Tectonophysics最新文献_第5页

From fabric to process: An integrated study of deformed quartz-rich carbonates 从织物到工艺：变形富石英碳酸盐的综合研究

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-26 Epub Date: 2025-12-11 DOI: 10.1016/j.tecto.2025.231034

Maria Eleni Taxopoulou , Marine Lartigau , Charles Aubourg , Nicolas E. Beaudoin , Elli-Maria Charalampidou , Jean Paul Callot

This study investigates the presence and nature of diffuse deformation in a low-porosity carbonate rock that underwent polyphase tectonics and contains a network of veins, tectonic stylolites, and deformation bands. By using a non-destructive methodology based on Electron Backscatter Diffraction, X-ray computed tomography, coupled with results from Anisotropy of Magnetic Susceptibility and the Fry technique, we examine the grain fabric and strain distribution within the rock. Our investigation reveals evidence of quartz reorientation with respect to the polyphase contractional history of the area. Several mechanisms of quartz reorientation were proposed, including rigid reorientation during rotation and diffusion-related processes. The coexistence of ductile and brittle deformation mechanisms in the carbonate matrix indicates a complex response to compaction which can be recorded by the matrix, but does not appear to have a direct effect on the actual amount of shortening, as this is predominantly affected by the deformation bands. Our findings highlight the complexity of strain accommodation, with diffuse deformation creating subtle variations in grain size, shape, and orientation within the carbonate matrix. The study enhances our understanding of deformation processes in poly-deformed carbonate rocks and provides valuable insights into the geological context of the studied locations, by using a novel technique that can be useful for gaining qualitative and quantitative information from the rock samples. However, linking specific reorientation mechanisms to individual tectonic events remains challenging due to the multifaceted nature of deformation processes operating over different magnitudes and timescales.

本文研究了低孔隙度碳酸盐岩中弥漫性变形的存在和性质，该碳酸盐岩经历了多期构造，包含脉体、构造柱岩和变形带网络。通过使用基于电子背散射衍射、x射线计算机断层扫描的无损方法，结合磁化率各向异性和Fry技术的结果，我们研究了岩石内部的颗粒结构和应变分布。我们的研究揭示了该地区多相收缩历史中石英重新定向的证据。提出了石英重定向的几种机制，包括旋转过程中的刚性重定向和扩散过程中的刚性重定向。碳酸盐基质中韧性和脆性变形机制的共存表明了对压实的复杂响应，这可以被基质记录下来，但似乎对实际的缩短量没有直接影响，因为这主要受变形带的影响。我们的研究结果强调了应变调节的复杂性，扩散变形在碳酸盐基质中产生晶粒尺寸、形状和取向的细微变化。该研究增强了我们对多变形碳酸盐岩变形过程的理解，并通过使用一种新的技术，可以从岩石样本中获得定性和定量信息，为研究地点的地质背景提供了有价值的见解。然而，由于在不同震级和时间尺度上运作的变形过程的多面性，将特定的定向机制与个别构造事件联系起来仍然具有挑战性。

{"title":"From fabric to process: An integrated study of deformed quartz-rich carbonates","authors":"Maria Eleni Taxopoulou , Marine Lartigau , Charles Aubourg , Nicolas E. Beaudoin , Elli-Maria Charalampidou , Jean Paul Callot","doi":"10.1016/j.tecto.2025.231034","DOIUrl":"10.1016/j.tecto.2025.231034","url":null,"abstract":"<div><div>This study investigates the presence and nature of diffuse deformation in a low-porosity carbonate rock that underwent polyphase tectonics and contains a network of veins, tectonic stylolites, and deformation bands. By using a non-destructive methodology based on Electron Backscatter Diffraction, X-ray computed tomography, coupled with results from Anisotropy of Magnetic Susceptibility and the Fry technique, we examine the grain fabric and strain distribution within the rock. Our investigation reveals evidence of quartz reorientation with respect to the polyphase contractional history of the area. Several mechanisms of quartz reorientation were proposed, including rigid reorientation during rotation and diffusion-related processes. The coexistence of ductile and brittle deformation mechanisms in the carbonate matrix indicates a complex response to compaction which can be recorded by the matrix, but does not appear to have a direct effect on the actual amount of shortening, as this is predominantly affected by the deformation bands. Our findings highlight the complexity of strain accommodation, with diffuse deformation creating subtle variations in grain size, shape, and orientation within the carbonate matrix. The study enhances our understanding of deformation processes in poly-deformed carbonate rocks and provides valuable insights into the geological context of the studied locations, by using a novel technique that can be useful for gaining qualitative and quantitative information from the rock samples. However, linking specific reorientation mechanisms to individual tectonic events remains challenging due to the multifaceted nature of deformation processes operating over different magnitudes and timescales.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"923 ","pages":"Article 231034"},"PeriodicalIF":2.6,"publicationDate":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731865","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}

引用次数: 0

Lateral anisotropic gradients in the subslab mantle beneath the Kuril subduction zone detected by observations of quasi-Love wave scattering 准爱波散射观测探测千岛岛俯冲带下地幔横向各向异性梯度

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-26 Epub Date: 2026-01-01 DOI: 10.1016/j.tecto.2025.231066

Wei Cheng , Xiaogang Hu , Yan Lu , Xinghui Liang , Lintao Liu , Panpan Zhang , Yufeng Zhou

The northwestern part of the Pacific plate is subducting into the Kuril trench at high speed, which is expected to result in strong shear on the underlying mantle asthenosphere. However, the splitting measurements in the Kuril subslab mantle reveal complex patterns of seismic anisotropy along the Kuril subduction zone. Love-to-Rayleigh scattered waves (quasi-Love waves) are straightforward indicators of sharp lateral gradients in the anisotropic properties of the Earth's upper mantle (at depths of 100–200 km). Here, we present observations of quasi-Love waves at stations located in Japan from surface waves that sampled the Kuril subslab mantle. Clear quasi-Love waves were diagnosed from 11 earthquakes. The inferred quasi-Love scatterers are located mainly in central and northern Kuril, suggesting the presence of extensive lateral anisotropic gradients in the Kuril subslab mantle, whereas southern Kuril lacks similar anisotropic gradients in the subslab mantle. The lateral anisotropic gradients in northern Kuril may simply reflect the transition from anisotropic subducted slab to mantle flow in the asthenosphere or reflect local toroidal flow around the slab edges, while the lateral anisotropic gradients in northern Kuril may indicate the regions where subslab mantle flow is significantly deflected. Considering the specific slab geometry in and around the Kuril subduction zone, we infer that the detachment of the subducting northwest Pacific slab beneath the Aleutian–Kamchatka junction and the fast slab rollback in central Kuril may be the driving forces for the generation of lateral anisotropic gradients beneath the central Kuril. Our observations of quasi-Love waves provide new constraints on the mantle anisotropy in Kuril.

太平洋板块西北部正高速向千岛海沟俯冲，预计将对下伏地幔软流圈产生强烈剪切。然而，千岛岛板块下地幔的分裂测量揭示了千岛岛俯冲带地震各向异性的复杂模式。Love-to-Rayleigh散射波（准love波）是地球上地幔（深度100-200公里）各向异性特性的急剧横向梯度的直接指示。在这里，我们介绍了日本站对千岛岛板块下地幔表面波的观测结果。从11次地震中诊断出清晰的准love波。推断的准love散射体主要分布在千岛岛中部和北部，表明千岛岛下地幔存在广泛的横向各向异性梯度，而南千岛岛下地幔则缺乏类似的各向异性梯度。南千岛岛北部各向异性梯度可能仅仅反映了软流圈内各向异性俯冲板块向地幔流动的转变或反映了板块边缘附近的局部环面流动，而北千岛岛北部各向异性梯度可能反映了板块下地幔流动明显偏转的区域。考虑到千岛岛俯冲带内及周边特定的板块几何形状，我们推断阿留申-堪察加交界处下俯冲西北太平洋板块的拆离和千岛岛中部板块的快速回滚可能是千岛岛中部下方横向各向异性梯度产生的驱动力。我们的准love波观测为千岛岛地幔各向异性提供了新的约束条件。

{"title":"Lateral anisotropic gradients in the subslab mantle beneath the Kuril subduction zone detected by observations of quasi-Love wave scattering","authors":"Wei Cheng , Xiaogang Hu , Yan Lu , Xinghui Liang , Lintao Liu , Panpan Zhang , Yufeng Zhou","doi":"10.1016/j.tecto.2025.231066","DOIUrl":"10.1016/j.tecto.2025.231066","url":null,"abstract":"<div><div>The northwestern part of the Pacific plate is subducting into the Kuril trench at high speed, which is expected to result in strong shear on the underlying mantle asthenosphere. However, the splitting measurements in the Kuril subslab mantle reveal complex patterns of seismic anisotropy along the Kuril subduction zone. Love-to-Rayleigh scattered waves (quasi-Love waves) are straightforward indicators of sharp lateral gradients in the anisotropic properties of the Earth's upper mantle (at depths of 100–200 km). Here, we present observations of quasi-Love waves at stations located in Japan from surface waves that sampled the Kuril subslab mantle. Clear quasi-Love waves were diagnosed from 11 earthquakes. The inferred quasi-Love scatterers are located mainly in central and northern Kuril, suggesting the presence of extensive lateral anisotropic gradients in the Kuril subslab mantle, whereas southern Kuril lacks similar anisotropic gradients in the subslab mantle. The lateral anisotropic gradients in northern Kuril may simply reflect the transition from anisotropic subducted slab to mantle flow in the asthenosphere or reflect local toroidal flow around the slab edges, while the lateral anisotropic gradients in northern Kuril may indicate the regions where subslab mantle flow is significantly deflected. Considering the specific slab geometry in and around the Kuril subduction zone, we infer that the detachment of the subducting northwest Pacific slab beneath the Aleutian–Kamchatka junction and the fast slab rollback in central Kuril may be the driving forces for the generation of lateral anisotropic gradients beneath the central Kuril. Our observations of quasi-Love waves provide new constraints on the mantle anisotropy in Kuril.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"923 ","pages":"Article 231066"},"PeriodicalIF":2.6,"publicationDate":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894944","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}

引用次数: 0

Active backthrusting in the hanging wall of the Chelungpu Fault: Structural insights from surface deformation analysis 车隆堡断裂上盘活动逆冲：地表变形分析对构造的启示

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-26 Epub Date: 2026-01-14 DOI: 10.1016/j.tecto.2026.231082

Yi-Chun Hsu , Chung-Pai Chang , Jiun-Yee Yen , Chun-Chin Wang , Chih-Heng Lu , Nai-Wun Shih , Shao-Yi Huang , Yu-Ting Kuo , I-Chin Yen

Taiwan lies within an active fold-and-thrust belt along the boundary between the Eurasian Plate and the Philippine Sea Plate, where arc-continent collision drives intense crustal deformation and frequent seismicity. The 1999 Mw 7.6 Chi-Chi earthquake, caused by rupture of the Chelungpu Fault in central Taiwan, brought significant attention to the structural evolution of its hanging wall. To investigate interseismic deformation in this region, we apply Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) to Sentinel-1 imagery from 2018 to 2021. While the main Chelungpu Fault trace remains locked, PSInSAR data reveal localized uplift and eastward motion along the Hsinshe Lineament and Ailiao Fault. Integrating geodetic velocities, topographic features, field observations, and elastic dislocation modeling, we interpret these structures as active backthrusts associated with variations in the Chelungpu ramp geometry. These findings refine previous interpretations of fault-bend folding and demonstrate that stress transfer from the locked frontal thrust may reactivate secondary structures in the hanging wall. This study highlights the role of backthrust faulting in strain accommodation and illustrates the utility of PSInSAR in resolving subtle interseismic processes within complex thrust systems.

台湾位于欧亚板块与菲律宾海板块交界的活跃褶皱冲断带内，弧陆碰撞导致地壳剧烈变形，地震活动频繁。1999年发生在台湾中部的车隆铺断裂带断裂引起的7.6 Mw集集地震，引起了人们对其上盘构造演化的高度关注。为了研究该地区的震间形变，我们将持续散射干涉合成孔径雷达（PSInSAR）应用于2018年至2021年的Sentinel-1图像。在车隆堡主断裂带闭锁的情况下，PSInSAR数据显示了沿新社线和艾寮断裂带的局部隆升和东移。综合大地测量速度、地形特征、野外观测和弹性位错建模，我们将这些结构解释为与车隆堡斜坡几何形状变化相关的活跃逆冲构造。这些发现完善了先前对断层弯曲褶皱的解释，并表明来自封闭的前缘冲断的应力传递可能重新激活上盘的次级构造。这项研究强调了逆冲断层在应变调节中的作用，并说明了PSInSAR在解决复杂逆冲系统中微妙的震间过程中的实用性。

{"title":"Active backthrusting in the hanging wall of the Chelungpu Fault: Structural insights from surface deformation analysis","authors":"Yi-Chun Hsu , Chung-Pai Chang , Jiun-Yee Yen , Chun-Chin Wang , Chih-Heng Lu , Nai-Wun Shih , Shao-Yi Huang , Yu-Ting Kuo , I-Chin Yen","doi":"10.1016/j.tecto.2026.231082","DOIUrl":"10.1016/j.tecto.2026.231082","url":null,"abstract":"<div><div>Taiwan lies within an active fold-and-thrust belt along the boundary between the Eurasian Plate and the Philippine Sea Plate, where arc-continent collision drives intense crustal deformation and frequent seismicity. The 1999 Mw 7.6 Chi-Chi earthquake, caused by rupture of the Chelungpu Fault in central Taiwan, brought significant attention to the structural evolution of its hanging wall. To investigate interseismic deformation in this region, we apply Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) to Sentinel-1 imagery from 2018 to 2021. While the main Chelungpu Fault trace remains locked, PSInSAR data reveal localized uplift and eastward motion along the Hsinshe Lineament and Ailiao Fault. Integrating geodetic velocities, topographic features, field observations, and elastic dislocation modeling, we interpret these structures as active backthrusts associated with variations in the Chelungpu ramp geometry. These findings refine previous interpretations of fault-bend folding and demonstrate that stress transfer from the locked frontal thrust may reactivate secondary structures in the hanging wall. This study highlights the role of backthrust faulting in strain accommodation and illustrates the utility of PSInSAR in resolving subtle interseismic processes within complex thrust systems.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"923 ","pages":"Article 231082"},"PeriodicalIF":2.6,"publicationDate":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995811","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}

引用次数: 0

Controls of temperature on seismic moment released from reactivated faults 重新激活的断层释放的地震力矩的温度控制

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-26 Epub Date: 2026-01-02 DOI: 10.1016/j.tecto.2025.231062

Junpeng Wang , Agathe Eijsink , Matthew Roseboom , Chris Marone , Jacques Riviere , Parisa Shokouhi , Derek Elsworth

Induced seismicity is the main uncertainty to safely produce geothermal energy, raising questions as to how applicable known physical laws are at increased temperatures. We explore the impact of elevated temperatures on maximum seismic moments anticipated in induced seismicity. We conduct laboratory reactivation experiments on a single inclined fracture (SIF) at equilibrated temperatures of 23 °C, 78 °C and 137 °C. Fractures are loaded at a constant shear stress of ∼80 % of the peak shear strength with slip activated by fluid injection. Reactivated seismic moments scale linearly with volume injected but decrease by one-order-of-magnitude with incremented temperatures over the range 23–137 °C. We provide a new perspective of temperature influence on fracture shearing – emphasizing the role of fracture properties (stiffnesses) of elastic tangential and normal stiffnesses on the energetics of slip. We use these stiffnesses to define a relationship linking injected volume to the resulting seismic moment. In transiting from 23 °C to 137 °C, tangential stiffness is halved and normal stiffness quadrupled, thus the resulting seismic moment is potentially reduced by a factor of eight – congruent with observations of reactivated seismic moments over the same temperature range. The change in stiffness can be explained by an increasing contact area, which we also observe by P wave measurements. Our results suggest that increased temperature inhibits fault seismicity and the expected maximum seismic moment of induced seismicity.

诱发地震活动是安全生产地热能的主要不确定因素，这就提出了已知物理定律在温度升高时如何适用的问题。我们探讨了高温对在诱发地震活动中预期的最大地震矩的影响。我们在23°C、78°C和137°C的平衡温度下对单个倾斜裂缝（SIF）进行了实验室再激活实验。裂缝在恒定剪切应力下加载，剪切应力为峰值剪切强度的80%，并由流体注入激活滑移。重新激活的地震矩与注入体积呈线性关系，但在23-137℃范围内，随着温度的增加，地震矩会减小一个数量级。我们提供了温度对断裂剪切影响的新视角-强调弹性切向和法向刚度的断裂特性（刚度）对滑移能量学的作用。我们使用这些刚度来定义注入体积与产生的地震力矩之间的关系。从23°C过渡到137°C时，切向刚度减半，法向刚度翻了两番，因此产生的地震矩可能减少了8倍，这与在相同温度范围内重新激活的地震矩的观测结果一致。刚度的变化可以用接触面积的增加来解释，我们也通过P波测量观察到这一点。研究结果表明，温度升高抑制了断层地震活动性和诱发地震活动性的预期最大地震矩。

{"title":"Controls of temperature on seismic moment released from reactivated faults","authors":"Junpeng Wang , Agathe Eijsink , Matthew Roseboom , Chris Marone , Jacques Riviere , Parisa Shokouhi , Derek Elsworth","doi":"10.1016/j.tecto.2025.231062","DOIUrl":"10.1016/j.tecto.2025.231062","url":null,"abstract":"<div><div>Induced seismicity is the main uncertainty to safely produce geothermal energy, raising questions as to how applicable known physical laws are at increased temperatures. We explore the impact of elevated temperatures on maximum seismic moments anticipated in induced seismicity. We conduct laboratory reactivation experiments on a single inclined fracture (SIF) at equilibrated temperatures of 23 °C, 78 °C and 137 °C. Fractures are loaded at a constant shear stress of ∼80 % of the peak shear strength with slip activated by fluid injection. Reactivated seismic moments scale linearly with volume injected but decrease by one-order-of-magnitude with incremented temperatures over the range 23–137 °C. We provide a new perspective of temperature influence on fracture shearing – emphasizing the role of fracture properties (stiffnesses) of elastic tangential and normal stiffnesses on the energetics of slip. We use these stiffnesses to define a relationship linking injected volume to the resulting seismic moment. In transiting from 23 °C to 137 °C, tangential stiffness is halved and normal stiffness quadrupled, thus the resulting seismic moment is potentially reduced by a factor of eight – congruent with observations of reactivated seismic moments over the same temperature range. The change in stiffness can be explained by an increasing contact area, which we also observe by P wave measurements. Our results suggest that increased temperature inhibits fault seismicity and the expected maximum seismic moment of induced seismicity.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"923 ","pages":"Article 231062"},"PeriodicalIF":2.6,"publicationDate":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894840","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}

引用次数: 0

Multi-mode pre-seismic geomagnetic anomalies reveal potential mechanisms of the August 15, 2007, Mw8.0 Pisco earthquake: Pressure-stimulated rock current 多模态震前地磁异常揭示了2007年8月15日Mw8.0皮斯科地震的潜在机制：压力刺激的岩石流

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-16 Epub Date: 2026-01-02 DOI: 10.1016/j.tecto.2025.231065

Busheng Xie , Lixin Wu , Licheng Sun , Youyou Xu , Akimasa Yoshikawa , Wenfei Mao

This study investigates multi-type pre-seismic geomagnetic anomalies observed before the August 15, 2007, M_w 8.0 Pisco earthquake, and proposes Pressure-Stimulated Rock Current (PSRC) as an underlying mechanism. Using time-domain and frequency-domain analyses, the research identifies ultra-low frequency (ULF) emissions and magnetic vector deflections related to the earthquake. Based on the diurnal variation anomalies across multiple stations, a novel algorithm, the Forward Intersection of Magnetic Disturbance Vector (FIMDV), was developed to estimate the location of the seismogenic zone by analyzing the magnetic vector deflection. The FIMDV algorithm integrates the magnitude and directional information of magnetic disturbance vectors to pinpoint rock currents, providing new insights into geomagnetic anomalies and earthquake preparation. The study identifies two key phases of potential PSRC generation: the crack coalescence phase, associated with ULF emissions detected a month before the earthquake, and the crack interconnection phase, which corresponds to diurnal anomalies observed on the earthquake day. The former involves microcrack formation and positive hole activation, leading to varying electromagnetic fields that propagate as low-frequency waves detectable at the ground surface. The latter involves cracks interconnection facilitating the propagation of direct rock currents to the ground surface and inducing stable magnetic disturbance vectors. Geological validation confirmed that the local lithology, rich in silicate minerals, enables positive holes activation and propagation, further supporting PSRC as a driving mechanism of the observed multi-mode geomagnetic anomalies, including diurnal variation, vector deflection, Z/H polarization ratio, and horizontal polarization ellipse.

本文对2007年8月15日mw8.0 Pisco地震前观测到的多类型震前地磁异常进行了研究，并提出压力刺激岩石电流（PSRC）是其潜在机制。通过时域和频域分析，该研究确定了与地震有关的超低频（ULF）发射和磁矢量偏转。基于多台站的日变化异常，提出了一种新的算法——磁扰动矢量正向交会（FIMDV），通过分析磁矢量偏转来估计孕震带的位置。FIMDV算法集成了磁扰动矢量的震级和方向信息来精确定位岩石电流，为地磁异常和地震准备提供了新的见解。该研究确定了潜在PSRC产生的两个关键阶段：裂缝合并阶段，与地震前一个月检测到的超低辐射辐射有关；裂缝互连阶段，与地震当天观测到的日异常相对应。前者涉及微裂纹的形成和正孔激活，导致不同的电磁场以低频波的形式传播，在地表可探测到。后者涉及裂缝互连，有利于直接岩石电流向地表传播，并产生稳定的磁扰动矢量。地质验证证实，局部岩性富含硅酸盐矿物，有利于孔洞的激活和扩展，进一步支持PSRC是观测到的多模地磁异常（包括日变化、矢量偏转、Z/H极化比和水平极化椭圆）的驱动机制。

{"title":"Multi-mode pre-seismic geomagnetic anomalies reveal potential mechanisms of the August 15, 2007, Mw8.0 Pisco earthquake: Pressure-stimulated rock current","authors":"Busheng Xie , Lixin Wu , Licheng Sun , Youyou Xu , Akimasa Yoshikawa , Wenfei Mao","doi":"10.1016/j.tecto.2025.231065","DOIUrl":"10.1016/j.tecto.2025.231065","url":null,"abstract":"<div><div>This study investigates multi-type pre-seismic geomagnetic anomalies observed before the August 15, 2007, M<sub>w</sub> 8.0 Pisco earthquake, and proposes Pressure-Stimulated Rock Current (PSRC) as an underlying mechanism. Using time-domain and frequency-domain analyses, the research identifies ultra-low frequency (ULF) emissions and magnetic vector deflections related to the earthquake. Based on the diurnal variation anomalies across multiple stations, a novel algorithm, the Forward Intersection of Magnetic Disturbance Vector (FIMDV), was developed to estimate the location of the seismogenic zone by analyzing the magnetic vector deflection. The FIMDV algorithm integrates the magnitude and directional information of magnetic disturbance vectors to pinpoint rock currents, providing new insights into geomagnetic anomalies and earthquake preparation. The study identifies two key phases of potential PSRC generation: the crack coalescence phase, associated with ULF emissions detected a month before the earthquake, and the crack interconnection phase, which corresponds to diurnal anomalies observed on the earthquake day. The former involves microcrack formation and positive hole activation, leading to varying electromagnetic fields that propagate as low-frequency waves detectable at the ground surface. The latter involves cracks interconnection facilitating the propagation of direct rock currents to the ground surface and inducing stable magnetic disturbance vectors. Geological validation confirmed that the local lithology, rich in silicate minerals, enables positive holes activation and propagation, further supporting PSRC as a driving mechanism of the observed multi-mode geomagnetic anomalies, including diurnal variation, vector deflection, Z/H polarization ratio, and horizontal polarization ellipse.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231065"},"PeriodicalIF":2.6,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894841","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}

引用次数: 0

Detailed structure of upper mantle discontinuities beneath the Pamir-Hindu Kush from the short period regional seismic array 来自短周期区域地震阵的帕米尔-兴都库什上地幔不连续体的详细结构

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-16 Epub Date: 2025-12-31 DOI: 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.

2023年8月，帕米尔高原-兴都库什山脉发生两次矩级分别为5.8级和5.3级的中深度地震。我们从一个临时的区域短周期阵列中选择了三个表现出二维三角形阵列响应函数的子阵列。对于每个事件/子阵列对，数据相对于初始p阶段进行倾斜堆叠和规范化。P410p和s140p两个次级到达带出了帕米尔-兴都库什地区上地幔的信息。从410 km不连续的p波反射深度表明，兴都库什山脉的俯冲冷板块穿过了不连续，当反射点接近冷核时，将其抬升到较浅的深度。反射深度沿帕米尔板块走向的加深趋势与俯冲帕米尔板块西部在350 km以下与兴都库什板块毗邻的分裂模式相一致。我们的数据提供了相邻的帕米尔-兴都库什板块与正常地幔物质之间的边界带的直接采样。我们观测到一个P波，s140p，是由一个上升的S波在140千米的深度转换而来的。这个s140p相在一个空间受限的西北-东南方向区域内表现出能量的快速下降，表明存在一个接近垂直的速度边界。

{"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":"2026-02-16","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}

引用次数: 0

Timing of India-Asia diachronous collision: A view from the westernmost Indian margin, Pakistan 印度-亚洲历时碰撞的时机：从印度最西端边缘，巴基斯坦的视角

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-16 Epub Date: 2026-01-03 DOI: 10.1016/j.tecto.2025.231067

Muhammad Qasim , Owais Tayyab , Lin Ding , Javed Iqbal Tanoli , Muhammad Awais , Kamran Tabassum , Fulong Cai , Zhang Dingding , Ishtiaq A.K. Jadoon

The India-Asia collision along the western Indian Plate margin remains debated, with contrasting models for the first arrival of Asian-derived detritus in the region. The Sulaiman Fold–Thrust Belt (SFB) in southwestern Pakistan preserves a crucial record of this transition, with the Paleocene to Eocene stratigraphic succession providing insights into sediment provenance shifts. To constrain the collision timing, we analyzed detrital zircon for U-Pb-Hf geochronology, supplemented by petrography and zircon Th/U geochemistry, from Cenozoic sequences exposed in the Mughalkot section, SFB. Detrital zircon age distributions from the Paleocene Dunghan Formation are dominated by ∼500–1100 Ma, ∼1400–2000 Ma, and ∼ 2400–2600 Ma grains, indicating a primary sediment source from the Indian Plate. A similar detrital zircon age pattern in the early to middle Eocene Ghazij Formation suggests continued derivation from the Indian craton. However, a pronounced provenance shift is observed in the lowermost Baska Formation (middle Eocene), marked by the arrival of Late Cretaceous–Paleocene (<100 Ma) detrital zircons, which possess Th/U ratios (>0.3) indicative of an igneous origin. Juvenile Hf signatures of the younger detrital zircons further support their derivation from the Kohistan-Ladakh Arc, which is located between the Indian and the Asian plates in North Pakistan. The arrival of this detritus signals the onset of the India-Asia collision, constrained by the maximum depositional age to post–51 Ma. When compared to northern and central segments of the Himalayan orogen, this suggests a diachronous collision with its later onset in the westernmost region. These findings contribute to the broader framework of India-Asia convergence, supporting models that invoke regional variability in collision timing and foreland basin evolution.

沿着西印度板块边缘的印度-亚洲碰撞仍然存在争议，对于亚洲来源的碎屑首次到达该地区，存在不同的模型。巴基斯坦西南部的苏莱曼褶皱冲断带（SFB）保存了这一转变的重要记录，古新世到始新世的地层演替为沉积物物源转移提供了见解。为了约束碰撞时间，我们分析了SFB Mughalkot剖面新生代序列的碎屑锆石U- pb - hf年代学，并补充了岩石学和锆石Th/U地球化学。古新世Dunghan组碎屑锆石年龄分布以~ 500 ~ 1100 Ma、~ 1400 ~ 2000 Ma和~ 2400 ~ 2600 Ma颗粒为主，表明其主要沉积源来自印度板块。始新世早至中Ghazij组的碎屑锆石年龄模式相似，表明其继续源自印度克拉通。然而，在巴斯卡组最下部（中始新世），物源转移明显，标志着晚白垩世-古新世（<100 Ma）碎屑锆石的到来，其Th/U比（>0.3）表明其成因为火成岩。这些碎屑的到来标志着印度-亚洲碰撞的开始，受最大沉积年龄限制在51 Ma之后。与喜马拉雅造山带的北部和中部部分相比，这表明在最西部地区发生的碰撞较晚，是一次历时性碰撞。这些发现有助于建立更广泛的印度-亚洲辐合框架，支持碰撞时间和前陆盆地演化的区域变异性模型。

{"title":"Timing of India-Asia diachronous collision: A view from the westernmost Indian margin, Pakistan","authors":"Muhammad Qasim , Owais Tayyab , Lin Ding , Javed Iqbal Tanoli , Muhammad Awais , Kamran Tabassum , Fulong Cai , Zhang Dingding , Ishtiaq A.K. Jadoon","doi":"10.1016/j.tecto.2025.231067","DOIUrl":"10.1016/j.tecto.2025.231067","url":null,"abstract":"<div><div>The India-Asia collision along the western Indian Plate margin remains debated, with contrasting models for the first arrival of Asian-derived detritus in the region. The Sulaiman Fold–Thrust Belt (SFB) in southwestern Pakistan preserves a crucial record of this transition, with the Paleocene to Eocene stratigraphic succession providing insights into sediment provenance shifts. To constrain the collision timing, we analyzed detrital zircon for U-Pb-Hf geochronology, supplemented by petrography and zircon Th/U geochemistry, from Cenozoic sequences exposed in the Mughalkot section, SFB. Detrital zircon age distributions from the Paleocene Dunghan Formation are dominated by ∼500–1100 Ma, ∼1400–2000 Ma, and ∼ 2400–2600 Ma grains, indicating a primary sediment source from the Indian Plate. A similar detrital zircon age pattern in the early to middle Eocene Ghazij Formation suggests continued derivation from the Indian craton. However, a pronounced provenance shift is observed in the lowermost Baska Formation (middle Eocene), marked by the arrival of Late Cretaceous–Paleocene (<100 Ma) detrital zircons, which possess Th/U ratios (>0.3) indicative of an igneous origin. Juvenile Hf signatures of the younger detrital zircons further support their derivation from the Kohistan-Ladakh Arc, which is located between the Indian and the Asian plates in North Pakistan. The arrival of this detritus signals the onset of the India-Asia collision, constrained by the maximum depositional age to post–51 Ma. When compared to northern and central segments of the Himalayan orogen, this suggests a diachronous collision with its later onset in the westernmost region. These findings contribute to the broader framework of India-Asia convergence, supporting models that invoke regional variability in collision timing and foreland basin evolution.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231067"},"PeriodicalIF":2.6,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894830","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}

引用次数: 0

Updated map and insights into emplacement conditions of Ighrem doleritic dyke (Anti-Atlas Mountains, Morocco) 摩洛哥反阿特拉斯山脉（Anti-Atlas Mountains, Morocco） Ighrem白云岩岩脉的更新地图及就位条件研究

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-16 Epub Date: 2025-12-26 DOI: 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.

在反阿特拉斯山脉中发现了两条北东向的长白云岩岩脉。富姆兹圭德岩脉是中大西洋岩浆省保存最完好的产物之一，引起了地质研究的广泛兴趣。然而，由于缺乏未改变的岩石暴露，对Ighrem堤防的探索相对较少。在这篇论文中，我们通过分析和解释新的高分辨率航磁数据来研究Igherm岩脉，以跟踪其在缺乏地表暴露的大面积上的轨迹和延伸。地质解释结果突出了Igherm堤防的地球物理特征，使我们能够提出更新的堤防图。这张地图显示了堤坝向东北和西南延伸了270多公里。此外，Igherm岩脉似乎被破碎成多个具有不同形态的分段，其中大多数没有到达表面，并且在相邻分段之间的继电器的许多位置显示出许多不同的分段结构。根据反阿特拉斯地区的岩浆和构造环境，我们认为Ighrem岩脉的侵位主要是由构造控制的。然而，我们认为区域构造模式、局部和区域应力场的变化、岩浆流动条件和寄主岩石的非均质性等其他因素可能对岩脉的侵入是否到达地表或在不同的地壳水平上被阻止起作用，但也控制着岩脉的几何形状。

{"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":"2026-02-16","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}

引用次数: 0

Multi-source geodetic constraints on 3D crustal deformation, strain accumulation, and fault locking in the Tianshan Orogen 天山造山带三维地壳变形、应变聚集和断层锁闭的多源大地测量约束

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-16 Epub Date: 2026-01-01 DOI: 10.1016/j.tecto.2025.231063

Jiangtao Qiu , Jianbao Sun , Lingyun Ji , Liangyu Zhu

The Tianshan orogen, located at the northern margin of the India–Eurasia collision zone, is one of the world's most seismically active intracontinental mountain belts. However, a comprehensive understanding of its crustal deformation, strain accumulation, and fault locking patterns remains limited due to the lack of large-scale, high-resolution geodetic observations. In this study, we integrate Sentinel-1 interferometric synthetic aperture radar (InSAR) time-series analysis with regional Global Navigation Satellite System (GNSS) data to reconstruct a three-dimensional (3D) deformation field covering the entire Tianshan range. We apply atmospheric corrections using ERA5 reanalysis and constrain the InSAR solutions with GNSS data to significantly improve their consistency, enabling reliable quantification of crustal motions. Our results reveal pronounced spatial variability in north–south shortening, with rates reaching ∼20 mm/yr in the western segment (75°-79°E) and decreasing to 6–9 mm/yr in the eastern segment (85°-87°E). Uplift rates are higher in the South Tianshan (1.8–2.2 mm/yr) than in the North Tianshan (0.8–1.2 mm/yr), while strike-slip motions are concentrated along the southern foreland. Non-tectonic deformation is also identified, including large-scale subsidence due to groundwater extraction (∼34 mm/yr) and localized oilfield-induced subsidence (∼20 mm/yr). From the 3D deformation field, we derive the strain rate distribution and invert fault locking parameters using a block model with Bayesian optimization. High strain accumulation and strong locking are observed along the Pamir frontal thrust, the Maidan fault (which ruptured in the 2024 Mw 7.1 Wushi earthquake), the south Issyk-Kul fault, the Kepingtag fault (which ruptured in the 2020 Mw 6.0 Jiashi earthquake), and the Qiulitag belt. Our findings highlight the coupled tectonic and anthropogenic processes shaping Tianshan deformation and identify the western Qiulitag as a potential source for future large earthquakes.

天山造山带位于印度-欧亚碰撞带的北缘，是世界上地震最活跃的大陆内山带之一。然而，由于缺乏大规模、高分辨率的大地测量观测，对其地壳变形、应变积累和断层锁定模式的全面了解仍然有限。在这项研究中，我们将Sentinel-1干涉合成孔径雷达（InSAR）时间序列分析与区域全球导航卫星系统（GNSS）数据相结合，重建了覆盖整个天山山脉的三维（3D）变形场。我们使用ERA5再分析进行大气校正，并将InSAR解决方案与GNSS数据进行约束，以显着提高其一致性，从而实现可靠的地壳运动量化。我们的研究结果表明，南北缩短的空间变异性明显，西段（75°-79°E）的速率为~ 20 mm/yr，而东段（85°-87°E）的速率为6-9 mm/yr。南天山隆升速率（1.8 ~ 2.2 mm/yr）高于北天山隆升速率（0.8 ~ 1.2 mm/yr），走滑运动沿南前陆集中。此外，还发现了非构造变形，包括地下水开采引起的大规模沉降（~ 34 mm/yr）和局部油田引起的沉降（~ 20 mm/yr）。从三维变形场出发，利用贝叶斯优化的块体模型推导出应变率分布，反演出断层锁定参数。沿帕米尔前缘逆冲、麦丹断裂（2024 Mw 7.1吴市地震破裂）、南伊塞克-库尔断裂、柯平塔格断裂（2020 Mw 6.0贾市地震破裂）和秋里塔格带观察到高应变积累和强锁断。我们的研究结果强调了构造和人为作用的耦合作用对天山变形的影响，并确定了秋里塔格西部是未来大地震的潜在震源。

{"title":"Multi-source geodetic constraints on 3D crustal deformation, strain accumulation, and fault locking in the Tianshan Orogen","authors":"Jiangtao Qiu , Jianbao Sun , Lingyun Ji , Liangyu Zhu","doi":"10.1016/j.tecto.2025.231063","DOIUrl":"10.1016/j.tecto.2025.231063","url":null,"abstract":"<div><div>The Tianshan orogen, located at the northern margin of the India–Eurasia collision zone, is one of the world's most seismically active intracontinental mountain belts. However, a comprehensive understanding of its crustal deformation, strain accumulation, and fault locking patterns remains limited due to the lack of large-scale, high-resolution geodetic observations. In this study, we integrate Sentinel-1 interferometric synthetic aperture radar (InSAR) time-series analysis with regional Global Navigation Satellite System (GNSS) data to reconstruct a three-dimensional (3D) deformation field covering the entire Tianshan range. We apply atmospheric corrections using ERA5 reanalysis and constrain the InSAR solutions with GNSS data to significantly improve their consistency, enabling reliable quantification of crustal motions. Our results reveal pronounced spatial variability in north–south shortening, with rates reaching ∼20 mm/yr in the western segment (75°-79°E) and decreasing to 6–9 mm/yr in the eastern segment (85°-87°E). Uplift rates are higher in the South Tianshan (1.8–2.2 mm/yr) than in the North Tianshan (0.8–1.2 mm/yr), while strike-slip motions are concentrated along the southern foreland. Non-tectonic deformation is also identified, including large-scale subsidence due to groundwater extraction (∼34 mm/yr) and localized oilfield-induced subsidence (∼20 mm/yr). From the 3D deformation field, we derive the strain rate distribution and invert fault locking parameters using a block model with Bayesian optimization. High strain accumulation and strong locking are observed along the Pamir frontal thrust, the Maidan fault (which ruptured in the 2024 Mw 7.1 Wushi earthquake), the south Issyk-Kul fault, the Kepingtag fault (which ruptured in the 2020 Mw 6.0 Jiashi earthquake), and the Qiulitag belt. Our findings highlight the coupled tectonic and anthropogenic processes shaping Tianshan deformation and identify the western Qiulitag as a potential source for future large earthquakes.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"922 ","pages":"Article 231063"},"PeriodicalIF":2.6,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894842","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}

引用次数: 0

Crustal anisotropy and deformation in the Zagros collision belt 扎格罗斯碰撞带地壳各向异性与变形

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-02-16 Epub Date: 2025-12-30 DOI: 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-

κ

-c stacking method was employed to estimate the Moho depth,

\frac{V_{P}}{V_{S}}

ratio (

κ

), 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.

伊朗高原是由阿拉伯板块和欧亚板块持续碰撞形成的，在阿尔卑斯-喜马拉雅带中占据着地球动力学上重要的位置。研究它的变形揭示了它在这个构造框架中独特而复杂的作用。新特提斯洋在这一辐合过程中的俯冲作用推动了扎格罗斯地区的分布缩短，形成了变质带、岩浆弧、破碎隆起区、沉积盆地和褶皱带等多种地质特征。本研究旨在提高我们对扎格罗斯地区地壳各向异性和地壳厚度的认识。通过对区域台站地震记录的处理，我们采用两阶段方法对上、下地壳变形进行了表征。首先，采用广义H-κ-c叠加法估算莫霍深度、VPVS比（κ）、地壳各向异性和莫霍倾角；在Sanandaj-Sirjan变质带（SSZ）北部确定了最厚的地壳剖面。然后，在考虑上覆层影响的情况下，利用曲线拟合技术对转换Ps相进行逐层各向异性分析。这揭示了大多数地震台站上、下地壳具有明显的各向异性特征。将这些变形模式与先前的研究进行比较，可以增强我们对浅层和深层地壳断层的理解。主要发现包括上地壳存在SPO（形状优先取向），下地壳存在LPO（格位优先取向），缺乏垂直相干的整体地壳各向异性，扎格罗斯北部可能存在板块断裂，扎格罗斯中部和南部存在逆冲作用。这些结果为扎格罗斯地区复杂的构造演化提供了新的见解。

{"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":"2026-02-16","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}

引用次数: 0