Tectonophysics最新文献

{"title":"Along-strike variations in oceanic crustal deformation along the Central Basin Fault, West Philippine Basin","authors":"Jingyan Zhao ,&nbsp;Yanghui Zhao ,&nbsp;Jiangyang Zhang","doi":"10.1016/j.tecto.2025.230787","DOIUrl":"10.1016/j.tecto.2025.230787","url":null,"abstract":"<div><div>Rifting of pre-existing oceanic lithosphere in subduction systems plays a crucial role in understanding oceanic crust formation, yet it remains inadequately studied. The Central Basin Fault (CBF) in the West Philippine Basin (WPB), a hyper-extensional center that developed subsequent to the primary seafloor spreading phase, offers an exceptional setting for investigating oceanic rifting processes. Utilizing published gravity and seismic data and an integrated approach combining 3D Moho inversion and 2D crustal structure modeling, we elucidate significant along-strike variations within the CBF. Our analysis reveals a striking transition in fault pattern and magmatic activity: from symmetric, magma-rich extension in the western segment, through a central segment of minimal deformation, to asymmetric, magma-poor extension in the eastern segment. Notably, the eastern termination exhibits ultra-thinned crust and potential serpentinized mantle exhumation, indicative of localized intense deformation during the final stages of extension. Integrating our results with previous volcanic ages, we propose that the CBF originated from intensive deformation associated with Kyushu-Palau Ridge (KPR) rifting. This comprehensive study reveals a scenario of intensive deformation preceding the cessation of seafloor spreading, where pre-existing lithospheric fabric, regional tectonic forces, and localized magmatism strongly influence deformation patterns. Our findings provide novel insights into oceanic crustal evolution beyond the primary spreading stage, elucidating the complex processes shaping oceanic lithosphere within a subduction system context.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"909 ","pages":"Article 230787"},"PeriodicalIF":2.7,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Azimuthally anisotropic Rayleigh-wave phase-velocity maps of Europe","authors":"Chiara Civiero ,&nbsp;Raffaele Bonadio ,&nbsp;Antonio Villaseñor","doi":"10.1016/j.tecto.2025.230788","DOIUrl":"10.1016/j.tecto.2025.230788","url":null,"abstract":"<div><div>The European lithosphere is highly heterogeneous, with significant velocity contrasts across the continent. Despite its complexity, much of its detailed structure remains unexplored. We present azimuthally anisotropic phase-velocity maps of Rayleigh waves in the period range 4–40 s for Europe, derived from two years (2011−2012) of continuous waveform data from the Virtual European Broadband Seismic Network (VEBSN) and various temporary arrays. Using ambient-noise cross-correlation, we compute two-station dispersion measurements and integrate them into a tomographic inversion, simultaneously solving for isotropic and anisotropic structures through a least-squares approach. Our thorough suite of tests optimizes regularization and evaluates the resolution and trade-offs between isotropic and anisotropic anomalies. The phase-velocity maps at shorter periods reveal detailed images of major sedimentary basins, with the lowest velocities detected beneath the North German Basin, North Sea Basin, Rhone Basin, Po Plain, Pannonian Basin, and the Bay of Biscay. At longer periods, low-velocity anomalies are prominent beneath the Alps, Northern Apennines, Dinarides, and Anatolian Peninsula. Azimuthal anisotropy is also mapped in the shallow lithosphere, with fast axes in Southern Europe aligned parallel to mountain ranges such as the Pyrenees and Alpine-Apennine system. In Central Europe, the Tornquist-Teisseyre suture zone marks a transition between two domains of different anisotropic structures, suggesting “frozen-in” fabrics originated before the continental collision. The level of detail of these new phase-velocity maps makes them suitable for joint inversion with different types of geophysical data and as starting models for other imaging methods such as full-waveform inversion.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"909 ","pages":"Article 230788"},"PeriodicalIF":2.7,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraining frictional stability-permeability evolution in rock fractures: A comparative study between granite and shale","authors":"Juan Zhang ,&nbsp;Yunzhong Jia ,&nbsp;Jiren Tang ,&nbsp;Yiyu Lu ,&nbsp;Yong Liu","doi":"10.1016/j.tecto.2025.230776","DOIUrl":"10.1016/j.tecto.2025.230776","url":null,"abstract":"<div><div>Large-scale fluid injection during hydraulic fracturing may cause seismic activity during deep geothermal and shale gas development. Constraining the relationship between frictional stability and permeability evolution of fractures is critical since it may provide an indicator to predict frictional behaviors based on monitoring hydraulic evolution. However, the relationship between frictional stability and permeability evolution is poorly understood, especially for different rocks. Hence, we conducted a series of velocity-stepping experiments to explore the shear slip stability of granite and shale fractures, the principal rocks for geothermal and shale gas reservoirs. The results indicate that with the increase of effective normal stress, the permeability and frictional stability <em>(a-b)</em> of both shale and granite fractures decrease. Shale exhibits a velocity-strengthening behavior, while granite exhibits a velocity-weakening behavior when a slip velocity change occurs. By calculating the permeability response parameters (Δ<em>k</em>/<em>k</em>_trans), the results show that with the increase of fracture permeability, the possibility of seismicity induced by fluid injection increases, which provides an indicator as an early warning for potentially damaging seismic events. The experimental results of the permeability test also show that the fracture permeability increases slightly after the short slip. In contrast, the long-term slip will inevitably cause a further decrease in the permeability. This study improves our understanding of fracture permeability and slip stability.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"909 ","pages":"Article 230776"},"PeriodicalIF":2.7,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143946682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic stratigraphic framework, dispersal of depocenters, and helium reservoirs in the Rukwa Rift Basin, Tanzania","authors":"Ernest Mulaya ,&nbsp;Jon Gluyas ,&nbsp;Ken McCaffrey ,&nbsp;Thomas Phillips ,&nbsp;Chris Ballentine","doi":"10.1016/j.tecto.2025.230786","DOIUrl":"10.1016/j.tecto.2025.230786","url":null,"abstract":"<div><div>The Rukwa Rift Basin (RRB) in the southwestern Tanzania presents favourable geological conditions for the occurrence and accumulation of helium gas. However, the evolution and dynamics of these favourable conditions in relation to helium remain complex. In this study, laboratory- cored samples, 2D seismic reflection data, Digital Elevation Model (DEM) and well data are integrated to map the distribution of sediment accumulation and potential helium reservoirs. The isochron and time-thickness maps unveil that the RRB experienced a shift in depocenter location and progressive strata dispersal in space and time during each of the rifting phases from the late Paleozoic to the late Cenozoic. The results reveal a change in morphology while distribution of depocenters is defined by topographic highs related to footwall uplift during a multiphase rifting history that modulated the deposition, differential erosional patterns, drainage system and sediment routing in the RRB. The depocenters to the south of the Saza shear zone might have been isolated initially during Karoo rifting, contiguous during Cretaceous and linked into a single main depocenter during the latter stages of rifting between late Miocene and Pleistocene. Petrophysical analysis reveal high porosity and permeability ranges, that is ∼26–30 % and ∼ 272.7–660.6 mD respectively. These petrophysical parameters are high enough for potential helium reservoirs comprising sandstone sequences mainly in the Karoo and Red Sandstone formations.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"909 ","pages":"Article 230786"},"PeriodicalIF":2.7,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravity deep structure and dynamics of Yishu fault zone revealed by land-sea gravity observation","authors":"Houpu Li ,&nbsp;Qipei Pang ,&nbsp;Yunlong Wu ,&nbsp;Yi Zhang ,&nbsp;Hao Li ,&nbsp;Fan Zhang ,&nbsp;Shaofeng Bian ,&nbsp;Zhouyi Kang","doi":"10.1016/j.tecto.2025.230778","DOIUrl":"10.1016/j.tecto.2025.230778","url":null,"abstract":"<div><div>The Yishu fault zone is the main part of the Tanlu fault zone, located between the Luxi Uplift, Jiaonan Uplift, and the Sulu Orogen. The tectonic environment is highly complex in this region, where the seismic activities are the most intense within the Tanlu fault zone. Studying the distribution of crustal thickness and density structure in this region is of significant practical importance for understanding the seismic mechanisms in the Yishu fault zone. Based on measured gravity data, we utilized regional gravity isostatic analysis and crustal density structure inversion methods to explore and analyze the deep structural characteristics and dynamic significance of the Yishu fault zone and its adjacent areas. The results indicate that the Yishu fault zone, as a lithospheric-scale tectonic boundary, exhibits different gravity anomaly distribution characteristics across the various blocks in the study area. The northern part of this fault zone is in an unbalanced state, exhibiting more frequent tectonic activity. The Xuhuai block and Jiaonan Uplift at the southern end of the Luxi Uplift demonstrate an upward uplift trend. A widespread distribution of high-density anomalies is observed in the lower crust beneath the Yishu fault zone and the Luxi Uplift, likely due to the upwelling of high-density materials from the upper mantle, which causes crustal compression and uplift. It may also reflect the metamorphic rocks formed by high-temperature and high-pressure metamorphism in the deep crust of the Yishu fault zone. Furthermore, earthquakes in the study area are frequently concentrated in the crustal density transition zone and regions where faults intersect. The intersection of the Yishu fault zone with the Mengshan front fault and the Cangni fault creates a deep seismogenic environment with moderate to strong earthquakes.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"909 ","pages":"Article 230778"},"PeriodicalIF":2.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetotelluric imaging of the Parnaíba Basin: Implications to the West Gondwana formation","authors":"Gonzalo Romero-Beltran ,&nbsp;Emanuele F. La Terra ,&nbsp;Liliane P. Panetto ,&nbsp;Hoël Seillé","doi":"10.1016/j.tecto.2025.230777","DOIUrl":"10.1016/j.tecto.2025.230777","url":null,"abstract":"<div><div>The Parnaíba Basin, in northeastern Brazil, is one of the most significant intracratonic basins on the South American platform. Its formation, driven by vertical thermal and mechanical processes has been extensively studied, however, the internal structural configuration remains subject of debate. Magnetotellurics (MT) is a geophysical method that provides information about the geo-electric internal distribution. As part of the multi-physics Parnaíba Basin Analysis Project (PBAP), 218 broadband and 37 long-period MT stations were deployed along an <em>E</em>-W transect profile of <span><math><mo>∼</mo><mn>1400</mn><mspace></mspace><mi>km</mi></math></span>. The MT data were inverted to produce 3-D resistivity models. Lateral resistivity variations were identified along the profile and interpreted as the amalgamation of the three blocks, from west to east: Amazonian Craton, Parnaíba block, and Borborema Province. Within each block, the models reveal differentiated geoelectric behaviours. The Amazonian Craton exhibits a high-conductivity domain associated with the replacement of a delaminated lithosphere. The Parnaíba block comprises two distinct tectonic domains: the resistive Grajaú block and the conductive Teresina block. Their resistivity contrast is associated with magmatic activity, which is more intense in Teresina. However, Cretaceous extensional events related to the opening of the South Atlantic may have also influenced it. In the Borborema Province, resistive and conductive signatures at lower crustal depth are identified, providing evidence of collisional events associated with its formation in the Neoproterozoic. These deep resistivity models provide new evidence for the crustal amalgamation of the Parnaíba Basin and offer insights into the tectonic processes that shaped Western Gondwana.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"909 ","pages":"Article 230777"},"PeriodicalIF":2.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The subsurface structure of salt diapirs revealed with electrical resistivity models in the Shurab area, Central Iran","authors":"Mohammad Filbandi Kashkouli ,&nbsp;Abolghasem Kamkar-Rouhani ,&nbsp;Alireza Arab-Amiri ,&nbsp;Matthew J. Comeau ,&nbsp;Hakim Esmaeili Oghaz","doi":"10.1016/j.tecto.2025.230774","DOIUrl":"10.1016/j.tecto.2025.230774","url":null,"abstract":"<div><div>Salt diapirs are of interest due to their unique properties that make them ideal for secure, long-term subsurface storage, including for CO₂, natural gas, and radioactive waste. However, their utilization requires an understanding of their structure, which can be achieved with geophysical imaging. It is often a challenge to delineate salt diapirs with seismic reflection methods; therefore, we employ electromagnetic methods. We aim to a) highlight how magnetotellurics can identify the subsurface structure of salt diapirs, b) characterize the key tectonic structures and stratigraphic layers in the area, and c) investigate the role of faults on the distribution of diapirs. To do this we analyze an array of 253 magnetotelluric measurements and generate electrical resistivity models. The study area lies in the Shurab region, Central Iran, where numerous salt diapirs are observed near the surface. Overall, the models show a deformed southwestern zone and an undisturbed northeastern zone. Throughout the area, a thin (∼100 m) surface layer (1–100 Ωm) is underlain by a thick (up to 1000 m) low resistivity (&lt;1 Ωm) layer, interpreted to be sediments of the Upper Red Formation. Below this is a higher resistivity (3–30 Ωm) layer that is complex and variable in depth and thickness, particularly in the southwest, where it shallows. This corresponds to the Lower Red Formation, which is the main salt layer and encompasses the diapirs. The electrical resistivity models successfully determine the locations, boundaries, and depths of salt diapirs within the area. Furthermore, they reveal that the salt diapirs are laterally extended along fault zones. This result provides valuable insights into the area's tectonic evolution and structural framework. Based on these subsurface images and geological information, we conclude that the tectonic activity along the Sen-Sen, Ab-Shirin, and Dehnar faults had a primary role in the formation of the salt diapirs.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"909 ","pages":"Article 230774"},"PeriodicalIF":2.7,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-resolution mapping of North America suggests numerous low-velocity zones above and below the mantle transition zone","authors":"Steve A.B. Carr ,&nbsp;Tolulope Olugboji ,&nbsp;Jeffrey Park ,&nbsp;Shun-ichiro Karato","doi":"10.1016/j.tecto.2025.230775","DOIUrl":"10.1016/j.tecto.2025.230775","url":null,"abstract":"<div><div>We investigate seismic discontinuities across the middle of Earth's mantle beneath a large seismic array that spans the North American continent. We provide robust constraints on the depth distribution, sharpness, and spatial variation of seismic discontinuities by processing high-resolution Ps-converted seismic waves (∼0.5 Hz) through a novel denoising filter called CRISP-RF (<em><strong>C</strong>lean <strong>R</strong>eceiver function <strong>I</strong>maging with <strong>Sp</strong>arse <strong>R</strong>adon <strong>F</strong>ilters)</em>. In the upper mantle, above the mantle transition zone (MTZ), we observe a sharp velocity decrease at depths that vary from ∼290 km to ∼390 km. In the lower mantle, below the MTZ, we observe another sharp velocity decrease at depths that vary from ∼800 km to ∼1400 km<strong>.</strong> The lower-mantle discontinuities cluster at a depth of ∼940 km, while deeper converters (&gt; 1100 km) are less likely. We evaluate our results against two leading hypotheses: basalt enrichment due to incomplete mixing and dehydration melting in which MTZ water is transported into the upper or the lower mantle, but rarely simultaneously. We conclude that our results are more consistent with a scenario where the complex interplay between composition, volatile content, and subduction history, produces disconnected regions of velocity-inversion interfaces when past convective motions bring hydrated MTZ rock into the hydrophobic upper and lower mantles.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"908 ","pages":"Article 230775"},"PeriodicalIF":2.7,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pliocene-Quaternary deformational structures in the eastern Algarve continental shelf, Gulf of Cadiz","authors":"María Luján ,&nbsp;Francisco José Lobo ,&nbsp;Thomas Mestdagh ,&nbsp;Álvaro Carrión-Torrente ,&nbsp;Juan Tomás Vázquez ,&nbsp;Mª. Carmen Fernández-Puga ,&nbsp;David Van Rooij","doi":"10.1016/j.tecto.2025.230773","DOIUrl":"10.1016/j.tecto.2025.230773","url":null,"abstract":"<div><div>Evidences of tectonic deformation from the Pliocene to the Quaternary are evaluated on the northern Gulf Cadiz continental margin along the eastern Algarve continental shelf between the Guadiana River and Faro city, in a regional compressive context close to the Eurasia-Africa plate boundary. We studied an extensive set of 2D high-resolution seismic reflection profiles framed within previously published seismic-stratigraphic models. The seismic stratigraphic interpretation and regional correlation allow us to identify a major Middle Pleistocene (0.9–026 Ma) angular unconformity along the shelf, plus deformational structures affecting widespread depositional hiatuses in the Pliocene-Quaternary sedimentary units of the study area. Several deformation features indicate neotectonic activity: ENE-WSW to NE-SW thrusts moving pre-Middle Pleistocene shelf deposits and N-S to NW-SE folds and NNE-SSW to NNW-SSE high-angle normal faults affecting Middle to Upper Pleistocene shelf deposits. These structures are interpreted under the light of two major deformation phases that took place in the Algarve continental shelf. A first phase of Pre-Middle Pleistocene thrusting agrees with a dominant transpressive regime along the southwestern Iberian margin since the Tortonian, which is also recorded in the deep-water contouritic record of the southern Iberian margin, where compressional events caused intensification of the Mediterranean Outflow Water. A Middle to Upper Pleistocene tectonic phase is characterized by less intense deformation of the sedimentary cover involving individual structures (i.e., folds and faults), some of which remained active at least up to the Last Glacial Maximum. This more recent tectonic deformation is compatible with slowly uplifting trend recognized in the Portuguese mainland, and coetaneous diapiric reactivation that locally deformed Late Quaternary sediments along the southwestern Iberian margin. The study lends additional evidence of regional neotectonic activity producing Pliocene to Pleistocene deformation, and having ultimate implications for seismic hazard assessment, in offshore settings close to coastal population centers along the southern Portuguese coast.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"908 ","pages":"Article 230773"},"PeriodicalIF":2.7,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of micas on the strength of experimental granitoid fault gouge","authors":"W. Zhan ,&nbsp;A.R. Niemeijer ,&nbsp;A. Berger ,&nbsp;C.J. Spiers ,&nbsp;F.E. Gfeller ,&nbsp;M. Herwegh","doi":"10.1016/j.tecto.2025.230772","DOIUrl":"10.1016/j.tecto.2025.230772","url":null,"abstract":"<div><div>Sheet silicates play an important role in shaping crustal rheology and shear localization at shallow depths through their low strength. However, their effect at deeper levels (&gt;3 km) remains unclear. We conducted hydrothermal ring shear experiments on three simulated gouges with similar quartz content but varying mica types and contents. Applied temperatures <span><math><mi>T</mi></math></span> ranged from 20 to 650 °C, with sliding velocities <span><math><mi>V</mi></math></span> between 0.03 and 1 μm/s, and an effective normal stress and pore water pressure of 100 MPa. Shear strains up to 30 were attained.</div><div>At 1 μm/s and 20 °C, granitoids exhibit a higher friction coefficient (μ = 0.81) than the muscovite-rich (μ = 0.47) and biotite-rich gouges (μ = 0.44). With increasing <span><math><mi>T</mi></math></span> at a fixed <span><math><mi>V</mi></math></span> of 1 μm/s, μ of granitoids decreases to 0.61 at 650 °C, whereas muscovite- and biotite-rich gouges strengthen (μ = 0.56–0.69) until <em>T</em> reaches 200–450 °C. At 650 °C, weakening is observed in granitoid and muscovite-rich gouges as <span><math><mi>V</mi></math></span> decreases, while biotite-rich gouge shows no change. Granitoids are weaker than the mica-rich gouges once <span><math><mi>V</mi></math></span> decreases to 0.03 μm/s and <span><math><mi>T</mi></math></span> reaches 650 °C. All gouges at 650 °C exhibit μm-wide principal slip zones, featuring microstructures consistent with dissolution-precipitation creep (DPC). These include truncated grain contacts, mineral precipitates, submicrometer grain size and low porosity. Muscovite breakdown and biotite formation occurs in muscovite-rich gouge as they weaken. Our results imply that mica enrichment in granitoid faults can lead to a weaker upper crust and stronger middle crusts as they weaken less than granitoids. The onset of DPC may trigger a frictional-viscous transition at greenschist facies depths.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"908 ","pages":"Article 230772"},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}