Tectonophysics最新文献

{"title":"Paleoearthquake sequence in the eastern segment of the Serteng Shan frontal fault (Hetao graben, North China) during the last 50 ka","authors":"Xin Sun ,&nbsp;Yanxiu Shao ,&nbsp;Wenjun Zheng ,&nbsp;Dongli Zhang ,&nbsp;Haiyun Bi ,&nbsp;Jinhua Du","doi":"10.1016/j.tecto.2025.230894","DOIUrl":"10.1016/j.tecto.2025.230894","url":null,"abstract":"<div><div>To better constrain the paleoseismicity and assess the seismic hazard, we investigated the eastern segment of the Serteng Shan frontal fault along the northern margin of the Ordos Block. The Ordos Block in northern China has a stable interior but is surrounded by seismically active faults. Several historical earthquakes with magnitude ≥<em>M</em>7 have ruptured along the northern boundary of the Ordos Block. Using excavated trenches, the eastern segment of the Serteng Shan frontal fault along the northern margin of the Ordos Block was investigated. Seven events were identified based on distinct geological markers, such as colluvial wedges. To constrain the timing of these events, 28 samples were collected and dated using the optically stimulated luminescence (OSL) method. The dating indicates show that all seven events occurred after ∼90 ka, with the five most recent events occurring after 50 ka. Based on OxCal modeling results, the most recent event is inferred to have occurred at 7.0 ± 1.1 ka. The penultimate and preceding events occurred at approximately 25.0 ± 2.2 ka, 35.6 ± 1.5 ka, 41.3 ± 1.9 ka, and 46.2 ± 2.4 ka, respectively. The minimum recurrence intervals are approximately 5 ka, or multiples thereof, resulting in longer intervals of up to ∼20 ka. Combining the displacement of the T6 terrace and their corresponding ages, a uniform vertical slip rate of 0.15 ± 0.02 mm/yr over the last 90 ka is estimated. The slip rates and recurrence intervals indicate that the eastern segment of the Serteng Shan fault experiences a low rate of surface-rupturing earthquakes. This behavior could be explained by the effect of unloading of a mega-paleolake in the Hetao Basin at ∼50 ka. These results provide new constraints on long-term slip behavior and inform seismic hazard assessment.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230894"},"PeriodicalIF":2.6,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893151","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":"3D gravity modelling of the basement of the Mitidja Basin (Algeria): Approach and tectonic implications","authors":"Rafik Yalaoui ,&nbsp;Reda Ouyed ,&nbsp;Mouloud Idres ,&nbsp;Saddek Samai ,&nbsp;Merzouk Ouyed","doi":"10.1016/j.tecto.2025.230892","DOIUrl":"10.1016/j.tecto.2025.230892","url":null,"abstract":"<div><div>The modelling of the morphology and depth of the basement of sedimentary basins is essential for various geological and geophysical investigations, including tectonic analysis, hydrogeological studies, and seismic hazard assessment. In this study, a three-step approach was applied to model the crystalline basement of the Mitidja Basin (Algeria) in the absence of borehole or seismic data.</div><div>This approach combines energy spectrum analysis to identify characteristic gravity frequencies, optimisation of gravity anomalies from outcrop zones, and 3D inversion based on the Parker-Oldenburg algorithm. It enabled the mapping of the crystalline basement of the Mitidja Basin for the first time, revealing a complex structure influenced by two transverse faults associated with regional tectonics. These dextral and sinistral faults play a key role in the deformation and segmentation of the reverse fault systems that bound the Mitidja Basin to the north and south, a dynamic corroborated by focal mechanisms of recent earthquakes.</div><div>The resulting map highlights two distinct parts of the basin, separated by basement uplift in the centre. The observed correlation between the crystalline and Plaisancian basements suggests significant hydraulic potential in areas not covered by geo-electrical surveys, where borehole data could provide confirmation.</div><div>This study also emphasises the importance of further seismo-tectonic research in this region, particularly around Algiers, to improve seismic hazard assessment and water resource management.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230892"},"PeriodicalIF":2.6,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896378","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":"An Upper Devonian foredeep basin in the Southern Central Iberian Zone (Variscan Iberian Massif): Consequences for Variscan plate dynamics","authors":"Francisco J. Rubio Pascual ,&nbsp;Luis M. Martín Parra ,&nbsp;Jerónimo Matas ,&nbsp;L. Roberto Rodríguez Fernández ,&nbsp;Luis González Menéndez ,&nbsp;Diana Moreno-Martín ,&nbsp;Rubén Díez Fernández","doi":"10.1016/j.tecto.2025.230893","DOIUrl":"10.1016/j.tecto.2025.230893","url":null,"abstract":"<div><div>New field research and revision of previous works in the Variscan Iberian Massif unravel the existence of an Upper Devonian foredeep basin in the southern Central Iberian Zone, close to the suture area with the Ossa-Morena Zone. Superimposed Tournaisian-Visean extensional basins, a Serpukhovian-Bashkirian foreland basin, and the Late Variscan wrench tectonics obscure this foredeep basin. This synorogenic sedimentation is related to the Late Devonian continental subduction featured by a high-pressure metamorphic belt exposed to the south of this area. The unravelling of this trough with marine turbiditic sedimentation and fragments of terrestrial plant fossils, allows the reinterpretation of the Upper Devonian deposits along the northern half of the Iberian Massif. It also explains the lack of Middle Devonian sedimentary rocks in most of the massif. The geometry and stratigraphy correspond to a collisional foreland basin with its classical depozonal elements. The structure of the foreland basin solves discussions about tectonic polarity in the Ossa-Morena - Central Iberian Variscan collision, the upper plate thus corresponds to the Upper Allochthon of the Ossa-Morena Zone. The tracking of the NE migration (current coordinates) of the bulge area suggests a ∼ 5.5 cm/yr rate of Upper Devonian convergence and up to ∼800 km of continental underplating. We also propose a correlation with the Upper Devonian high-pressure Basal Units and the synorogenic sediments of the NW Iberian Massif. Conclusions can be extended to the plate architecture between other peri-Gondwana terranes of the Armorican assemblage and the northern Gondwana margin.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230893"},"PeriodicalIF":2.6,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893150","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":"Present-day inter-seismic velocities and fault slip rate of Ketahun segment, Sumatran Fault System (SFS) inferred from Global Positioning System (GPS) observations","authors":"Ashar Muda Lubis ,&nbsp;Rida Samdara ,&nbsp;Rio Sahputra ,&nbsp;Lina Handayani ,&nbsp;Qiu Qiang ,&nbsp;Agnis Triahadini ,&nbsp;Muhammad Maruf Mukti ,&nbsp;Oktadi Prayoga","doi":"10.1016/j.tecto.2025.230879","DOIUrl":"10.1016/j.tecto.2025.230879","url":null,"abstract":"<div><div>The Ketahun segment of the Sumatran Fault System (SFS) is distinctive and tectonically active segment, yet the slip rate of the segment is not widely known. The Ketahun segment underwent two major earthquakes of M_s 7.6 in 1946 and M_s 6.8 in 1952, respectively. Using Global Positioning System (GPS) data, we aim to better estimate the slip rates using a dislocation elastic model following a Bayesian approach with Metropolis Markov chain Monte Carlo (MCMC) samplers to estimate optimum fault parameters. Then we determined the potential amount of cumulative energy stored at the segment. We processed raw GPS data from 35 GPS stations, combining from GIA, SuGAr, and UNIB networks during 2018–2024 using GAMIT/GLOBK software. The daily GPS solutions were constrained into the ITRF-2014 frame, and the GPS velocities were translated into Sunda block. Before we model the trench parallel GPS velocities, we attempted to correct the viscoelastic velocities due to the 2007 Mw 8.4 Bengkulu earthquake incorporating the effect of megathrust coupling on the trench parallel GPS velocities. We find the importance of viscoelastic response and megathrust coupling effect in our analysis, providing better slip rate and locking depth estimation. Our result inferred that the estimated fault slip rate is 14.5 [−1.2, +1.3] mm/yr with a locking depth of 14.4 [−4.9, +4.8] km across in the Ketahun segment. The segment is capable of generating a magnitude ∼6 to 7+ if a single earthquake occurs every 50 to 200 years.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"914 ","pages":"Article 230879"},"PeriodicalIF":2.6,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144898393","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":"Seismotectonics of the Gulf of Patras, Central Greece: New insights from earthquake relocation, focal mechanisms and stress inversion","authors":"Ioanna Nikolopoulou ,&nbsp;Efthimios Sokos ,&nbsp;Zafeiria Roumelioti ,&nbsp;Vasiliki Mouslopoulou","doi":"10.1016/j.tecto.2025.230889","DOIUrl":"10.1016/j.tecto.2025.230889","url":null,"abstract":"<div><div>The Gulf of Patras lies at the western-end of the Corinth Rift (Greece), where the crust accommodates the kinematic transition from extension, along the rift, to oblique compression, along the western end of the Hellenic Subduction System (HSS). Nevertheless, the mechanism by which this transition occurs over earthquake timescales, is unclear. In this study, we analyze eleven years of seismicity within the Gulf of Patras by performing double-difference relocation and stress inversion. The distribution of epicenters shows spatially distinct seismicity patterns with earthquakes being dense and shallow (&lt;20 km) in the northeastern gulf, diffuse and distributed over a broad range of depths (25–40 km) in the center, and sparse in the western gulf. Shallow microseismicity terminates abruptly at the junction between the gulfs of Corinth and Patras. Focal mechanism solutions suggest that shallow events are associated with E-W trending normal faulting, while deeper seismicity is linked to strike-slip faulting. The Achaia-Elia Fault System (AEFS), that traverses Peloponnese in a NE-SW direction and intersects the rift at high angles, is clearly delineated by the relocated epicenters, to step northeastward toward the city of Patras through a series of ‘en echelon’ earthquake clusters. Well-formed clusters of relocated earthquakes delineate three parallel NW-SE trending faults that extend across the Gulf of Patras, possibly linking active faults on either side of the gulf, a finding that may have implications for the seismic hazard of the city of Patras. Stress tensor analysis derived from moment tensors and focal mechanisms, indicates simultaneous strike-slip and normal faulting operating at different depths within the Gulf of Patras.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230889"},"PeriodicalIF":2.6,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896379","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":"Refined crustal thermal structure constrained by thermal infrared remote sensing reveals ancient continental relicts in the south China block","authors":"Wenna Zhou ,&nbsp;Bohu Xu ,&nbsp;Hai Tang ,&nbsp;Yongkang Chan ,&nbsp;Dailei Zhang ,&nbsp;Yunmeng Wu ,&nbsp;Qiang Li","doi":"10.1016/j.tecto.2025.230882","DOIUrl":"10.1016/j.tecto.2025.230882","url":null,"abstract":"<div><div>The South China Block, recognized as a pivotal geological domain for investigating continental tectonic evolution, hosts abundant geothermal and mineral resources. Accurate characterization of its crustal thermal structure is critical for deciphering geothermal anomalies and advancing understanding of regional tectonic dynamics. This study establishes an innovative inversion framework constrained by satellite thermal infrared remote sensing data to enhance spatial resolution and precision in thermal structure analysis. Through application of the split-window algorithm to Moderate Resolution Imaging Spectroradiometer (MODIS)-derived surface temperature datasets, we develop a surface heat flow inversion model that integrates the Curie depth and surface thermal parameters. Integration of remote sensing-derived ground temperature results with inverted surface heat flow data facilitates a more nuanced understanding of the thermal structure within the South China Block. Results indicate more consistency between the upper crustal thermal structure resolved by our method and empirical geothermal well measurements, confirming the validity of our approach. Notably, the deep crust thermal structure exhibits marked lateral and vertical heterogeneity, with low-temperature zones delineating several ancient continental relicts. These relicts manifest as distinct low-temperature anomalies corresponding to crustal thickening zones and lithospheric tectonic stabilization. Meanwhile, we suggest the possible existence of ancient continental relicts in the Jiangnan orogenic belt. This finding resolves previous limitations in interpreting ancient continental relicts that were attributed to insufficient thermal structure resolution, thereby providing novel crustal thermal structure evidence supporting an external position for the South China Block in the Rodinia supercontinent.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230882"},"PeriodicalIF":2.6,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144879265","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":"Density perturbations in the crust indicate potential for blind magmatism beneath magma-poor rifts","authors":"Emmanuel A. Njinju ,&nbsp;Folarin Kolawole ,&nbsp;Estella A. Atekwana ,&nbsp;Rasheed Ajala ,&nbsp;Eliot A. Atekwana ,&nbsp;D. Sarah Stamps ,&nbsp;Rob.L. Evans ,&nbsp;Andrew Katumwehe ,&nbsp;Peter H. Barry ,&nbsp;Suzan van der Lee ,&nbsp;John Mary Kiberu ,&nbsp;Fred Tugume ,&nbsp;Albert Kabanda ,&nbsp;Michael Taylor ,&nbsp;Joan Nakajigo ,&nbsp;Abbey Oluwasegun Isaac","doi":"10.1016/j.tecto.2025.230881","DOIUrl":"10.1016/j.tecto.2025.230881","url":null,"abstract":"<div><div>Lithospheric weakening mechanisms in non-volcanic segments of active continental rifts remain poorly understood, raising important questions about the geodynamic processes that drive magma-poor rifting. Here, we investigate the crustal and uppermost mantle structure beneath the non-volcanic Albertine-Rhino Graben (ARG) and the adjoining volcanic Edward-George Rift (EGR), East Africa. The ARG exhibits anomalous focusing of intra-rift faulting typically associated with magma-rich, early-stage rifts. Through field observations of rift structures, combined with 3D inversions and 2D forward modeling of gravity data, we investigate the potential controls on intra-rift tectonic strain in a setting with little to no magmatism. Field ground-truthing in the southern ARG reveals prominent rift-axial basement-rooted faulting that post-dates the establishment of border faults. Gravity inversion results show low-density anomalies extending from the surface to about 50 km depth beneath both the EGR and southern ARG, with the strongest anomalies under the ARG at around 15 km. 2D gravity modeling suggests that the lower crust and uppermost mantle are both thinned and less dense beneath these rift segments. In the EGR, crustal thinning and low-density anomalies align with low P-wave velocity zones, suggesting the presence of melt. Given the similar degree of crustal thinning and de-densification in the southern ARG, we infer that trapped lower-crustal melts may also exist beneath the rift, potentially contributing to the early focusing of intra-rift strain. We propose that in non-volcanic rifts, deep, unexposed (‘blind’) melts may play a key role in mechanical weakening of the lithosphere, enabling continued tectonic extension even in the absence of significant surface volcanism.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230881"},"PeriodicalIF":2.6,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886563","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":"Three-dimensional resistivity structure and its relationship to the rupture of the 1997 Kagoshima earthquake doublet (Mw 6.1 and 6.0), Japan","authors":"Keita Matsunaga ,&nbsp;Koki Aizawa ,&nbsp;Koichi Asamori ,&nbsp;Hiroki Ogawa ,&nbsp;Mitsuru Utsugi ,&nbsp;Ryokei Yoshimura ,&nbsp;Ken'ichi Yamazaki ,&nbsp;Kazunari Uchida ,&nbsp;Takeshi Matsushima ,&nbsp;Tomohiro Inoue ,&nbsp;Kohei Yonemori ,&nbsp;Hiromichi Shigematsu","doi":"10.1016/j.tecto.2025.230880","DOIUrl":"10.1016/j.tecto.2025.230880","url":null,"abstract":"<div><div>We estimated the resistivity structure in the region of the 1997 Northwestern Kagoshima earthquake doublet (March 26, Mw6.1; May 13, Mw6.0) by dense magnetotelluric (MT) observations to investigate the influence of low-resistivity zones on the initiation and termination of large inland earthquake ruptures. In addition to MT data from previous studies, we acquired new broadband MT and telluric data at 42 sites. With a total of 86 sites in approximately 50 km × 50 km area<u>,</u> we constructed a high-resolution resistivity structure through 3-D inversion. A comparison between the slip distribution and resistivity structure showed that the rupture of the mainshock in March initiated at the western edge of a low-resistivity zone, propagated westward (with a maximum slip of 0.8 m), and was ultimately arrested by another low-resistivity zone. Based on geological structures and ³He/⁴He ratios in hot springs, we suggest that magma-derived fluids, located beneath a shallow, low-permeability smectite-rich zone and granodiorite, contributed to the initiation of the mainshock rupture. Another smectite-rich zone, along with underlying high pore pressure fluids, played a role in arresting the rupture. The rupture of the mainshock in May initiated at the edge of another low-resistivity zone and propagated in two directions (with a maximum slip of 0.4 m): one along the edge of the low-resistivity zone and the other toward the low-resistivity zone, before finally stopping within the low-resistivity zone. Our findings are consistent with those from the 2016 Kumamoto earthquake (M7.3), supporting the idea that resistivity structures can help assess the spatial potential of large inland earthquakes.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"915 ","pages":"Article 230880"},"PeriodicalIF":2.6,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144898397","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":"Crustal modelling across the West and Central African Rift System, based on gravity, magnetic and seismic data","authors":"Estelle Eric Fosso Téguia M ,&nbsp;Jörg Ebbing ,&nbsp;Eyike Albert ,&nbsp;Alain Tokam ,&nbsp;Gaelle Vanessa Nana ,&nbsp;Matthew Tankersley","doi":"10.1016/j.tecto.2025.230864","DOIUrl":"10.1016/j.tecto.2025.230864","url":null,"abstract":"<div><div>The West and Central African Rift System (WCARS) extends over several geological domains, including shear zones, volcanic regions, and sedimentary basins. It is home to key geological features such as the Cameroon Volcanic Line (CVL) and the Bangui Magnetic Anomaly (BMA). Despite numerous studies, the detailed crustal structure of WCARS has not yet been fully understood. This work presents a comprehensive 3D crustal study that integrates gravity, magnetic, and seismic data, offering insights into the region’s tectonic framework, rift dynamics, and formation of the BMA. The combined analysis of density, susceptibility, and topographic data reveals five distinct tectonic units, providing a refined understanding of the crustal composition and structure. Analysis of cross-sections along key transects over the study area demonstrates the impact of rifting and magmatic activity on crustal thinning and density distribution. The Central African Shear Zone (CASZ) and the Kandi Shear Zone (KSZ) are identified as key reactivated fault zones that have influenced the spatial distribution and evolution of rift systems. The study also highlights the role of magmatism, driven by the upwelling of molten material, in modifying crustal properties, particularly in volcanic regions such as the CVL and the Benue trough. Our findings suggest a common tectonic origin for CVL, Benue trough, and BMA, with felsic and plutonic intrusions contributing to the formation of the BMA. These results enhance our understanding of the tectonic and geodynamic evolution of the WCARS, emphasizing the role of pre-existing structures and magmatism in shaping the region’s rift architecture.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230864"},"PeriodicalIF":2.6,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144879520","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":"Updated Pn-wave anisotropic tomography and dynamics of the North China Craton","authors":"Weiwei Yin ,&nbsp;Jianshe Lei ,&nbsp;Rongyi Qian ,&nbsp;Dapeng Zhao","doi":"10.1016/j.tecto.2025.230878","DOIUrl":"10.1016/j.tecto.2025.230878","url":null,"abstract":"<div><div>We determine detailed Pn-wave anisotropic tomography of the uppermost mantle beneath the North China Craton (NCC) and its surrounding areas by inverting 84,771 manually-picked Pn-wave arrival times of 2864 local earthquakes recorded at 586 seismic stations. Our results reveal significant lateral heterogeneities in both Pn-wave velocity and anisotropy. A low-velocity (low-V) anomaly exists in the uppermost mantle north of the Ordos block, indicating that the lithosphere has been partially destroyed there, probably associated with the eastward extrusion due to the India-Asia collision and/or mantle upwelling caused by the northwestward deep subduction of the Pacific plate. Low-V anomalies appear in the central NCC, being affected by the westward deep subduction of the Pacific plate. High-velocity (high-V) anomalies with a roughly E-W fast propagation direction (FPD) exist on the eastern and western sides of the North China basin (NCB), which may be remnants of lithospheric mantle delamination due to the underplating of basaltic magma. A low-V anomaly with a nearly N-S FPD exists under the central NCB, reflecting compressional deformation there. In the middle segment of the Tanlu fault zone, a high-V anomaly exists to the west and a low-V anomaly appears to the east, whereas the pattern of velocity anomalies is opposite in the southern segment. These results suggest that the NCC destruction could be caused by combined effects of lithospheric delamination and thermal erosion.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230878"},"PeriodicalIF":2.6,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144879519","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}