Tectonophysics最新文献

{"title":"Active shortening and aseismic slip along the Cephalonia Plate Boundary (Paliki Peninsula, Greece): Evidence from InSAR and GNSS data","authors":"Varvara Tsironi ,&nbsp;Athanassios Ganas ,&nbsp;Sotirios Valkaniotis ,&nbsp;Vasiliki Kouskouna ,&nbsp;Efthimios Sokos ,&nbsp;Ioannis Koukouvelas","doi":"10.1016/j.tecto.2024.230400","DOIUrl":"https://doi.org/10.1016/j.tecto.2024.230400","url":null,"abstract":"<div><p>We present a comprehensive analysis of geodetic data, including InSAR and GNSS, to assess the interseismic deformation of the Paliki peninsula in western Cephalonia, Greece. The region is prone to frequent earthquakes, due to its proximity to the Cephalonia Transform Fault (CTF), a 140 km long dextral strike-slip fault (striking NNE-SSW) that accommodates the relative motion between the Apulian and Aegean lithospheric plates. Our analysis covers the period from 2016 to 2022 and leverages LiCSBAS, an open-source package, for InSAR time series analysis with the N-SBAS method. The results of the InSAR analysis demonstrate deformation rates between 2 and 5 mm/yr in the line-of-sight (LOS) direction of the satellite. We constructed <em>E</em>-W velocity profiles that provided a velocity gradient terminating against the outcropping trace of the seismic fault of the 3 February 2014 earthquake (M6.1) near Atheras. This geodetic evidence indicates a ∼ 1 mm/yr minimum aseismic slip (fault creep) motion along the February 2014 seismic fault, during 2016–2022. Positive LOS values in both satellite imaging geometries show that the coastal town of Lixouri experiences uplift of 1 mm/yr. East-West velocity cross-sections across western Cephalonia including Gulf of Argostoli reveal several velocity discontinuities, possibly bounded by active faults and/or landslides. The <em>E</em>-W shortening rate between Lixouri and Argostoli areas amounts to 1.5 mm/yr corresponding to −187 ns/yr (nanostrain/yr) of tectonic strain. Our results suggest a complex deformation pattern on the Paliki peninsula with strain accumulation along strike-slip and reverse-slip faults. We also inverted GNSS velocities from Italy and Greece, across the Cephalonia segment of CTF (assuming elastic half-space) and obtained a locking depth of 13 km, and a slip rate of 17.3 ± 0.8 mm/yr.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230400"},"PeriodicalIF":2.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541146","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":"Geotectonic architecture beneath Northern Vietnam revealed by local earthquake tomography combining seismic data from multiple networks","authors":"Vinh Long Ha ,&nbsp;Hsin-Hua Huang ,&nbsp;Bor-Shouh Huang ,&nbsp;Le Minh Nguyen ,&nbsp;Van Duong Nguyen ,&nbsp;Thi Giang Ha ,&nbsp;Quang Khoi Le ,&nbsp;Quoc Van Dinh ,&nbsp;Tu Son Le ,&nbsp;Tien Hung Nguyen ,&nbsp;Cong Nghia Nguyen ,&nbsp;Kyle Ken Smith ,&nbsp;Thuy Thanh Pham","doi":"10.1016/j.tecto.2024.230402","DOIUrl":"https://doi.org/10.1016/j.tecto.2024.230402","url":null,"abstract":"<div><p>Extrusion tectonics driven by the collision of Indian-Eurasian continents and the relative motion among microcontinents (e.g. South China, Simao-Indochina blocks) has led to multi-phase and complex geological activity and structures in Northern Vietnam. While extensively studied, its detailed crustal architecture in association with multiple large-scale shear zones and plate boundaries remains unclear and is key to resolving long-lasting tectonic debates. This study constructs the first 3-D regional S-wave velocity (Vs) model with consistent P-wave velocity (Vp) and Vp/Vs ratio models by jointly using the crustal and head waves (e.g. Pg/Sg and Pn/Sn phases) from an augmented earthquake catalog combining the Vietnam National Earthquake Catalog (VNCAT) and the data from multiple adjacent seismic networks. The quality of phase picking and earthquake location incorporating seismic data from various sources are carefully examined and collected for the tomographic inversion. We use a stepwise joint inversion scheme to subsequently constrain the earthquake location, 1-D and 3-D velocity models. The output models suggest that the Song Ma suture represents a better candidate for the Indochina-South China boundary rather than the Red River Shear Zone. The latter seems to act as a crustal structure while the former and the Dien Bien Phu Fault are likely lithospheric ones. Several other geologic features such as the Tu Le volcanic basin, the Song Hong basin, and the Day Nui Con Voi metamorphic complex are also clearly depicted and discussed in the model. This new set of the Vp, Vs, and Vp/Vs models could further contribute to better assessment to seismic hazards in the northern Vietnam.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230402"},"PeriodicalIF":2.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541147","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":"Strong controlling effect of stress evolution on the 2022 Ms5.0 Honghe earthquake sequence","authors":"Ye Zhu ,&nbsp;Wenjie Fan ,&nbsp;Yingfeng Ji ,&nbsp;Weiling Zhu ,&nbsp;Lili Feng ,&nbsp;Rui Qu","doi":"10.1016/j.tecto.2024.230401","DOIUrl":"10.1016/j.tecto.2024.230401","url":null,"abstract":"<div><p>Understanding stress evolution patterns as a response to earthquake ruptures at geologically complex tectonic faults is vital because of the role of fault geometry as a source for the stress evolutionary constraints. Here, we analyze the 2022 Ms5.0 Honghe earthquake sequence and calculate the tectonic stress distribution of the two Ms. ≥ 3.5 earthquakes in this sequence. Results indicate that the focal mechanism type of the sequence obtained corresponds to strike-slip motion with an ESE-oriented strike and a steeply dipping NE-oriented nodal plane. The focal region is subjected to NNW-oriented horizontal compression and ENE-oriented horizontal tension. We find that the adjacent Ailaoshan fault constituted the major seismogenic fault of the mainshock and the regional stress field exerted a strong controlling effect on the associated postseismic events. Our results suggest that the stabilization of tectonic faults may help to enhance the effects of stress accumulation on the occurrence of medium-to-strong earthquakes.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230401"},"PeriodicalIF":2.7,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141463900","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":"A revolution in understanding SE Asia geodynamics since 20.5–18 Ma","authors":"Jean-Claude Sibuet ,&nbsp;Siqing Liu ,&nbsp;Minghui Zhao ,&nbsp;Wen-Nan Wu ,&nbsp;Yih-Min Wu ,&nbsp;Jinhui Cheng ,&nbsp;Jonny Wu","doi":"10.1016/j.tecto.2024.230397","DOIUrl":"https://doi.org/10.1016/j.tecto.2024.230397","url":null,"abstract":"<div><p>We present an updated evaluation of SE Asian geodynamics that includes the interactions of the South China Sea (SCS) marginal basin with surrounding plates since the end of SCS spreading 20.5–18 Ma. Newly available Ar³⁹/Ar⁴⁰ ages of SCS oceanic crust drilled at IODP U1431 near the SCS East basin extinct spreading center are older than 18 Ma. Conversely, the oldest ages of the Luzon arc and forearc at Taiwan's Lanyu island, Coastal range and Lichi mélange are 17–18 Ma, suggesting that onset of the Manila subduction zone may have begun a few m.y. earlier. Before ∼20.5 Ma, the northern part of the Manila transcurrent fault (MTF), considered as the western boundary of the Ryukyu subduction zone, was a left-lateral lithospheric-scale shear zone. From ∼20.5–18 Ma to ∼7 Ma, this portion of MTF was connected to the Manila trench. Since ∼7 Ma, the MTF extended into the Taiwan Longitudinal valley and continued southwards to north Luzon island as near-vertical, left-lateral shear zone. Today, south of ∼24°N, the MTF protrudes down to 30 km depths and terminates above the deeper Manila slab. Since ∼7 Ma, the whole MTF shifted 400 km westward with respect to Eurasia and rotated ∼23° clockwise to become oriented ∼NS north of 16°N latitude. We identify a tear fault in the Eurasian (EU) plate north of the Ryukyu trench that is located south of the Myako and Yonaguni islands. Since ∼10 Ma, the tear continuously progressed westward within EU crust, with the Philippine Sea plate progressively subducting northwestward between the two lips of the tear fault. A RFF (ridge-fault-fault) triple junction was active in the EU crust before 20.5 Ma, from 10 to 7 Ma, and since 2 Ma. This triple junction was always located on the MTF with one branch of the MTF on each side of the triple junction, and the third branch being the spreading center.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230397"},"PeriodicalIF":2.7,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541145","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":"Numerical simulation of stress evolution and seismic moment budget along the central segments of the Xianshuihe-Xiaojiang fault system: Implications for seismic hazard assessment","authors":"Luyuan Huang ,&nbsp;Shi Chen","doi":"10.1016/j.tecto.2024.230394","DOIUrl":"10.1016/j.tecto.2024.230394","url":null,"abstract":"<div><p>The central segments of the Xianshuihe-Xiaojiang fault system (CSXXFS), which intersect densely populated areas, have remained seismically quiet without any strong earthquakes of M ≥ 7 for nearly two centuries. As such, conducting a comprehensive seismic hazard assessment of the CSXXFS serves as a crucial component of disaster mitigation efforts. To achieve this, we developed a finite element model that integrates heterogeneous mechanical properties constrained by interseismic deformation to estimate the fault locking depths within the CSXXFS. Subsequently, we performed an analysis of the seismic moment budget and Coulomb stress change to comprehensively assess the seismic hazards in the vicinity of the CSXXFS. Our findings revealed an overall average locking depth of 10 km for the Xianshuihe-Xiaojiang fault system (XXFS) and 15 km for the Daliangshan fault (DLSF). The discrepancy between the seismogenic depth and the fault locking depth indicates the presence of deep creep in certain segments of the CSXXFS. Additionally, historical earthquakes have caused stress modulation, resulting in potential earthquakes being either delayed or advanced in different segments of the CSXXFS. Specifically, the future seismic hazard is delayed in the entire Zemuhe fault (ZMHF), the northern segment of the Anninghe fault (ANHF), the southern section of the Shimian-Yuexi segment of the north Daliangshan fault (NDLSF), and the southernmost part of the south Daliangshan fault (SDLSF). Conversely, the potential earthquake on the Mianning-Xichang segment of the ANHF and the majority of the DLSF have been advanced due to positive earthquake-induced stress. Our estimation of the seismic budget suggests that the ANHF, ZMHF, NDLSF, and SDLSF have the potential to host earthquakes with magnitudes of M 6.9, M 7.3, M 7.4, and M 7.1, respectively. By adopting this integrated seismic hazard analysis, we highlight the necessity of closely evaluating potential risks and implementing appropriate mitigation strategies in this area.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230394"},"PeriodicalIF":2.7,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141463766","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 and Potential Field Constraints on Upper Crustal Architecture of Inner Bering Shelf, Offshore Southwestern Alaska","authors":"Rajesh Vayavur ,&nbsp;Andrew J. Calvert","doi":"10.1016/j.tecto.2024.230398","DOIUrl":"10.1016/j.tecto.2024.230398","url":null,"abstract":"<div><p>Southwestern Alaska encompasses a group of fault-bounded tectonostratigraphic terranes that were accreted to North America during the Mesozoic and Paleogene. To characterize the offshore extension of these terranes and several significant faults identified onshore, we reprocessed three intersecting multichannel deep seismic reflection profiles totaling ∼750 line-km that were shot by the R/V Ewing across part of the inner Bering continental shelf in 1994. Since the uppermost seismic section is often contaminated by high amplitude water layer multiples from the hard and shallow seafloor, the migrated reflection images are supplemented with high-resolution P wave velocity models derived by traveltime tomography of the recorded first-arrivals to depths of up to 2000 m. Additionally, other geophysical datasets such as seismicity, well logs, high resolution satellite-altimetry gravity, air-borne magnetics, ship-board gravity and magnetics, are also incorporated into an integrated regional interpretation. We delineate the offshore extension of the major mapped geological elements, including the Togiak fault (TGF), East Kulukak fault (EKF), Chilchitna fault (CF), Lake Clark fault (LCF), Togiak terrane (TT), Goodnews terrane (GT), Peninsular terrane (PT), Northern Kahiltna flysch (NKF) and Southern Kahiltna flysch (SKF) deposits, and the regional suture zone. The geophysical evidence from this study suggest that the major faults and terrane boundaries of southwestern Alaska, excluding the LCF, not only extend beneath the Bering shelf offshore but also appear to rotate, forming a trend parallel to the inactive Beringian margin. The LCF extends offshore but likely terminates in the northeastern part of the Bristol Bay basin. Additionally, the constraints from seismicity data indicates that while the major faults in southwestern Alaska exihibit some activity onshore, they remain dormant in the offshore region. These new findings will contribute to a better understanding of terrane accretion processes and existing fault models of southwestern Alaska.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230398"},"PeriodicalIF":2.7,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141463865","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 Calipatria Deformation Zone revealed from 2D seismic profiles in the Mexicali Valley. Evidence of an ancient plate boundary?","authors":"Carlos Simón Reyes-Martínez ,&nbsp;Mario González-Escobar ,&nbsp;Juan Carlos Montalvo-Arrieta ,&nbsp;Uwe Jenchen ,&nbsp;Fernando Velasco-Tapia","doi":"10.1016/j.tecto.2024.230396","DOIUrl":"10.1016/j.tecto.2024.230396","url":null,"abstract":"<div><p>The geological structures buried in the Mexicali Valley need to be better constrained. The Calipatria Fault is an essential key as it could represent an old strand of the San Andreas Fault system. Previous and two new seismic profiles in the Mexicali Valley and Altar Desert have been processed and interpreted. Chaotic and Low Amplitude Seismic Anomalies (CLASA) observed in the seismic profiles have revealed the Calipatria Deformation Zone, showing a high correlation with gravity maxima. This correlation could extend to the Salton Sea, resulting in an ancient plate boundary connected to the Southern San Andreas Fault. We propose that this deformation zone is a transtension region due to the change from an orthogonal rifting to an oblique rifting similar to the observations on analog models based on the northern Gulf of California. This change in the rifting style produced narrow basins that facilitated continental breakup observed on magnetic anomalies and deep wells penetrating igneous rocks.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230396"},"PeriodicalIF":2.7,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141409463","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":"Lithological control of the active Mejillones fault from Triassic to Quaternary, northern Chile","authors":"Kellen Azúa ,&nbsp;Francisco Pastén-Araya ,&nbsp;José González-Alfaro ,&nbsp;José Salomón ,&nbsp;Sergio Ruiz ,&nbsp;César Pastén ,&nbsp;Pablo Salazar","doi":"10.1016/j.tecto.2024.230395","DOIUrl":"10.1016/j.tecto.2024.230395","url":null,"abstract":"<div><p>Understanding the lithological control of crustal faults near cities is important for assessing the seismic hazard and characterising complex fault systems. We studied the Mejillones Fault (MF), located near one of the strategic ports in northern Chile. The MF is an active geological fault that extends 40 km in the N-S direction and is part of an extensive complex system of structures known as the Atacama Fault System (AFS). We built an S-wave tomography model using seismic ambient noise data that was recorded continuously in a dense network of stations from 2013 to 2015. The tomographic maps exhibited velocity anomalies that correlate with surface geology. We found lower velocities in the western part of the MF than in the eastern zone, with a shear wave velocity (Vs) of about 2.4 km/s, associated to fractured metamorphic rocks (Triassic) and marine sediments (Neogene-Quaternary). Higher velocities (Vs &gt; 3.0 km/s) in the eastern part of the fault are related to igneous rocks from the Upper Jurassic. The difference in velocities between the western and eastern zones of the MF remained persistent in depth. The potential depth of the MF could be &gt;5 km and delimits the boundary between 2 different geological zones. Intermediate Vs (∼2.8 km/s) at −23.25°, observed up to 4 km depth, can be associated with andesitic rocks deposited in an intra-arc basin (Upper Triassic) and accommodated by the MF over the last ∼200 Myr, evidencing the activity of this fault from Triassic to Quaternary.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230395"},"PeriodicalIF":2.7,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141401693","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":"Unraveling Precambrian cratonic roots beneath South America: A contribution from surface wave tomography","authors":"André V.S. Nascimento ,&nbsp;George S. França ,&nbsp;Carlos A.M. Chaves ,&nbsp;Giuliano S. Marotta ,&nbsp;Marcelo Assumpção","doi":"10.1016/j.tecto.2024.230392","DOIUrl":"10.1016/j.tecto.2024.230392","url":null,"abstract":"<div><p>We examine some aspects of the tectonic evolution of Precambrian cratonic roots beneath South America based on lithospheric distribution of shear-wave velocities. We derive our model by inverting 26,984 fundamental mode Rayleigh wave group velocity dispersion curves, at periods of 9–180 s. We first regionalize our measurements and then invert the result for a 3D S-wave velocity model extending to 200 km depth. Fast velocities beneath the Amazonian and São Francisco cratons, and beneath buried cratonic units in the Parnaíba and Paraná basins, are long wavelength features consistent with previous tomography studies. For the Amazonian craton at 150 km depth, we find an increase of velocities with province age, except for the Maroni-Itacaiúnas province, where we hypothesize that K'Mudku intraplate tectono-thermal events at the middle-late Mesoproterozoic and emplacement of a large igneous province following the breakup of Pangea could have altered at least partially its lithosphere. Our results are consistent with a São Francisco paleocontinent whose borders extend beyond the surface limits of the present São Francisco craton into the neighboring Araçuaí and Brasília belts. Based on slow shear-wave velocities in the upper mantle beneath the Borborema province, consistent with lithospheric thinning, we argue that a possible cratonic root of the São Francisco Paleocontinent beneath this province has likely been eroded away. This analysis is further corroborated by tectonic events that led to the alteration of the Borborema mantle, including hydration in the Paleoproterozoic, rifting in the early-middle Tonian, reworking during Neoproterozoic Brasiliano events, and lithospheric stretching during the breakup of Pangea. Finally, we also image a fast shear-wave velocity structure in the region of the Río de la Plata craton, consistent with magnetotelluric studies.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"883 ","pages":"Article 230392"},"PeriodicalIF":2.7,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141401444","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":"Late Pleistocene Fault Slip Rate within the Bole Basin: Insights into deformation kinematics in the Central Tian Shan","authors":"Zongkai Hu,&nbsp;Xiaoping Yang,&nbsp;An Li,&nbsp;Haibo Yang","doi":"10.1016/j.tecto.2024.230391","DOIUrl":"10.1016/j.tecto.2024.230391","url":null,"abstract":"<div><p>Tian Shan is a vast and highly seismically active intracontinental mountain range. GPS measurements and field studies have shown that E-W and NW-SE trending thrusts and fault-related folds are distributed across central Tian Shan. However, few studies have determined the fault and fault-related-fold activity in the Bole Basin, the northernmost part of central Tian Shan. In this study, we focus on the Alashak Fold, which is situated along the southern margin of the Bole Basin. Using high-resolution uncrewed aerial vehicle-Digital Elevation Model data, field observations, and detailed mapping, we determined that the Alashak Fold is characterized by a trishear fault-propagation fold. Along the Alashak River, we identified five levels of fluvial surfaces, the T3 terrace was continuously preserved across the fold. Radiocarbon and surficial ¹⁰Be dating were used to determine the exposure age of the deformed T3 terrace. The folding characteristics of T3, trishear inversed modeling, and abandonment age indicate that the Alashak Fault has an uplift rate of 0.8 ± 0.3 mm/yr, a dip-slip rate of 4.2 ± 1.2 mm/yr, and a crustal shortening rate of 4.0 ± 1.2 mm/yr since the late Pleistocene, respectively. The Alashak and Latgan Faults intersect at a depth of 1.2 km, enclosing a wedge-shaped block. Our study emphasizes that tectonic activity along the southern margin of the Bole Basin has played a significant role in north-south shortening within central Tian Shan, as measured by geological measurements since the late Pleistocene. The Alashak Fault can potentially generate moderate–strong (Mw 5.0–7.0) earthquakes, while the Alashak and Latgan Faults can generate major (Mw 7.2) earthquakes.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"883 ","pages":"Article 230391"},"PeriodicalIF":2.9,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141402023","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}