Journal of Structural Geology最新文献

筛选
英文 中文
Temperature-dependent frictional properties of opal gouge and their implications for faulting in opaline chert at the Japan Trench subduction zone 日本海沟俯冲带蛋白岩断层的温度相关摩擦特性及其意义
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-11-22 DOI: 10.1016/j.jsg.2025.105589
Kyuichi Kanagawa, Tomoya Nakanishi , Junya Fujimori , Sayumi Sagano , Michiyo Sawai
{"title":"Temperature-dependent frictional properties of opal gouge and their implications for faulting in opaline chert at the Japan Trench subduction zone","authors":"Kyuichi Kanagawa,&nbsp;Tomoya Nakanishi ,&nbsp;Junya Fujimori ,&nbsp;Sayumi Sagano ,&nbsp;Michiyo Sawai","doi":"10.1016/j.jsg.2025.105589","DOIUrl":"10.1016/j.jsg.2025.105589","url":null,"abstract":"<div><div>Recent seismic and ocean-drilling data at the Japan Trench subduction zone suggest that the plate-boundary thrust is located within opaline chert in some places. Because seismogenic faulting along the plate-boundary thrust is known to be temperature-dependent, we investigated temperature-dependent frictional properties of opal gouge and their relevance to faulting in opaline chert at the Japan Trench subduction zone. For this purpose, we conducted triaxial friction experiments on opal gouge at a confining pressure of 150 MPa, a pore-water pressure of 50 MPa, temperatures (<em>T</em>) of 25–200 °C, and axial displacement rates changed stepwise among 0.1, 1 and 10 μm/s.</div><div>Opal gouge showed frictional strength increasing with increasing <em>T</em>, rate-weakening behavior at <em>T</em> ≥ 100 °C, and stick slips at <em>T</em> ≥ 150 °C. When fitted by the rate- and state-dependent friction constitutive law, friction parameter <em>a</em> decreases while friction parameter <em>b</em> significantly increases with increasing <em>T</em> ≥ 100 °C, so that (<em>a</em> – <em>b</em>) value resultantly decreases to negative at <em>T</em> ≥ 100 °C. Microstructures of the opal gouge after the experiments at <em>T</em> ≥ 100 °C suggest the operation of pressure solution during those experiments. Thermally activated pressure solution possibly promoted healing of gouge particles to significantly increase <em>b</em> value with increasing <em>T</em> ≥ 100 °C, thereby decreasing (<em>a</em> – <em>b</em>) value to negative at <em>T</em> ≥ 100 °C. Our experimental results also suggest that seismogenic faulting at the Japan Trench subduction zone possibly occurs at depths where <em>T</em> ≥ 100 °C, provided that the plate boundary thrust is located within opaline chert on the subducting Pacific plate.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105589"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Veining style and size-scaling behavior throughout the generation and exhumation of subduction mélange: Evidence from Japan and Alaska 贯穿于俯冲带形成和发掘的脉纹样式和尺度行为:来自日本和阿拉斯加的证据
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-12-02 DOI: 10.1016/j.jsg.2025.105607
J.N. Hooker , S. Luciano , D.M. Fisher , A.J. Smye , Y. Hashimoto , T. Hosokawa , S.J. Elliott
{"title":"Veining style and size-scaling behavior throughout the generation and exhumation of subduction mélange: Evidence from Japan and Alaska","authors":"J.N. Hooker ,&nbsp;S. Luciano ,&nbsp;D.M. Fisher ,&nbsp;A.J. Smye ,&nbsp;Y. Hashimoto ,&nbsp;T. Hosokawa ,&nbsp;S.J. Elliott","doi":"10.1016/j.jsg.2025.105607","DOIUrl":"10.1016/j.jsg.2025.105607","url":null,"abstract":"<div><div>We document patterns of cemented opening-mode fractures (veins) across the thickness of subduction mélanges, focusing on the Shimanto belt of SW Japan with ancillary observations from the Kodiak accretionary complex, Alaska, USA. We interpret at least two distinct phases of vein formation at seismogenic depths in Cretaceous mélanges of the Shimanto belt. Early veins (Set 1) can be ptygmatically folded, indicating formation prior to the completion of sedimentary compaction. Set 1 is crosscut by pervasive mélange foliation. Cement deposits within Set 1 comprise wall-lining, blocky quartz cement having blue cathodoluminescence (CL) cores and orange rims; calcite generally overgrows quartz, filling fracture pore space left between quartz crystals. Both minerals contain abundant fluid inclusions. Set 1 aperture sizes are power-law distributed, with most strain associated within the largest veins. Late veins (Set 2) crosscut Set 1 and mélange foliations. Set 2 veins have relatively planar walls, crack-seal texture, blue CL, a low density of fluid inclusions, and only sparse overgrowing calcite. Set 2 is numerically dominated by microfractures, likely a consequence of rapid healing at high temperature during fracture opening. Vein intensity is heterogeneous at outcrop and thin-section scales, with veins of both generations preferentially forming within brittle, sand-silt dominated facies, as opposed to intervening shales. Vein and host rock geometries indicate that the mélange deforms by early pure shear that evolves to simple shear as subduction proceeds. Vein formation accommodates plate convergence throughout numerous earthquake cycles on the subduction interface and comprises opening-mode fractures whose formation and cementation reflect long-term, interseismic fluid conditions.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105607"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Thrust ramps, detachments, and fault-related folding kinematics in the South-Central San Joaquin Fold-and-Thrust Belt, California 加州中南部圣华金褶皱冲断带的逆冲斜坡、分离和断层相关的褶皱运动学
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-11-29 DOI: 10.1016/j.jsg.2025.105603
Robert M. Welch , John H. Shaw
{"title":"Thrust ramps, detachments, and fault-related folding kinematics in the South-Central San Joaquin Fold-and-Thrust Belt, California","authors":"Robert M. Welch ,&nbsp;John H. Shaw","doi":"10.1016/j.jsg.2025.105603","DOIUrl":"10.1016/j.jsg.2025.105603","url":null,"abstract":"<div><div>The 1982 (M 5.5) New Idria, 1983 (M 6.5) Coalinga, and 1985 (M 6.1) Kettleman Hills earthquakes demonstrated the activity of blind-thrust ramps in the San Joaquin Fold-and-Thrust Belt, California. However, the potential geometric continuity of these and other faults in the system, including thrust ramps that lie along the strike of the epicentral zones and the underlying basal detachments, remains poorly understood. Previously published cross-sections throughout the region are spatially restricted and have varied in their representation of thrust ramps and detachments. To overcome the limitations of previous studies, we present a new internally consistent regional 3D model of these structures, including fault segments along strike from the 1980s earthquake sequences (Kettleman Middle and South Domes, Lost Hills) and into the San Joaquin Basin. This model is based on an analysis of industry seismic data and coupled with horizon picks from the USGS and CalGEM Oil and Gas Well Data, as well as a relocated seismicity catalog and focal mechanism solutions. Our model reveals that along strike, the system changes from a structural wedge to a composite growth fault-bend fold. Where these structural style changes occur, we observe distinct variations in the eastern extent of deformation in the basin. Specifically, those segments characterized by fault-bend folding send slip into the basin on an upper detachment, which is manifest in both detachment folds and additional thrust ramps. At depth, these fault segments are linked to two major basal detachment levels that extend west beneath the Temblor Ranges.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105603"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
FoldApp: A MATLAB application for area-depth-strain (ADS) analysis of detachment folds FoldApp:用于分离褶皱的面积-深度-应变(ADS)分析的MATLAB应用程序
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-11-29 DOI: 10.1016/j.jsg.2025.105604
Juan Contreras , Ismael Yarbuh , Luis Ángel Vega-Ramírez , Ronald M. Spelz
{"title":"FoldApp: A MATLAB application for area-depth-strain (ADS) analysis of detachment folds","authors":"Juan Contreras ,&nbsp;Ismael Yarbuh ,&nbsp;Luis Ángel Vega-Ramírez ,&nbsp;Ronald M. Spelz","doi":"10.1016/j.jsg.2025.105604","DOIUrl":"10.1016/j.jsg.2025.105604","url":null,"abstract":"<div><div>The Area-Depth-Strain (ADS) method is a mass-balance approach to quantify shortening, depth to detachment, and strain in both contractional and extensional systems We introduce <em>FoldApp</em>, a MATLAB-based, cross-platform app that automates ADS calculations to asses the deformation in detachment folds. The software is organized into three modules that guide users through the necessary steps required by the method: (i) import a seismic interpretation, (ii) set the location of pinning lines in adjacent synclines, (iii) compute the area above the syncline regionals, and (iv) find the best-fit to changes in folded area as a function of stratigraphic thickness. <em>FoldApp</em> also estimates uncertainties in strain and detachment depth, improves reproducibility as users can test the sensitivity of the seismic interpretation to noise, and integrates corrections for shortening caused by tectonic compaction and pure shear layer thickening. Although these effects are rarely considered in mass-balance restorations, they give rise to significant mismatches between the estimated and actual shortening. We tested <em>FoldApp</em> on a representative detachment fold from the Mexican Ridges Fold Belt, western Gulf of Mexico, obtaining robust estimates of tectonic transport, consistent with previously published manual calculations including compaction effects in the transport direction, with quantified uncertainties. <em>FoldApp</em> thus provides a reliable and accessible platform for structural geologists, bridging the gap between traditional interpretation workflows and quantitative analysis.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105604"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A new mode of syn-depositional folding in the Zechstein Supergroup due to differential loading and diagenetically induced density inversion 一种由差异载荷和成岩诱导的密度反转导致的Zechstein超群同沉积褶皱新模式
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-12-03 DOI: 10.1016/j.jsg.2025.105606
Ben Aldridge , Simon Stewart , Dan Phillips , Martino Foschi , Joe Cartwright
{"title":"A new mode of syn-depositional folding in the Zechstein Supergroup due to differential loading and diagenetically induced density inversion","authors":"Ben Aldridge ,&nbsp;Simon Stewart ,&nbsp;Dan Phillips ,&nbsp;Martino Foschi ,&nbsp;Joe Cartwright","doi":"10.1016/j.jsg.2025.105606","DOIUrl":"10.1016/j.jsg.2025.105606","url":null,"abstract":"<div><div>This study examines short-wavelength folding within the Zechstein Supergroup in the Southern Permian Basin by focusing on the Z3 anhydrite (Z3a) stringer, documenting a previously unrecognised mode of deformation that occurred during evaporite deposition in the Late Permian. Three-dimensional mapping of the Z3a reveals a network of irregularly shaped and oriented folds that pre-date Late Palaeocene magmatic intrusions, indicating an early deformation phase (F1) distinct from regional salt tectonics (F2). The observed fold geometries cannot be readily explained by buckling; instead, they are interpreted to result from vertical simple shear driven by differential loading in addition to density increases caused by the diagenetic transformation of gypsum to anhydrite. These density increases influenced deformation most notably across the recently identified basin-scale network of anomalously thick Z3a, causing these sections of the Z3a to sag into the underlying halite units and produce characteristic dome- and bowl-shaped folds without lateral shortening. The stiffness of the Z3a prevented sections from sinking to the base of the Zechstein and preserved early forming structures through the subsequent episode of regional salt tectonics in regions of modest salt structure. Our findings challenge traditional models of intra-salt fold formation that emphasize regional salt tectonics as the primary driver, highlighting the active role that mechanical heterogeneity and diagenesis exert on evaporite deformation. These findings have implications for understanding the mechanical behaviour of layered evaporite sequences for a variety of subsurface applications.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105606"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Controlling factors of the strike-slip fault segmentation: insight from DEM modelling 走滑断层分割的控制因素:来自DEM模拟的洞察
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-11-21 DOI: 10.1016/j.jsg.2025.105586
Liqing Jiao , Yang Jiao , Yueqiao Zhang
{"title":"Controlling factors of the strike-slip fault segmentation: insight from DEM modelling","authors":"Liqing Jiao ,&nbsp;Yang Jiao ,&nbsp;Yueqiao Zhang","doi":"10.1016/j.jsg.2025.105586","DOIUrl":"10.1016/j.jsg.2025.105586","url":null,"abstract":"<div><div>Strike-slip shearing is widespread in the brittle crust and is typically expressed as segmented rupture zones with characteristic spacing. Yet, the key factors controlling this geometric pattern remain poorly understood. In this study, we use discrete element method (DEM) simulations to systematically explore the fundamental physical and tectonic controls on fault segment spacing in strike-slip systems. Our results show that spacing is influenced by both physical and tectonic factors. Physically, spacing increases with crustal thickness and strength, but decreases with density and gravitational acceleration. A near-linear relationship emerges between the ratio of spacing length to thickness and the ratio of strength to the combined effects of density, gravity, and thickness. Tectonically, spacing is reduced by increasing thrust components but enlarged by extensional components. Pre-existing weak zones strongly localize rupture, while surface topography modulates rupture propagation, with segments preferentially forming in lower-elevation areas. These results offer new insights into the mechanics of segmented strike-slip ruptures on Earth and other planetary bodies and provide a framework for better assessing natural hazard risks.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105586"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145624583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Water-induced shear localization and slip mode partitioning in montmorillonite gouge 蒙脱土泥水致剪切局部化及滑移模式分配
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-11-19 DOI: 10.1016/j.jsg.2025.105590
Sangwoo Woo , Raehee Han
{"title":"Water-induced shear localization and slip mode partitioning in montmorillonite gouge","authors":"Sangwoo Woo ,&nbsp;Raehee Han","doi":"10.1016/j.jsg.2025.105590","DOIUrl":"10.1016/j.jsg.2025.105590","url":null,"abstract":"<div><div>Montmorillonite is a clay mineral that commonly occurs in shallow subduction zones and crustal faults and may exhibit a lower frictional strength than other clay minerals when wet. Water in the interlayers can modify the frictional strength of montmorillonite by forming thin water films that lubricate grain contacts and, by reducing effective normal stress under undrained compression where fluid cannot escape. However, little is known about how water affects the development of deformation structures within montmorillonite gouge and slip behavior. We conducted low-velocity shear experiments to explore such aspects using dry powders and wet pastes of Ca-montmorillonite and Na-montmorillonite. The dry powder experiments exhibited high frictional strength, high apparent shear stiffness (or the stiffness reflecting the combined effects of loading frame, forcing blocks, and gouge layers), and stable slip behavior with predominant foliated structures. In contrast, the wet paste experiments showed a lower frictional strength, lower apparent shear stiffness, and unstable stick-slip behavior, with the development of both foliated zones and shear localization zones. The stable slip in the dry powder was possible because the rheological stiffness, or the rate of fault weakening during slip, of the material with foliated zones was negative and thus lower than the apparent shear stiffness. In the wet paste, unstable stick-slip was possible because the shear localization zone had a rheological stiffness higher than the apparent shear stiffness, and stable slip is inferred to have occurred in the foliated zones. Our findings reveal that water in montmorillonite gouges not only significantly lowers the frictional strength but also promotes the formation of shear localization zones as well as foliated zones, eventually leading to the partitioning of slip into different structural zones of montmorillonite-bearing faults. While the velocity-strengthening behavior of a slip zone is generally interpreted as precluding unstable slip, our study provides evidence that this is not necessarily the case, as velocity-weakening and stick-slip events can still occur within slip localization zones, which are parts of the slip zone. This structure-related slip mode partitioning offers a new perspective on conventional fault stability assessments.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105590"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Spatial heterogeneity of burial-related fracture networks controls compartmentalized fluid flow in volcano-sedimentary sequences 埋藏相关裂缝网络的空间非均质性控制着火山-沉积层序的分区流体流动
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-11-17 DOI: 10.1016/j.jsg.2025.105588
Sodam Park , Chae-Eun Park , Namgwon Kim , Hyojong Lee , Seung-Ik Park
{"title":"Spatial heterogeneity of burial-related fracture networks controls compartmentalized fluid flow in volcano-sedimentary sequences","authors":"Sodam Park ,&nbsp;Chae-Eun Park ,&nbsp;Namgwon Kim ,&nbsp;Hyojong Lee ,&nbsp;Seung-Ik Park","doi":"10.1016/j.jsg.2025.105588","DOIUrl":"10.1016/j.jsg.2025.105588","url":null,"abstract":"<div><div>Fracture networks fundamentally control subsurface fluid flow in sedimentary basins, yet the characteristics and controls of burial-related fractures that developed prior to localized tectonic deformation remain poorly understood in sedimentary rocks with marked volcanic input. We investigate fracture network heterogeneity in a Cretaceous volcano-sedimentary sequence from Wi Island, South Korea, which displays negligible tectonic deformation. Through integrated sedimentary petrological analyses and geometrical/topological fracture characterization of outcrop exposures, we demonstrate distinct spatial variations in fracture intensity and permeability anisotropy across different stratigraphic positions. Fracture intensity correlates strongly with lithological parameters, reaching maximum values at lithological boundaries with high brittle mineral content, and showing elevated intensity in areas with high matrix content and cryptocrystalline texture compared to other stratigraphic levels. Calculated permeability characteristics reveal compartmentalized, anisotropic fluid flow patterns that vary with stratigraphic position. These bed-confined fracture networks predominantly provide lateral connectivity within individual layers while maintaining vertical sealing capacity across fine-grained layers, thereby preventing cross-layer fluid migration. This architecture of fracture networks provides critical insights for predicting initial permeability structure in volcano-sedimentary basins before tectonic modification.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105588"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145624582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Dehydroxylation and amorphization of wet serpentinite gouges during experimental seismic slip and implications for coseismic fluid drainage 实验地震滑动过程中湿蛇纹岩沟槽的去羟基化和非晶化及其同震流体排水意义
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-11-22 DOI: 10.1016/j.jsg.2025.105591
Li-Wei Kuo , Wei-Hsin Wu , Matthew S. Tarling , Steven A.F. Smith , Thi Trinh Nguyen , Wen-Jie Wu , Jialiang Si
{"title":"Dehydroxylation and amorphization of wet serpentinite gouges during experimental seismic slip and implications for coseismic fluid drainage","authors":"Li-Wei Kuo ,&nbsp;Wei-Hsin Wu ,&nbsp;Matthew S. Tarling ,&nbsp;Steven A.F. Smith ,&nbsp;Thi Trinh Nguyen ,&nbsp;Wen-Jie Wu ,&nbsp;Jialiang Si","doi":"10.1016/j.jsg.2025.105591","DOIUrl":"10.1016/j.jsg.2025.105591","url":null,"abstract":"<div><div>Dehydroxylation and amorphization of serpentinite occur in natural fault zones and laboratory experiments due to frictional heating during high-velocity slip. Although these processes have been demonstrated under relatively dry experimental conditions, it is unclear whether they are triggered in the presence of water. To address this, we performed rotary-shear friction experiments on water-saturated serpentinite powders at a slip rate of 1 m/s and a normal stress of 10 MPa, in both fluid-drained and undrained conditions. In all experiments, the apparent friction coefficient (i.e., shear stress divided by normal stress) decreased from a peak value of ∼0.32–0.42 to a steady-state value of ∼0.09–0.29. Undrained experiments were associated with gouge compaction, and the temperature measured by a thermocouple in the slip zone reached ∼180 °C by the end of the experiments. Fluid-drained experiments were associated with both gouge compaction and dilation, and the maximum temperature reached ∼635 °C. Using a combination of scanning electron microscopy, focused ion beam transmission electron microscopy, and synchrotron X-ray diffraction analysis, we demonstrate that dehydroxylation and amorphization of serpentinite to form nanocrystalline olivine and enstatite only occurs in fluid-drained conditions. One-dimensional numerical modeling accounting for the main phase changes (water to vapor and serpentine to olivine) shows that the temperature increases rapidly in both the undrained and drained experiments. However, fluid drainage progressively reduces the efficiency of thermal pressurization, leading to increased shear heating and the onset of dehydroxylation and amorphization under fluid-drained conditions. Our results suggest that the distinctive nanocrystalline products of dehydroxylation and amorphization reactions in natural fault zones can only form if fluid drainage occurs away from the slip zone during coseismic slip.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105591"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145624584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Anisotropy of fracture nodes using wavelet analysis 小波分析裂缝节点的各向异性
IF 2.9 2区 地球科学
Journal of Structural Geology Pub Date : 2026-02-01 Epub Date: 2025-11-28 DOI: 10.1016/j.jsg.2025.105602
Pradeep Gairola, Sandeep Bhatt
{"title":"Anisotropy of fracture nodes using wavelet analysis","authors":"Pradeep Gairola,&nbsp;Sandeep Bhatt","doi":"10.1016/j.jsg.2025.105602","DOIUrl":"10.1016/j.jsg.2025.105602","url":null,"abstract":"<div><div>Fracture networks exert a strong influence on rock mechanics, fluid flow, and crustal deformation; however, conventional characterization methods often overlook the spatial anisotropy of fracture nodes. This study introduces a wavelet-based angular variance approach to quantify multiscale anisotropy in fracture network nodes (I, Y, X, X + Y-nodes, and barycenters) using both synthetic and natural datasets. Synthetic tests demonstrate that node populations are spatially random under isotropic conditions but develop distinct directional clustering (cross-shaped NE–SW and NW–SE patterns) under anisotropic configurations. Application to natural datasets reveals node-type–specific anisotropy consistent with structural fabric. In the Jabal Akhdar dataset, X- and X + Y-nodes exhibit strong, statistically significant elongation along ENE–WSW, I-nodes show weak lobation in the same direction, and barycenters remain isotropic. At Getaberget<strong>,</strong> barycenters, Y, X, and X + Y-nodes are significantly anisotropic, trending N–S to NNW and aligning with NE–SW and NW–SE fracture sets. These findings demonstrate that wavelet-based node analysis effectively captures subtle and multiscale anisotropy in fracture systems. The method provides a sensitive, directionally continuous, and scalable framework for quantifying fracture network organization, offering new insights for reservoir characterization, geothermal resource assessment, and fracture-controlled fluid migration in geological systems.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"203 ","pages":"Article 105602"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145624585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信
小红书