Tectonophysics最新文献

{"title":"Tectonic complexity of the Incapuquio Fault System, Peruvian Andes: Paleoseismic evidence for cascading Mw7 earthquakes along the Western Andean Front","authors":"Carlos Benavente ,&nbsp;Laurence Audin ,&nbsp;Anderson Palomino ,&nbsp;Lorena Rosell ,&nbsp;Briant García ,&nbsp;Enoch Aguirre ,&nbsp;Stephane Baize ,&nbsp;Krzysztof Gaidzik ,&nbsp;Octavi Gómez-Novell ,&nbsp;Carlos Costa","doi":"10.1016/j.tecto.2025.230877","DOIUrl":"10.1016/j.tecto.2025.230877","url":null,"abstract":"<div><div>Understanding millennial-scale crustal fault activity through paleoseismological investigations is essential for seismic hazard assessment in active mountain belts. While megathrust seismicity in the Peruvian subduction zone is well-monitored, crustal fault activity along the densely populated Western Andes remains largely overlooked. In southern Peru, the Incapuquio Fault System (IFS) is a prominent active structure capable of generating recurrent Mw &gt;7 earthquakes. This study presents paleoseismic evidence from three newly excavated trenches and integrates them with three previously published sites – six trenches in total - along four fault strands of the IFS, revealing at least five surface-rupturing earthquakes during the Holocene. The overlap in time of the most recent event, the <strong>Chiribaya event (∼500 BP),</strong> identified in all trenches, suggests two possible scenarios: (1) a single large rupture propagating along the <strong>Western Toquepala Fault (WTF), Eastern Toquepala Fault (ETF), and Copapuquio Fault (CF),</strong> implying a Mw 7.5 earthquake, or (2) a cluster of closely spaced events, likely within a few centuries. Additionally, two earlier surface-rupturing earthquakes were identified: the <strong>Miculla event (∼2300 BP),</strong> recorded in the <strong>Western Toquepala Fault, Copapuquio Fault, and Sama-Calientes Fault (SCF),</strong> and the <strong>Toquepala event (∼11,600 BP)</strong>, which was identified in the <strong>Copapuquio Fault (CF).</strong> These events are <em>temporally coincident</em> with <strong>Plinian eruptions of the Misti volcano and large-scale landslides</strong> in the Andean forearc, <em>raising the possibility of interactions</em> among crustal faulting, volcanism, and stress redistribution associated with the megathrust seismic cycle. The <strong>IFS is a key seismic hazard driver in southern Peru,</strong> <em>underscoring</em> the need to expand assessments beyond megathrust activity.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230877"},"PeriodicalIF":2.6,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890023","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":"Quantitative assessment of fault reactivation risk based on pore pressure diffusion and poroelastic effects: Application to the Luzhou shale gas field, Sichuan, China","authors":"Xuhang Yang ,&nbsp;Wei Tao ,&nbsp;Renqi Lu ,&nbsp;Dahu Li ,&nbsp;Weikang Zhang","doi":"10.1016/j.tecto.2025.230876","DOIUrl":"10.1016/j.tecto.2025.230876","url":null,"abstract":"<div><div>Quantitative fault reactivation risk assessment is essential for managing induced seismicity and ensuring safe subsurface energy development. Although both pore pressure diffusion and poroelastic effects govern stress evolution during fluid injection and extraction, most existing risk assessment methods consider only pore pressure changes, thereby limiting predictive accuracy. In this study, we propose a novel Pore pressure Diffusion - Poroelastic Effects Fault Reactivation (PDPE-FR) method that couples pore pressure diffusion and poroelastic stress responses, incorporates both in-situ stress field and injection-induced stress perturbations, and accounts for parameter uncertainties related to fault orientation and stress conditions. We apply this method to the Luzhou shale gas field in China by: (1) collecting and interpolating in-situ stress measurements; (2) constructing fully coupled poroelastic finite element models to simulate injection-induced stress perturbations; and (3) integrating Coulomb stress change and normalized fault slip tendency with parameter uncertainty to evaluate fault reactivation probabilities. The results indicate high reactivation probabilities (50–80 %) for NNE-striking faults in the Fuji Syncline in Luzhou shale gas field under far-field injection, and elevated probabilities (50–90 %) for faults of all orientations under near-field conditions. Strong spatiotemporal correlations between predicted fault reactivation risks and observed seismicity, along with fracturing timelines, validate the robustness of the proposed method. In addition to assessing fault reactivation risk, the method also demonstrates broad applicability in optimizing injection-production strategies and guiding well placement.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230876"},"PeriodicalIF":2.6,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852049","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 influence of asthenospheric flow under cratonic keels on intraplate stress field and dynamic topography","authors":"Edgar Bueno dos Santos, Victor Sacek","doi":"10.1016/j.tecto.2025.230865","DOIUrl":"https://doi.org/10.1016/j.tecto.2025.230865","url":null,"abstract":"In the present work, we used thermo-mechanical numerical models with realistic rheology for the crust and mantle to assess how the asthenospheric flow under cratonic keels affected the topography and intraplate stress field. We tested different thickness values for the cratonic keel and the relative speed between the lithosphere and the base of the upper mantle. We observed that the horizontal flow of the asthenosphere under the cratonic keel induces extensional stresses in the crust when the asthenospheric flow occurs from the thinner lithosphere towards the craton, defined here as the “cratonic bow”. On the other hand, compressional stresses in the crust are observed in the region where the asthenospheric flow occurs from the craton towards the thinner lithosphere, a portion defined here as the “cratonic stern”. The magnitude of the stresses increases with higher speeds and a thicker cratonic keel, reaching a magnitude of <mml:math altimg=\"si1.svg\" display=\"inline\"><mml:mrow><mml:mo>∼</mml:mo><mml:mspace width=\"-0.16667em\"></mml:mspace><mml:mn>10</mml:mn><mml:mspace width=\"0.33em\"></mml:mspace><mml:mi mathvariant=\"normal\">MPa</mml:mi></mml:mrow></mml:math> in the cratonic crust in the scenarios with a cratonic keel with 200 km in thickness. The asthenospheric flow under the cratonic keel induces edge-driven convection with larger vigor adjacent to the cratonic stern, where topographic perturbations are observed, especially in scenarios with a thick cratonic keel, resulting in negative dynamic topography of hundreds of meters. We propose that this mechanism of dynamic subsidence can explain part of the negative residual topography observed along the southern Australian margin, induced by the fast (<mml:math altimg=\"si2.svg\" display=\"inline\"><mml:mrow><mml:mo>∼</mml:mo><mml:mn>7</mml:mn><mml:mo>.</mml:mo><mml:mn>4</mml:mn></mml:mrow></mml:math> cm/year) northward movement of the plate combined with the presence of a thick lithospheric keel in the continent.","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"79 1","pages":"230865"},"PeriodicalIF":2.9,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144898138","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":"Along-strike variations in intermediate-depth seismicity in the southernmost Mariana subduction zone: Impact from the subduction of an oceanic plateau","authors":"Han Chen ,&nbsp;Gaohua Zhu ,&nbsp;Hongfeng Yang ,&nbsp;Jiangyang Zhang ,&nbsp;Shaopin Lu ,&nbsp;Chuanxu Chen ,&nbsp;Jian Lin ,&nbsp;Yiming Luo","doi":"10.1016/j.tecto.2025.230875","DOIUrl":"10.1016/j.tecto.2025.230875","url":null,"abstract":"<div><div>Intermediate-depth earthquakes, i.e., earthquakes occurring at depths of 60 to 300 km, have been observed globally. However, the mechanisms underlying intermediate-depth earthquakes and their potential relationship with shallow subduction zone structures are still poorly understood. Utilizing newly obtained near-field Ocean Bottom Seismometer (OBS) data and a machine-learning-based method (EQTransformer), we have detected and located 613 earthquakes from 5 September 2018 to 22 October 2019. The observation identifies the variations in the distribution patterns of intermediate-depth earthquakes at the junction of the Pacific plate and the Caroline Plateau. Double seismic zones (DSZs) were observed in the Pacific segment, while a single seismic zone (SSZ) was found in the Caroline segment. The consistency between observed seismicity patterns, tectonic geomorphology, outer-rise faulting, and slab P-T modeling strongly suggests intermediate-depth earthquakes are likely related to the dehydration of hydrous minerals. We propose that the seismicity difference between the two segments is attributed to the subducted oceanic plateau, which restricts hydration of the subducting plate thereby suppressing the generation of intermediate-depth earthquakes. Our results emphasize the important influence of oceanic plateau subduction in the generation and distribution of intermediate-depth earthquakes.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230875"},"PeriodicalIF":2.6,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827439","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":"Differential subsidence and gravity collapse of the eastern and western Niger Delta lobes: Evidence from 2-D kinematic structural modelling","authors":"Kelvin Ikenna Chima ,&nbsp;Estelle Leroux ,&nbsp;Marina Rabineau ,&nbsp;Didier Granjeon ,&nbsp;Maryline Moulin ,&nbsp;Philippe Schnurle ,&nbsp;Daniel Aslanian","doi":"10.1016/j.tecto.2025.230874","DOIUrl":"10.1016/j.tecto.2025.230874","url":null,"abstract":"<div><div>The Niger Delta prism is well-known and has been described as gravitationally deformed above an overpressured shale décollement, leading to complex geometries. However, it remains unclear whether failures were initiated simultaneously and propagated synchronously over time in the eastern and western parts of the delta. This study investigates this issue using backstripping and kinematic structural restoration of regional 2-D seismic cross-sections from the eastern and western Niger Delta lobes (ENDL and WNDL). Our results suggest that the Niger Delta is controlled by the interplay between gravitational collapse processes and the crustal architecture of a divergent margin. At the delta scale, gravitational extension typically exceeds gravitational contraction, with intervening overpressured shales partially accommodating strain. Gravitational contraction initiated earlier in the offshore ENDL (Early Messinian) compared to the offshore WNDL (Plio-Pleistocene), but the WNDL has been relatively more active and has spread faster than the ENDL. A dip in the ENDL basal décollement facilitated more basinward translation of the lobe, coupled with gravity spreading due to delta lobe progradation in the Late Tortonian. In contrast, the relatively gentle dip of the offshore WNDL's regional décollement, aided by depositional loading, favoured rapid gravity spreading of the lobe in the Plio-Pleistocene. Cross-section restoration suggests that the ENDL localizes subsidence on the modern shelf, while the WNDL shows homogeneous spatial subsidence. The inferred differential spatial subsidence along the ENDL and WNDL cross-sections could be linked to (i) differences in crustal architecture (oceanic versus intermediate) and/or (ii) differences in geodynamic location (strike-slip versus divergent setting).</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230874"},"PeriodicalIF":2.6,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827438","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 Totschunda-Denali intersection of Alaska: A low-angle (<25°) strike-slip fault intersection since at least ∼25 Ma","authors":"Jacob L. Rosenthal ,&nbsp;Jeff A. Benowitz ,&nbsp;Paul G. Fitzgerald ,&nbsp;Nicolas Perez-Consuegra ,&nbsp;James R. Metcalf ,&nbsp;Paul B. O'Sullivan","doi":"10.1016/j.tecto.2025.230873","DOIUrl":"10.1016/j.tecto.2025.230873","url":null,"abstract":"<div><div>Fault intersections are ubiquitous to strike-slip fault systems and can enable significant displacement when slip is transferred between splays over time during earthquake events. If and how these strike-slip fault intersections endure and evolve is an ongoing question in tectonics. The Cretaceous-aged and dextrally active sub-vertically dipping Totschunda and Denali faults of Alaska currently intersect at a low-angle (&lt;25°) and communicate slip as these faults transfer strain inboard from Alaska's southern convergent margin. However, when the Totschunda-Denali low-angle fault intersection formed, and how this junction has responded to far-field stress changes, is unconstrained. We apply geochronology (zircon U<img>Pb) and low-temperature thermochronology (zircon and apatite [U<img>Th]/He and apatite fission-track) with inverse thermal modeling to constrain the spatial-temporal cooling history of the crustal blocks around the Totschunda-Denali fault intersection. The block bounded within the apex of the Totschunda and Denali fault intersection (DENT block) began to rapidly cool (&gt;30 °C/Ma) by ∼25 Ma. The DENT block's late Oligocene-early Miocene cooling rate surpasses magnitudes in the palinspasticly restored surrounding blocks (&gt;10 °C/Ma vs ≤ ∼2 °C/Ma). We link the onset of ∼25 Ma DENT block rapid cooling with the probable existence of the fault intersection by this time, as both strands of the fault intersection had to be active and connected to accommodate vertical block extrusion and exhumation. Subsequently, late Miocene-Quaternary rapid cooling (&gt;6 °C/Ma) along the Totschunda fault occurs when this fault becomes the principal slip strand, which is linked to a change in the Pacific-Yakutat plate vector. The vertical extrusion of the DENT block and the switch to increased slip along the Totschunda fault post ∼6 Ma has enabled long-lived (≥25 Ma) geometric stability of this intersection, even during changes in relative convergence, by limiting fault system reorganization. Globally, low-angle (&lt;25°) strike-slip fault intersections are mechanically efficient and may endure for tens of millions of years.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"913 ","pages":"Article 230873"},"PeriodicalIF":2.6,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827441","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":"Rethinking the 1946 Chatkal earthquake: Contributions of Pléiades and UAV images to a surface-rupturing event along the Talas-Fergana Fault","authors":"Magali Rizza ,&nbsp;Léa Pousse ,&nbsp;Jules Fleury ,&nbsp;Clément Dubois ,&nbsp;Sultan Baikulov ,&nbsp;Kanatbek Abdrakhmatov","doi":"10.1016/j.tecto.2025.230863","DOIUrl":"10.1016/j.tecto.2025.230863","url":null,"abstract":"<div><div>This study re-evaluates the paleoseismicity and seismic hazard of the northern Talas-Fergana Fault (TFF), a major strike-slip fault in Central Asia, through geomorphic and paleoseismic investigations in the Chatkal Range. Although active during the late Holocene, the TFF's seismic behavior remains poorly understood. No major earthquakes have been definitively linked to it in instrumental or historical records, and paleoseismic data are scarce. The most significant regional event, the <em>Ms</em> 7.5 Chatkal earthquake of November 2, 1946, generated intense ground shaking, despite its epicenter being located approximately 20 to 70 km away from the Talas-Fergana Fault (TFF). Yet, no clear surface rupture or fresh tectonic scarps have been documented nearby, fueling ongoing debate over the fault source, location, and relation to the TFF. To resolve these uncertainties, we integrate remote sensing, high-resolution topographic analysis, field mapping, and trenching to identify and characterize surface faulting along the TFF. Satellite and drone imagery reveal a well-preserved rupture zone extending 32–55 km, with horizontal displacements of 4.8–6.5 m, values consistent with an earthquake of <em>Mw</em> 6.9–7.3, aligning well with the 1946 event. Trenching results indicate at least three surface-rupturing earthquakes over the past 6500 years and dating of a displaced alluvial fan yields slip rate of 0.9–1.8 mm/yr—substantially lower than values reported further south. These findings confirm that the TFF is capable of generating significant earthquakes. A key finding is that the 1946 rupture may have initiated on a subsidiary ENE-trending thrust fault before propagating onto the TFF—a slip-partitioned rupture model that reconciles surface rupture observations with relocated epicenters and mirrors behavior seen in other complex strike-slip fault systems. Our results point to segmented rupture patterns and the potential for <em>Mw</em> 6.5–7.5 earthquakes along the northern TFF, underscoring its importance for seismic hazard assessments in the region.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"912 ","pages":"Article 230863"},"PeriodicalIF":2.6,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767062","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 Cenozoic tectonic evolution of the Tengchong and Baoshan blocks, southeastern Tibetan Plateau: Insights from low-temperature thermochronology","authors":"Jiawen Jiang ,&nbsp;Chen Wu ,&nbsp;Jie Li ,&nbsp;Peter Haproff ,&nbsp;Guosheng Wang ,&nbsp;Xiaoming Shen ,&nbsp;Hao Wu ,&nbsp;Yu Xia","doi":"10.1016/j.tecto.2025.230866","DOIUrl":"10.1016/j.tecto.2025.230866","url":null,"abstract":"<div><div>The southeastern Tibetan Plateau has been a key area for Cenozoic deformation and orogenic expansion during India-Asia convergence. Yet, its tectonic and exhumation histories remain inadequately understood. In addition, significant debate has focused on whether lateral growth of the plateau was controlled by continental-scale, discrete faulting and/or lower crustal flow. To address these questions for the southeastern Tibetan Plateau, we performed field mapping and low-temperature thermochronology across the Tengchong and Baoshan blocks and along the Gaoligong and Chongshan shear zones. Cooling ages and thermal history models indicate that the region experienced at least four distinct cooling phases since the Miocene: ca. 18–10 Ma, ca. 7–5 Ma, and ca. 5–2 Ma. The Early to Middle Miocene (ca. 18–10 Ma) phase is characterized by greater and more rapid cooling and thus, dominated the exhumation history of the southeastern Tibetan Plateau margin. Ca. 18–10 Ma cooling is interpreted to be associated with oblique slip along the Gaoligong shear zone. Regional cooling from ca. 15–10 Ma was likely driven by lower crustal flow. Late Miocene (ca. 7–5 Ma) cooling was restricted to areas featuring deep river incision, suggesting influences from topography and enhanced erosion. Pliocene–early Pleistocene (ca. 5–2 Ma) cooling is linked to fault activity and volcanism associated with Indian slab dynamics beneath the Myanmar subduction zone. Our results also suggest that the lateral expansion of the southeastern Tibetan Plateau was driven by both continental-scale shear and lower-crustal flow rather than a singular dynamic mechanism.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"912 ","pages":"Article 230866"},"PeriodicalIF":2.6,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144763916","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":"Monitoring induced seismicity in the Weiyuan shale gas field utilizing a dense array","authors":"Lichun Yang ,&nbsp;Jinping Zi ,&nbsp;Ruijia Wang ,&nbsp;Hongfeng Yang","doi":"10.1016/j.tecto.2025.230862","DOIUrl":"10.1016/j.tecto.2025.230862","url":null,"abstract":"<div><div>Understanding the mechanisms of induced seismicity and assessing associated hazards is crucial for risk mitigation in shale gas production regions. From August 2022 to February 2023, we maintained a dense array of 245 nodal stations with an average spacing of ∼3 km, covering the entire Weiyuan shale gas field (WSGF), an actively exploited region that has experienced induced earthquakes up to <em>M</em>_<em>w</em> 5.0. Using the LOC-FLOW, we constructed a high-resolution earthquake catalog, precisely locating 29,669 events ranging from <em>M</em>_<em>L</em> − 1.35 to <em>M</em>_<em>L</em> 3.42 with a completeness magnitude (<em>M</em>_<em>c</em>) of −0.24. Seismicity formed five distinct clusters, with those in the southern WSGF closely surrounding hydraulic fracturing wells and exhibiting migration patterns consistent with pore-pressure diffusion. In contrast, northern seismicity displayed characteristics of fault reactivation, with events aligning with pre-existing geological structures. Additionally, we observed persistent seismic activity near the epicenter of 2019 <em>M</em>_<em>w</em> 5.0 event, suggesting a long-lasting aftershock sequence. Our findings emphasize the necessity of high-resolution seismic monitoring and long-term hazard assessment in shale gas fields. The results contribute to a better understanding of injection-induced seismicity and fault activation processes, providing valuable insights for risk mitigation and sustainable resource production in tectonically sensitive regions.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"912 ","pages":"Article 230862"},"PeriodicalIF":2.6,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750071","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 structure of the North Svalbard margin: Continental breakup and Eurasia Basin opening","authors":"Juan Camilo Meza-Cala ,&nbsp;Jan Inge Faleide ,&nbsp;Alexander Minakov ,&nbsp;Mansour M. Abdelmalak ,&nbsp;Grace E. Shephard ,&nbsp;Wolfram H. Geissler ,&nbsp;Peter Klitzke ,&nbsp;Rune Mattingsdal ,&nbsp;Carmen Gaina","doi":"10.1016/j.tecto.2025.230861","DOIUrl":"10.1016/j.tecto.2025.230861","url":null,"abstract":"<div><div>Continental breakup at the North Svalbard margin and the northern Barents Sea during the Paleogene led to the opening of the oceanic Eurasia Basin. However, the mechanisms behind this rift-to-drift evolution remain unclear. Here, we present seven crustal transects (CT1–7) integrating 2D forward modelling of potential field data and constrained by structural interpretation of multichannel seismic reflection profiles. These transects extend from the continental regions of North Svalbard to the oceanic domain in southwest Eurasia Basin. The Yermak Plateau comprises two juxtaposed tectono-magmatic blocks: the Northeast Yermak Plateau, linked to pre- or early Eurekan settings, and the Southwest Yermak Plateau, formed by shearing and oblique extension along the West Svalbard margin. Broadly, the North Svalbard margin is divided into three segments: (1) Northwest Spitsbergen-Southwest Yermak Plateau, (2) Northeast Spitsbergen-Northwest Kvitøya, and (3) Northeast Kvitøya-North Barents. Segmentation follows inherited north-northwest trending weak zones, guiding Paleogene multi-phase oblique rifting and formation of the Sophia Basin, underlain by thinned, high-density metamorphic crust. The results indicate a rift-shear breakup mode with exhumation of continental lower crust and/or serpentinized subcontinental mantle blocks within the continent-ocean transition (COT) that precedes seafloor spreading which started at ca. 53 Ma during magnetic chron C24. The continental breakup processes that led to margin segmentation reflect the interplay between inherited basement fabrics and plate opening directions of the Eurasia Basin region.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"912 ","pages":"Article 230861"},"PeriodicalIF":2.6,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144772647","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}