Tectonophysics最新文献_第4页

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 : 2026-01-03 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。

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引用次数: 0

Mesozoic differential uplift-exhumation processes in the western Tian Shan, Uzbekistan: Constraints from apatite/zircon fission track and (UTh)/He thermochronology 乌兹别克斯坦西天山中生代差异性隆升-掘出过程：磷灰石/锆石裂变径迹和(U - Th)/He热年代学的约束

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2026-01-03 DOI: 10.1016/j.tecto.2026.231068

Weini Zhang , Wengao Zhang , Fengbin Han , Jian Chang , Hailong Huo , Jiayong Pan , Bakhtiar Nurtaev , Shukhrat Shukurov , Zhengle Cheng

The western Tian Shan in Uzbekistan, forming the orogen's western terminus, provides critical insights into Meso-Cenozoic tectonic evolution through its uplift-exhumation history. This study integrates apatite/zircon fission-track (AFT/ZFT) and zircon (UTh)/He analyses on 15 granitic samples from the Kyzylkum Nurata segment. Key findings include: (1) AFT ages span 67.50 ± 10.03–215.31 ± 14.53 Ma, with short mean track lengths (11.47 ± 1.38–12.65 ± 0.75 μm), indicating partial thermal resetting.(2)The western Tian Shan experienced Meso-Cenozoic multi-phase rapid uplift-exhumation, revealing a progressive northwest-to-southeast younging of apatite fission track ages and a marked contrast in exhumation regimes between the northwestern Nurata Range and adjacent ranges within the Kyzylkum-Nurata segment, highlighting spatiotemporal migration of tectonic activity and localized deformation partitioning. (3) Three thermo-tectonic phases were identified: Triassic rapid exhumation responding to Turan-Qiangtang/Paleo-Asia collision; Jurassic-Early Cretaceous uplift controlled by Lhasa-Qiangtang collision effects; Late Cretaceous-Cenozoic burial-rejuvenation cycles linked to Kohistan-Dras arc accretion in the Late Cretaceous and India-Eurasia/Kunlun-Pamir collisions in the Cenozoic. Differential exhumation patterns reflect inherited crustal heterogeneity, suture zone reactivation, and far-field stresses from Tethyan plate interactions. This study fills critical gaps in understanding Meso-Cenozoic uplift-exhumation processes in the westernmost Tian Shan, providing enhanced constraining models for the tectonic evolution of the entire orogen. Based on the investigation into the dynamic origins of uplift and exhumation, it can be concluded that the trend of uplift and exhumation in the Kyzylkum-Nurata segment of the Western Tian Shan propagated from southeast to northwest.

乌兹别克斯坦西天山形成了造山带的西端，通过其隆升-掘出历史，为中新生代构造演化提供了重要的认识。本文对Kyzylkum Nurata段15个花岗岩样品进行了磷灰石/锆石裂变径迹（AFT/ZFT）和锆石（UTh /He）分析。主要发现包括：(1)AFT年龄跨度为67.50±10.03 ~ 215.31±14.53 Ma，平均径迹长度较短（11.47±1.38 ~ 12.65±0.75 μm），表明部分热复位；(2)天山西部经历中新生代多期快速隆升掘出，磷灰石裂变径迹年龄由西北向东南渐进性年轻化，努拉塔山脉西北部与kyzylkm -Nurata段相邻山脉的掘出制度对比明显，突出了构造活动的时空迁移和局部变形分区。(3)确定了三个热构造阶段：三叠纪快速掘出响应吐兰-羌塘/古亚洲碰撞；拉萨-羌塘碰撞作用控制侏罗纪-早白垩世隆升；晚白垩世-新生代埋藏-恢复旋回与晚白垩世Kohistan-Dras弧增生和新生代印度-欧亚/昆仑-帕米尔碰撞有关。不同的挖掘模式反映了继承的地壳非均质性、缝合带的重新激活和特提斯板块相互作用的远场应力。该研究填补了认识天山最西端中新生代隆升-掘出过程的关键空白，为整个造山带的构造演化提供了强化的约束模式。通过对隆升和掘出动力成因的研究，认为西天山克孜库姆—努拉塔段隆升和掘出趋势是由东南向西北扩展的。

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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 : 2026-01-02 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。

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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 : 2026-01-02 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。

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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 : 2026-01-01 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。

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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 : 2026-01-01 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。

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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 : 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。

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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 : 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。

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引用次数: 0

Frictional strength and stability of laterally heterogeneous faults under fluid diffusion conditions 流体扩散条件下横向非均质断层的摩擦强度与稳定性

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-12-29 DOI: 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.

岩石非均质性和流体在天然断裂带中普遍存在。它们是如何相互作用影响断层强度和摩擦稳定性的，仍然没有得到充分的了解，特别是考虑到流体扩散。在这里，我们建立了一个基于速率和状态摩擦（RSF）的二自由度弹簧滑块模型来研究非均质断层（包括富含石英和粘土的断层）的摩擦行为。我们的模型结合了两个断层泥段之间的横向流体扩散和孔隙压力相互作用。研究结果表明，在富含石英的断层中，粘土含量的增加导致断层强度逐渐减弱，摩擦稳定性增强。在石英为主的断层中，高水力扩散性显著地延缓了粘滑不稳定性的发生。我们的研究结果复制了从稳定蠕变、慢滑到动态破裂的各种滑动行为，并控制了断层组成、摩擦参数比和流体扩散特性。我们证明孔隙压力扰动，特别是流体扩散条件下斑块间压力差，可以驱动滑移行为的转变。我们的发现为理解富含流体的非均质俯冲带断层带的地震和地震滑动行为提供了一个物理框架。

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引用次数: 0

Finite element modelling of evaporite flow constrained by kinematic markers in the Messinian of the Eastern Mediterranean 东地中海墨西尼亚地区受运动标记约束的蒸发岩流有限元模拟

IF 2.6 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-12-26 DOI: 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.

盐在地质时间尺度上具有独特的流动能力，即使是在低差应力下也能流动。这促进了全球许多沉积盆地复杂构造的形成。由于许多盐盆地在沉积后经历了多个变形阶段，因此解开变形的关键驱动因素往往具有挑战性。在这里，我们使用盆地尺度的数值模拟，重点关注盐的地质蠕变，以重建作为东地中海运动标记的位移流体逸出管道。我们使用参数扫描来证明最大水平管道位移的数值解包含在盆地倾斜和蒸发体流变的实际值中。最优的模拟流型是抛物线型，低粘度模型倾向于s型解，高粘度模型倾向于层流线性解。模型导出的流动剖面与理想的Couette流之间存在显著差异，这可能会给先前的整体流动重建带来挑战。这些结果是独特的观测约束，并提供了盆地尺度盐流背后的驱动力，以及盆地的应力演化和蒸发岩序列中被动应变标志的性质。

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引用次数: 0