Pub Date : 2025-12-31DOI: 10.1016/j.tecto.2025.231064
Yan Xu, Shunping Pei, Xinhua Jia, Chaodi Xie, Mingrui Huang
Two intermediate-depth earthquakes with moment magnitude 5.8 and 5.3 respectively occurred in the Pamir-Hindu Kush in August 2023. We select three subarrays that exhibit a two-dimensional delta-shaped array response function from a temporary regional short-period array. For each event/subarray pair, the data is slant-stacked and normalized with respect to the initial p phase. Two secondary arrivals, P410p and s140p, bring out the information of the upper mantle beneath Pamir-Hindu Kush area. The reflection depth of the P-wave from the 410-km discontinuity suggests that the subducted cold slab of the Hindu Kush penetrates the discontinuity, uplifting it to a shallower depth as the reflection point approaches the cold core. The deepening trend of the reflection depth along the strike of the Pamir slab is consistent with the model that suggests the splitting of the subducted Pamir slab with its western part abutting against the Hindu Kush slab below 350 km. Our data provide a direct sampling of the boundary zone between the abutted Pamir-Hindu Kush slab and the normal mantle material. We observe a P wave, s140p, that was converted from an upgoing S wave at a depth of 140 km. This s140p phase exhibits a rapid drop in energy within a spatially confined, northwest-southeast oriented area, suggesting a near-vertical velocity boundary.
{"title":"Detailed structure of upper mantle discontinuities beneath the Pamir-Hindu Kush from the short period regional seismic array","authors":"Yan Xu, Shunping Pei, Xinhua Jia, Chaodi Xie, Mingrui Huang","doi":"10.1016/j.tecto.2025.231064","DOIUrl":"10.1016/j.tecto.2025.231064","url":null,"abstract":"<div><div>Two intermediate-depth earthquakes with moment magnitude 5.8 and 5.3 respectively occurred in the Pamir-Hindu Kush in August 2023. We select three subarrays that exhibit a two-dimensional delta-shaped array response function from a temporary regional short-period array. For each event/subarray pair, the data is slant-stacked and normalized with respect to the initial <em>p</em> phase. Two secondary arrivals, <em>P</em>410<em>p</em> and <em>s</em>140<em>p</em>, bring out the information of the upper mantle beneath Pamir-Hindu Kush area. The reflection depth of the P-wave from the 410-km discontinuity suggests that the subducted cold slab of the Hindu Kush penetrates the discontinuity, uplifting it to a shallower depth as the reflection point approaches the cold core. The deepening trend of the reflection depth along the strike of the Pamir slab is consistent with the model that suggests the splitting of the subducted Pamir slab with its western part abutting against the Hindu Kush slab below 350 km. Our data provide a direct sampling of the boundary zone between the abutted Pamir-Hindu Kush slab and the normal mantle material. We observe a P wave, <em>s</em>140<em>p</em>, that was converted from an upgoing S wave at a depth of 140 km. This <em>s</em>140<em>p</em> phase exhibits a rapid drop in energy within a spatially confined, northwest-southeast oriented area, suggesting a near-vertical velocity boundary.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231064"},"PeriodicalIF":2.6,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894945","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}
Pub Date : 2025-12-30DOI: 10.1016/j.tecto.2025.231056
Hamidreza Farkiani, Meysam Mahmoodabadi, Farzam Yaminifard, Mohammad Tatar
The Iranian Plateau, shaped by the ongoing collision between the Arabian and Eurasian plates, holds a geodynamically significant position within the Alpine-Himalayan belt. Investigating its deformation sheds light on its unique and complex role within this tectonic framework. The subduction of the Neotethys Ocean during this convergence has driven distributed shortening in the Zagros region, giving rise to diverse geological features such as metamorphic zones, magmatic arcs, crushed and elevated areas, sedimentary basins, and fold belts. This study aims to improve our understanding of crustal anisotropy and crustal thickness in the Zagros region. By processing seismic records from regional stations, we have characterized crustal deformation in the upper and lower crust using a two-stage approach. First, the generalized H--c stacking method was employed to estimate the Moho depth, ratio (), integrated crustal anisotropy, and Moho dip. The thickest crustal sections were identified beneath the northern part of the Sanandaj-Sirjan metamorphic zone (SSZ). Then, a layer-by-layer anisotropy analysis was conducted using curve-fitting techniques on converted Ps phases while accounting for the influence of overlying layers. This revealed distinct anisotropic properties in the upper and lower crust at most seismic stations. Comparing these deformation patterns with prior studies enhances our understanding of both shallow and deep crustal faults. Key findings include evidence of SPO (shape-preferred orientation) in the upper crust, LPO (lattice-preferred orientation) in the lower crust, a lack of vertically coherent integrated crustal anisotropy, potential slab breakoff in northern Zagros, and underthrusting in central and southern Zagros. These results provide fresh insights into the complex tectonic evolution of the Zagros region.
{"title":"Crustal anisotropy and deformation in the Zagros collision belt","authors":"Hamidreza Farkiani, Meysam Mahmoodabadi, Farzam Yaminifard, Mohammad Tatar","doi":"10.1016/j.tecto.2025.231056","DOIUrl":"10.1016/j.tecto.2025.231056","url":null,"abstract":"<div><div>The Iranian Plateau, shaped by the ongoing collision between the Arabian and Eurasian plates, holds a geodynamically significant position within the Alpine-Himalayan belt. Investigating its deformation sheds light on its unique and complex role within this tectonic framework. The subduction of the Neotethys Ocean during this convergence has driven distributed shortening in the Zagros region, giving rise to diverse geological features such as metamorphic zones, magmatic arcs, crushed and elevated areas, sedimentary basins, and fold belts. This study aims to improve our understanding of crustal anisotropy and crustal thickness in the Zagros region. By processing seismic records from regional stations, we have characterized crustal deformation in the upper and lower crust using a two-stage approach. First, the generalized H-<span><math><mi>κ</mi></math></span>-c stacking method was employed to estimate the Moho depth, <span><math><mfrac><msub><mi>V</mi><mi>P</mi></msub><msub><mi>V</mi><mi>S</mi></msub></mfrac></math></span> ratio (<span><math><mi>κ</mi></math></span>), integrated crustal anisotropy, and Moho dip. The thickest crustal sections were identified beneath the northern part of the Sanandaj-Sirjan metamorphic zone (SSZ). Then, a layer-by-layer anisotropy analysis was conducted using curve-fitting techniques on converted Ps phases while accounting for the influence of overlying layers. This revealed distinct anisotropic properties in the upper and lower crust at most seismic stations. Comparing these deformation patterns with prior studies enhances our understanding of both shallow and deep crustal faults. Key findings include evidence of SPO (shape-preferred orientation) in the upper crust, LPO (lattice-preferred orientation) in the lower crust, a lack of vertically coherent integrated crustal anisotropy, potential slab breakoff in northern Zagros, and underthrusting in central and southern Zagros. These results provide fresh insights into the complex tectonic evolution of the Zagros region.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231056"},"PeriodicalIF":2.6,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886456","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}
Pub Date : 2025-12-29DOI: 10.1016/j.tecto.2025.231057
Shaobo Han , Xiaoying Zhuang , Wei Feng , Quanzhou Yao , Qianlong Zhou , Xiaodong Hu
Rock heterogeneity and fluids are widespread in natural fault zones. How they interplay to affect fault strength and frictional stability remains inadequately understood, particularly taking fluid diffusion into account. Here, we develop a two-degree-of-freedom spring-slider model based on rate-and-state friction (RSF) to investigate the frictional behavior of heterogeneous faults including quartz- and clay-rich gouges. Our model incorporates lateral fluid diffusion and pore pressure interactions between two fault gouge segments. Our results show that the increase in clay content within a quartz-rich fault causes a progressive weakening in fault strength and enhanced frictional stability. In quartz-dominated faults, high hydraulic diffusivity significantly delays the initiation of stick-slip instabilities. Our results replicate a full spectrum of slip behaviors from stable creep, slow slip, to dynamic rupture with controlled fault composition, friction parameter ratios and fluid diffusivity properties. We demonstrate that pore pressure perturbations, especially inter-patch pressure differences under fluid diffusion conditions, can drive slip behavior transitions. Our findings provide a physical framework for understanding seismic and aseismic slip behavior in fluid-rich, heterogeneous subduction-zone fault gouges.
{"title":"Frictional strength and stability of laterally heterogeneous faults under fluid diffusion conditions","authors":"Shaobo Han , Xiaoying Zhuang , Wei Feng , Quanzhou Yao , Qianlong Zhou , Xiaodong Hu","doi":"10.1016/j.tecto.2025.231057","DOIUrl":"10.1016/j.tecto.2025.231057","url":null,"abstract":"<div><div>Rock heterogeneity and fluids are widespread in natural fault zones. How they interplay to affect fault strength and frictional stability remains inadequately understood, particularly taking fluid diffusion into account. Here, we develop a two-degree-of-freedom spring-slider model based on rate-and-state friction (RSF) to investigate the frictional behavior of heterogeneous faults including quartz- and clay-rich gouges. Our model incorporates lateral fluid diffusion and pore pressure interactions between two fault gouge segments. Our results show that the increase in clay content within a quartz-rich fault causes a progressive weakening in fault strength and enhanced frictional stability. In quartz-dominated faults, high hydraulic diffusivity significantly delays the initiation of stick-slip instabilities. Our results replicate a full spectrum of slip behaviors from stable creep, slow slip, to dynamic rupture with controlled fault composition, friction parameter ratios and fluid diffusivity properties. We demonstrate that pore pressure perturbations, especially inter-patch pressure differences under fluid diffusion conditions, can drive slip behavior transitions. Our findings provide a physical framework for understanding seismic and aseismic slip behavior in fluid-rich, heterogeneous subduction-zone fault gouges.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231057"},"PeriodicalIF":2.6,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886488","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}
Pub Date : 2025-12-26DOI: 10.1016/j.tecto.2025.231058
Daniel Phillips , Daniel Roberts , Martino Foschi , Ben Aldridge , Joe Cartwright
Salt has the unique ability to flow on geological timescales in response to even low differential stresses. This has facilitated the formation of complex structures in many sedimentary basins globally. Since many salt basins experience multiple deformational phases after deposition, disentangling the key drivers of deformation is often challenging. Here, we use basin-scale numerical modelling focusing on the geological creep of salt in order to recreate displaced fluid escape pipes acting as kinematic markers in the Eastern Mediterranean. We use a parameter sweep to demonstrate that a numerical solution of the maximum horizontal pipe displacement is contained within realistic values of basinal tilt and evaporite rheologies. Optimal modelled flow profiles were found to be parabolic, with lower viscosity models tending to a sigmoidal solution and higher viscosity models tending to a laminar linear solution. There are significant discrepancies between model-derived flow profiles and idealised Couette flow, which may lead to challenges regarding prior bulk flow reconstructions. These results are uniquely observationally constrained, and provide insights into the driving forces behind basin-scale salt flow, along with the stress evolution of basins and the nature of passive strain markers within evaporite sequences.
{"title":"Finite element modelling of evaporite flow constrained by kinematic markers in the Messinian of the Eastern Mediterranean","authors":"Daniel Phillips , Daniel Roberts , Martino Foschi , Ben Aldridge , Joe Cartwright","doi":"10.1016/j.tecto.2025.231058","DOIUrl":"10.1016/j.tecto.2025.231058","url":null,"abstract":"<div><div>Salt has the unique ability to flow on geological timescales in response to even low differential stresses. This has facilitated the formation of complex structures in many sedimentary basins globally. Since many salt basins experience multiple deformational phases after deposition, disentangling the key drivers of deformation is often challenging. Here, we use basin-scale numerical modelling focusing on the geological creep of salt in order to recreate displaced fluid escape pipes acting as kinematic markers in the Eastern Mediterranean. We use a parameter sweep to demonstrate that a numerical solution of the maximum horizontal pipe displacement is contained within realistic values of basinal tilt and evaporite rheologies. Optimal modelled flow profiles were found to be parabolic, with lower viscosity models tending to a sigmoidal solution and higher viscosity models tending to a laminar linear solution. There are significant discrepancies between model-derived flow profiles and idealised Couette flow, which may lead to challenges regarding prior bulk flow reconstructions. These results are uniquely observationally constrained, and provide insights into the driving forces behind basin-scale salt flow, along with the stress evolution of basins and the nature of passive strain markers within evaporite sequences.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231058"},"PeriodicalIF":2.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842551","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}
Pub Date : 2025-12-26DOI: 10.1016/j.tecto.2025.231060
Mustapha Bouiflane , Ahmed Manar
Two long NE-trending doleritic dykes are found cropping out in the Anti-Atlas Mountains. The the Foum Zguid dyke has generated wide interest in geological research because considered as one of the best-preserved products of the Central Atlantic Magmatic Province. However, the Ighrem dyke remains relatively less explored owing to the paucity of unaltered rock exposures. In this contribution, we investigate the Igherm dyke from analysis and interpretation of new high-resolution aeromagnetic data to follow its trace and prolongation over large areas lacking surface exposure. Geological interpretation results highlight the geophysical signature of the Igherm dyke which allowed us to propose an updated map of the dyke. This map shows the dyke prolongation farther to the northeast as well as towards the southwest spreading over 270 km. Moreover, the Igherm dyke appears to be fragmented into multiple segments with varying morphology most of them do not reach the surface and reveals a number of different segmentation structures in many locations of the relays between adjacent segments. According to the magmatic and tectonic settings of the Anti-Atlas, we consider that the emplacement of the Ighrem dyke is mainly driven by structural control of pre-existing fractures. However, we assume that additional factors, such as regional structural patterns, change in both the local and the regional stress fields, magma flow conditions and host rock heterogeneities may play roles in whether the intrusion of the dyke reach the surface or be arrested at various crustal levels but also controlling the geometrical form of the dyke.
{"title":"Updated map and insights into emplacement conditions of Ighrem doleritic dyke (Anti-Atlas Mountains, Morocco)","authors":"Mustapha Bouiflane , Ahmed Manar","doi":"10.1016/j.tecto.2025.231060","DOIUrl":"10.1016/j.tecto.2025.231060","url":null,"abstract":"<div><div>Two long NE-trending doleritic dykes are found cropping out in the Anti-Atlas Mountains. The the Foum Zguid dyke has generated wide interest in geological research because considered as one of the best-preserved products of the Central Atlantic Magmatic Province. However, the Ighrem dyke remains relatively less explored owing to the paucity of unaltered rock exposures. In this contribution, we investigate the Igherm dyke from analysis and interpretation of new high-resolution aeromagnetic data to follow its trace and prolongation over large areas lacking surface exposure. Geological interpretation results highlight the geophysical signature of the Igherm dyke which allowed us to propose an updated map of the dyke. This map shows the dyke prolongation farther to the northeast as well as towards the southwest spreading over 270 km. Moreover, the Igherm dyke appears to be fragmented into multiple segments with varying morphology most of them do not reach the surface and reveals a number of different segmentation structures in many locations of the relays between adjacent segments. According to the magmatic and tectonic settings of the Anti-Atlas, we consider that the emplacement of the Ighrem dyke is mainly driven by structural control of pre-existing fractures. However, we assume that additional factors, such as regional structural patterns, change in both the local and the regional stress fields, magma flow conditions and host rock heterogeneities may play roles in whether the intrusion of the dyke reach the surface or be arrested at various crustal levels but also controlling the geometrical form of the dyke.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231060"},"PeriodicalIF":2.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145845308","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}
Pub Date : 2025-12-26DOI: 10.1016/j.tecto.2025.231059
Liang Jin , Jie Liu , Sanzhong Li , Yanhui Suo , Pengcheng Wang , Junjiang Zhu
Located in the collision zone between the Eurasian and Philippine Sea plates, the Philippine Mobile Belt (PMB), with intense earthquakes and volcanism, is a typical area for the study of plate subduction, island arc accretion, and microplate amalgamation. However, due to the complexity of tectonic history of this region, the existing studies are still deficient in understanding the crustal structure and deep dynamics. To address this, we develop a new improved crustal thickness model for the Philippine Archipelago using EIGEN-6C4 gravity data and advanced inversion methodology. Integration of microplate boundary kinematics and active fault systems permits division of the PMB into nine discrete microplates. Our study shows that pronounced isostatic disequilibrium along the Manila Trench, Philippine Trench, and Philippine Fault, indicating active lithospheric adjustment. The crustal thickness of the PMB shows significant spatial heterogeneity, revealing the existence of anomalous crustal thickening spatially correlated with volcanic chains flanking the main Philippine Fault Zone. We propose a dual-mechanism crustal thickening model driven by both multi-stage accretionary processes and deep magma underplating, offering new insights into the crust-mantle interactions governing the Philippine orogenic system and microplate geodynamics.
{"title":"Gravity-derived crustal thickness heterogeneity in the Philippine Archipelago: Implications for a new microplate framework","authors":"Liang Jin , Jie Liu , Sanzhong Li , Yanhui Suo , Pengcheng Wang , Junjiang Zhu","doi":"10.1016/j.tecto.2025.231059","DOIUrl":"10.1016/j.tecto.2025.231059","url":null,"abstract":"<div><div>Located in the collision zone between the Eurasian and Philippine Sea plates, the Philippine Mobile Belt (PMB), with intense earthquakes and volcanism, is a typical area for the study of plate subduction, island arc accretion, and microplate amalgamation. However, due to the complexity of tectonic history of this region, the existing studies are still deficient in understanding the crustal structure and deep dynamics. To address this, we develop a new improved crustal thickness model for the Philippine Archipelago using EIGEN-6C4 gravity data and advanced inversion methodology. Integration of microplate boundary kinematics and active fault systems permits division of the PMB into nine discrete microplates. Our study shows that pronounced isostatic disequilibrium along the Manila Trench, Philippine Trench, and Philippine Fault, indicating active lithospheric adjustment. The crustal thickness of the PMB shows significant spatial heterogeneity, revealing the existence of anomalous crustal thickening spatially correlated with volcanic chains flanking the main Philippine Fault Zone. We propose a dual-mechanism crustal thickening model driven by both multi-stage accretionary processes and deep magma underplating, offering new insights into the crust-mantle interactions governing the Philippine orogenic system and microplate geodynamics.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231059"},"PeriodicalIF":2.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145845307","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}
Pub Date : 2025-12-24DOI: 10.1016/j.tecto.2025.231055
Gang Zhang , Yongjie Tang , Xuben Wang , Yu Ma , Yushu Tang , Chao Zhang
The Kangding geothermal field in western China, despite abundant high-temperature resources, has low utilization (<8 %) due to unclear deep genesis models. This study used magnetotelluric (MT) data from 30 stations along a 140 km profile, combined with 3D inversion, to build a deep electrical conductivity model. By integrating electrical conductivity-temperature relationships and heat conduction equations, it further developed thermal structure and rock partial melting models. The study also analyzed crustal heat flow, Moho depth, and tectonic dynamics to explore deep thermo-tectonic mechanisms. Key findings include: (1) A “high-low-high” crustal electrical structure with low-resistivity zones (20–50 km depth) indicating eastward crustal flow; (2) High temperatures (>850 °C), water content (1–7 wt%), and partial melting (1–10 %, up to >10 % in core areas) as major heat sources; (3) The Xianshuihe Fault as a deep-seated fracture enabling strike-slip heat generation and fluid transfer; (4) A geothermal system integrating mid-lower crustal heat, fault friction, and precipitation recharge. These insights enhance understanding of Kangding's geothermal activity, supporting improved resource assessment. Acknowledging parameter limitations, this study adopted a geophysically validated conductivity-temperature method, which may cause minor model-prediction discrepancies compared to actual conditions.
{"title":"Deep electrical structure and thermodynamic mechanism of the high-temperature geothermal field in Kangding, Western Sichuan, China","authors":"Gang Zhang , Yongjie Tang , Xuben Wang , Yu Ma , Yushu Tang , Chao Zhang","doi":"10.1016/j.tecto.2025.231055","DOIUrl":"10.1016/j.tecto.2025.231055","url":null,"abstract":"<div><div>The Kangding geothermal field in western China, despite abundant high-temperature resources, has low utilization (<8 %) due to unclear deep genesis models. This study used magnetotelluric (MT) data from 30 stations along a 140 km profile, combined with 3D inversion, to build a deep electrical conductivity model. By integrating electrical conductivity-temperature relationships and heat conduction equations, it further developed thermal structure and rock partial melting models. The study also analyzed crustal heat flow, Moho depth, and tectonic dynamics to explore deep thermo-tectonic mechanisms. Key findings include: (1) A “high-low-high” crustal electrical structure with low-resistivity zones (20–50 km depth) indicating eastward crustal flow; (2) High temperatures (>850 °C), water content (1–7 wt%), and partial melting (1–10 %, up to >10 % in core areas) as major heat sources; (3) The Xianshuihe Fault as a deep-seated fracture enabling strike-slip heat generation and fluid transfer; (4) A geothermal system integrating mid-lower crustal heat, fault friction, and precipitation recharge. These insights enhance understanding of Kangding's geothermal activity, supporting improved resource assessment. Acknowledging parameter limitations, this study adopted a geophysically validated conductivity-temperature method, which may cause minor model-prediction discrepancies compared to actual conditions.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231055"},"PeriodicalIF":2.6,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823481","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}
Pub Date : 2025-12-22DOI: 10.1016/j.tecto.2025.231054
Min Feng , Juzhi Deng , Hui Yu , Hui Chen , Yunong Wei , Yanguo Wang , Xiao Chen
The intraplate volcanic system in Xiangshan basin provides the main source of ore-forming materials for the world's third-largest volcanogenic uranium deposit. Although geological evidence suggests the existence of two volcanic cycles, the geometries of complete volcanic systems remain enigmatic and are not fully understood, as are the underlying emplacements responsible, due in part to the lack of sufficient geophysical data. To refine the structure of the volcanic system, we applied a gravity-magnetic joint inversion constrained by the resistivity model. The results delineated the first volcanic cycle rhyodacite conduit beneath the Shutang area in the western basin, characterized by high susceptibility and dipping southwest in the shallow subsurface, with its emplacement controlled by a low-density east–west-trending basement fault activated by regional north-south extension stresses. The second volcanic cycle porphyroclastic lava conduit, characterized by low density and high susceptibility, dips southeastward and extends toward the northeast flank of Mount Xiangshan. In the west, the high susceptibility of the first-cycle volcanic conduit suggests that the second-cycle porphyroclastic lava conduit may have inherited the earlier magmatic pathway, with its emplacement jointly controlled by low-density regional north–south basement faults activated by east–west extension stresses and pre-existing east–west structures. These results underscore the dominant role of regional tectonic environments in controlling the multi volcanic cycles and provide new insight for emplacement mechanisms in a strike-slip extension environment.
{"title":"The emplacement of an intraplate volcanic system in the Xiangshan Basin, Southeast China, implied from resistivity constrained 3D gravity and magnetic joint inversion","authors":"Min Feng , Juzhi Deng , Hui Yu , Hui Chen , Yunong Wei , Yanguo Wang , Xiao Chen","doi":"10.1016/j.tecto.2025.231054","DOIUrl":"10.1016/j.tecto.2025.231054","url":null,"abstract":"<div><div>The intraplate volcanic system in Xiangshan basin provides the main source of ore-forming materials for the world's third-largest volcanogenic uranium deposit. Although geological evidence suggests the existence of two volcanic cycles, the geometries of complete volcanic systems remain enigmatic and are not fully understood, as are the underlying emplacements responsible, due in part to the lack of sufficient geophysical data. To refine the structure of the volcanic system, we applied a gravity-magnetic joint inversion constrained by the resistivity model. The results delineated the first volcanic cycle rhyodacite conduit beneath the Shutang area in the western basin, characterized by high susceptibility and dipping southwest in the shallow subsurface, with its emplacement controlled by a low-density east–west-trending basement fault activated by regional north-south extension stresses. The second volcanic cycle porphyroclastic lava conduit, characterized by low density and high susceptibility, dips southeastward and extends toward the northeast flank of Mount Xiangshan. In the west, the high susceptibility of the first-cycle volcanic conduit suggests that the second-cycle porphyroclastic lava conduit may have inherited the earlier magmatic pathway, with its emplacement jointly controlled by low-density regional north–south basement faults activated by east–west extension stresses and pre-existing east–west structures. These results underscore the dominant role of regional tectonic environments in controlling the multi volcanic cycles and provide new insight for emplacement mechanisms in a strike-slip extension environment.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231054"},"PeriodicalIF":2.6,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145813957","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}
Pub Date : 2025-12-22DOI: 10.1016/j.tecto.2025.231053
Chutong Chen , Na Li , Lingxiao Zhang , Hongying An , Chang’an Guo , Xing Fu , Songda Lei , Guicai Yang , Junjie Fan , Weiheng Yuan , Hao Wang , Bin Wang , Kunpeng Wang
The Alxa and Beishan domains experienced extensive arc-related magmatism during the closure of the Paleo Asian Ocean, followed by long-lived intracontinental deformation. Widespread sedimentation has obscured their deep structures and mutual relations. Here we integrate gravity, magnetic, and magnetotelluric data to refine the crustal structures and evaluate the tectonic linkage between the Alxa and Beishan domains. Geophysical contrasts across the Quagan Qulu–Tebai suture identify it as a major lithospheric boundary, separating accretionary complexes in the north from continental lithosphere in the south. In southern Alxa, magnetic and gravity anomalies delineate two concealed early Permian arc belts, whose spatial alignment with ductile strike-slip zones suggests their localization along lithospheric weaknesses during post-collisional transpression. Across the Alxa–Beishan boundary, east–west ophiolitic magnetic highs are not directly continuous. Northeast-trending faults, including the Sanweishan and Ruoshui faults, disrupt the boundary, and the gravity field indicates a discontinuous rather than uniform crustal architecture. These geophysical observations support the view that a direct connection between the Alxa and Beishan is unlikely. The Sanweishan fault is identified as a crustal-scale structure that, together with the Xingxingxia and Ruoshui faults, forms a major fault system distributed in the Beishan domain. Collectively, these results highlight segmented tectonic domains and largely independent Mesozoic deformation in Alxa and Beishan, offering new geophysical constraints on their crustal architecture and mutual tectonic linkage.
{"title":"Crustal structure and tectonic implications of the Southern Central Asian Orogenic Belt: New insights from gravity, magnetic, and magnetotelluric imaging","authors":"Chutong Chen , Na Li , Lingxiao Zhang , Hongying An , Chang’an Guo , Xing Fu , Songda Lei , Guicai Yang , Junjie Fan , Weiheng Yuan , Hao Wang , Bin Wang , Kunpeng Wang","doi":"10.1016/j.tecto.2025.231053","DOIUrl":"10.1016/j.tecto.2025.231053","url":null,"abstract":"<div><div>The Alxa and Beishan domains experienced extensive arc-related magmatism during the closure of the Paleo Asian Ocean, followed by long-lived intracontinental deformation. Widespread sedimentation has obscured their deep structures and mutual relations. Here we integrate gravity, magnetic, and magnetotelluric data to refine the crustal structures and evaluate the tectonic linkage between the Alxa and Beishan domains. Geophysical contrasts across the Quagan Qulu–Tebai suture identify it as a major lithospheric boundary, separating accretionary complexes in the north from continental lithosphere in the south. In southern Alxa, magnetic and gravity anomalies delineate two concealed early Permian arc belts, whose spatial alignment with ductile strike-slip zones suggests their localization along lithospheric weaknesses during post-collisional transpression. Across the Alxa–Beishan boundary, east–west ophiolitic magnetic highs are not directly continuous. Northeast-trending faults, including the Sanweishan and Ruoshui faults, disrupt the boundary, and the gravity field indicates a discontinuous rather than uniform crustal architecture. These geophysical observations support the view that a direct connection between the Alxa and Beishan is unlikely. The Sanweishan fault is identified as a crustal-scale structure that, together with the Xingxingxia and Ruoshui faults, forms a major fault system distributed in the Beishan domain. Collectively, these results highlight segmented tectonic domains and largely independent Mesozoic deformation in Alxa and Beishan, offering new geophysical constraints on their crustal architecture and mutual tectonic linkage.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"921 ","pages":"Article 231053"},"PeriodicalIF":2.6,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823483","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}
Pub Date : 2025-12-22DOI: 10.1016/j.tecto.2025.231052
Marianela Lupari , Héctor P.A. García , Silvina Nacif , Andrés Folguera , Francisco Ruiz
This study focuses on the central sector of the Malargüe Fold and Thrust Belt (35.5°–36.5°S), where the limited crustal seismicity of the Payenia volcanic field and the presence of Quaternary deposits complicate the delineation of the neotectonic front and the identification of active structures. The deployment of a seismological network enabled the recording of local seismicity, revealing hypocenters clustered into two main groups in the upper crust, associated with NE–SW oriented basement structures. Focal mechanism analysis indicates a predominance of dextral strike-slip faulting with subordinate reverse components, while gravity data link the earthquakes to the source bodies generating the main anomalies. Group A activity reflects deformation accommodated by dextral basement faults modulated by reverse motion, with implications for hydrocarbon migration and accumulation. Group B highlights the interaction between deep structures, upper-crustal anisotropies, and active magmatic processes beneath the Payún Matrú volcano. These findings suggest that both inherited structures and mantle-related thermal anomalies (SWAP) govern stress distribution and seismicity in the region.
{"title":"Definition of the Andean seismogenic-active front in the Malargüe fold and thrust belt using a local seismic network and gravity data","authors":"Marianela Lupari , Héctor P.A. García , Silvina Nacif , Andrés Folguera , Francisco Ruiz","doi":"10.1016/j.tecto.2025.231052","DOIUrl":"10.1016/j.tecto.2025.231052","url":null,"abstract":"<div><div>This study focuses on the central sector of the Malargüe Fold and Thrust Belt (35.5°–36.5°S), where the limited crustal seismicity of the Payenia volcanic field and the presence of Quaternary deposits complicate the delineation of the neotectonic front and the identification of active structures. The deployment of a seismological network enabled the recording of local seismicity, revealing hypocenters clustered into two main groups in the upper crust, associated with NE–SW oriented basement structures. Focal mechanism analysis indicates a predominance of dextral strike-slip faulting with subordinate reverse components, while gravity data link the earthquakes to the source bodies generating the main anomalies. Group A activity reflects deformation accommodated by dextral basement faults modulated by reverse motion, with implications for hydrocarbon migration and accumulation. Group B highlights the interaction between deep structures, upper-crustal anisotropies, and active magmatic processes beneath the Payún Matrú volcano. These findings suggest that both inherited structures and mantle-related thermal anomalies (SWAP) govern stress distribution and seismicity in the region.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231052"},"PeriodicalIF":2.6,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823482","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}
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