging due to their rarity and irregular shapes. Microscale Rock Mechanics Experiments (micro-RME) are being used to determine the macroscale Young's modulus of these samples. This study compared different upscaling methods and found that the Accurate Grain-Based Model (AGBM) was the most accurate. The AGBM was then used to estimate the mechanical properties and macroscale Young's modulus of a specific asteroid meteorite.
ENGINEERING GEOLOGY
(2023)
Article
Engineering, Geological
Xiangsheng Chen, Yinping Li, Lihong Tong, Daxin Geng, Zhikai Dong, Peiliang Yang
Summary: Experimental results suggest that the deformation and strength of rocks are heavily influenced by the damage suffered during loading. Traditional constitutive models fail to accurately describe the non-linear deformation behaviors of rocks. To address this limitation, a new elastoplastic damage constitutive model is proposed, taking into account the competition between damage and strain hardening or softening during rock compression. The model is validated through finite element programming and triaxial compression tests. Comparison with experimental data shows that the model effectively captures the stress-strain curves and damage-strain curves of rocks, particularly the phenomenon of softening, hardening, and residual strength. Parametric analysis reveals the impact of confining pressure, scale parameter, and shape parameter on rock damage. The results demonstrate that rock properties significantly affect strength and deformation, which are closely tied to stress-induced damage and strain characteristics.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Geochemistry & Geophysics
Markus Ohl, Billy Nzogang, Alexandre Mussi, David Wallis, Martyn Drury, Oliver Plumper
Summary: The study investigates the deformation mechanisms active in carbonate fault zones in Greece, finding evidence for both frictional failure and viscous mechanisms during seismic deformation of carbonates. The research suggests that repeated introduction of plastic strain and recrystallization can lead to the formation of a cohesive nanogranular material with grain-boundary strengthening effect, observed over 6 orders of magnitude. The study's findings imply cyclic repetition of deformation and annealing processes in the fault rocks.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Energy & Fuels
Yu Fan, Huan Peng, Gang Chen, Junliang Peng, Huifen Han, Yi Qin, Liang Wang, Dan Liu
Summary: The carbonate gas reservoirs in the Sichuan Basin require stimulation. In this study, a rotary disc instrument was used to investigate the acid-rock reaction rate under various conditions. The results showed that conventional acid had the fastest reaction rate.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Geochemistry & Geophysics
R. Ruggieri, M. M. Scuderi, F. Trippetta, E. Tinti, M. Brignoli, S. Mantica, S. Petroselli, L. Osculati, G. Volonte, C. Collettini
Summary: The presence of weak phyllosilicates in mature carbonate fault zones can significantly affect frictional strength, stability, and healing, especially under wet conditions. An increase in shale content leads to a reduction in frictional strength and a transition from velocity-weakening to velocity-strengthening behavior.
Article
Geochemistry & Geophysics
Piercarlo Giacomel, Roberta Ruggieri, Marco M. Scuderi, Elena Spagnuolo, Giulio Di Toro, Cristiano Collettini
Summary: The study investigates the frictional properties of unaltered basalts under various conditions, highlighting the significant impact of microstructural heterogeneities on friction velocity dependence. Results suggest that friction instabilities may promptly nucleate in shear zones within basaltic gouge layers, whereas joint surfaces characterized by rough rock-on-rock contacts are less prone to unstable slip.
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
Multidisciplinary Sciences
Cristiano Collettini, Telemaco Tesei, Fabio Trippetta, Marco M. Scuderi, Eliza Richardson, Chris Marone, Giacomo Pozzi, Cecilia Viti
Summary: Experimental studies on rock deformation have shown that solid samples with well-developed foliation exhibit lower friction compared to powdered equivalents, with sliding along phyllosilicate-rich foliation surfaces being the primary reason for reduced friction. Additionally, micro-and nano-structural analyses reveal that high friction in powdered rocks is due to fracturing, grain rotation, translation, and associated dilation, highlighting the importance of foliation in influencing the frictional properties of faults.
JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
(2021)
Article
Geochemistry & Geophysics
G. Volpe, G. Pozzi, E. Carminati, M. R. Barchi, M. M. Scuderi, E. Tinti, L. Aldega, C. Marone, C. Collettini
Summary: Crustal seismicity usually occurs within the seismogenic layer, which is typically below 10 km depth, and its lower boundary is influenced by the properties of the sedimentary cover and rock. Studies in the central-northern Apennines have shown that seismic sequences primarily occur within the sedimentary cover, indicating the significant role of the basement in dictating the depth of the seismogenic zone.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Marco M. Scuderi, Brett M. Carpenter
Summary: Observations of slow earthquakes and tremor have raised fundamental questions about the physics of quasi-dynamic rupture and the underlying fault zone processes. The presence of serpentinite suggests its important role in controlling complex fault slip behavior. Experimental results show the frictional behavior of serpentinite sampled from different locations, and highlight the significant influence of mineralogy on frictional stability and hydrological properties.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Giacomo Pozzi, Marco M. Scuderi, Elisa Tinti, Manuela Nazzari, Cristiano Collettini
Summary: Fault stability is closely related to the frictional and healing properties of fault rocks and associated fabrics. The reactivation and slip behavior of dolomite-anhydrite analog faults are controlled by fault fabrics. The study reveals that changes in normal stress can result in different fault behaviors, such as large stress drops and high slip velocities, or low stress drops and slow stick-slip events. The integration of microstructural and mechanical data suggests that frictional and chemically assisted healing processes play a relevant role in developing large instabilities in natural faults. Additionally, fault rock heterogeneity modulates the slip velocity function and the dynamics of repeating stick-slip cycles.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Multidisciplinary Sciences
C. Collettini, M. R. Barchi, N. De Paola, F. Trippetta, E. Tinti
Summary: Analysis of the 2016-2017 Central Italy seismic sequence reveals that seismic activity not only occurs along major fault structures, but also within volumes of Triassic Evaporites with a different frequency-magnitude distribution. The study suggests that ductile crustal deformation can cause distributed microseismicity.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Nico Bigaroni, Marco Maria Scuderi, Frederic Cappa, Yves Guglielmi, Christophe Nussbaum, Luca Aldega, Giacomo Pozzi, Cristiano Collettini
Summary: The Opalinus Clay is an important potential sealing horizon for radioactive waste repositories and carbon storage. Laboratory experiments show that relative humidity, grain size, and normal stress affect the frictional properties and stability of fault analogues. Increasing humidity decreases the friction coefficient and increases the stability parameter, while increasing normal stress leads to a transition from localized to distributed deformation.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Corentin Noel, Carolina Giorgetti, Marco M. Scuderi, Cristiano Collettini, Chris Marone
Summary: Fault stability is influenced by fault zone width, structural complexity, fault rock wear rate, and the presence of gouge during frictional sliding. Shear displacement plays a key role in the transition from stable to unstable sliding, and strain localization is an important factor controlling fault stability. The rate-and-state parameters (a-b) and D-c are affected by shear displacement and wear rate, with enhanced velocity weakening and potential instability observed for larger fault slip.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
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)
