Tectonophysics最新文献

Complex seismogenic fault system for the 2022 Ms6.0 Maerkang (China) earthquake sequence resolved with reliable seismic source parameters

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-28 DOI: 10.1016/j.tecto.2025.230718

Lihua Mo , Minhan Sheng , Risheng Chu , Jun Xie , Sidao Ni

The Bayan Har block in central Tibetan Plateau is characterized by low historical seismicity and has rarely experienced M6+ earthquakes. However, on June 10, 2022, at 01:28 AM (UTC + 8), an

M_{s}

6.0 earthquake struck Maerkang in Sichuan Province, China, within the Bayan Har block. Four foreshocks and eight aftershocks with magnitudes greater than 3 occurred during the week of the mainshock with the largest foreshock reaching

M_{s}

5.8. Previous studies have suggested two probable seismogenic faults. One proposes that the earthquake sequence occurred on the V-shaped Songgang secondary fault, while the other suggests an unmapped fault located east of the V-shaped fault is the causative fault. Additionally, there are inconsistencies in the focal depth and rupture direction in these studies. To better identify the seismogenic faults of the Maerkang earthquakes, we first estimated the focal mechanisms and centroid depths of all M

\geq

2.9 events during one week of the mainshock occurence, using both regional and teleseismic waveform data. We then refined the mainshock epicenter by by incorporating 3D velocity models to account for their influence on the earthquake location. Other events were relocated relative to the mainshock using the surface wave differential times. Finally, we analyzed the rupture directivity of the mainshock and the

M_{s}

5.8 foreshock via the empirical Green's function (EGF) method. The results suggest that the mainshock likely ruptured along an unmapped fault to the east of the V-shaped Songgang secondary fault, while the

M_{s}

5.8 foreshock occurred on the Songgang fault itself, suggesting complex fault system for the earthquake sequence.

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引用次数: 0

Delineation of crustal structure and composition in the Northwest Himalaya and adjoining Indo-Gangetic Plain

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-25 DOI: 10.1016/j.tecto.2025.230717

Amlanjyoti Das , Devajit Hazarika , Pritom Neog , Naresh Kumar , Dilip Kumar Yadav

We utilize the H-k stacking technique on P-wave receiver functions from 38 seismic stations to estimate the crustal thickness and Vp/Vs ratio in the NW Himalaya and the adjoining Indo-Gangetic Plain (IGP). We observe varying crustal thickness from ∼29 km in the IGP to ∼50–60 km in the Higher Himalayan Crystalline Zone. An abrupt crustal thickening of ∼47–54 km observed near Jwalamukhi Thrust is due to significant crustal shortening along the fault. Inferred higher Vp/Vs values of 1.78–1.84 in the IGP may result from the underplating of mafic materials in the Precambrian. The presence of thick sediments towards the Himalayan Frontal Thrust, further, contributes to the extremely high Vp/Vs of 1.89–2.02. The intermediate Vp/Vs of ∼1.74 in the Sub Himalayan Zone indicates the reworking of the mafic crust by delamination of the lower crust or the greater influence of the overlying Himalayan wedge, comprised of felsic to intermediate rock composition. Higher Vp/Vs values in the Kishtwar (1.81–1.93) and Kashmir Valley (1.80–1.93) are possibly due to the presence of volcanic rocks and the effect of the mid-crustal low-velocity layer. Integration of our results with previous studies reveals a heterogenous crustal structure characterized by both arc-normal and arc-parallel variations which may have resulted from varying convergence rates and the influence of subsurface extension of active transverse ridges beneath the Himalaya. The varying Vp/Vs values may result from diverse crustal rock compositions and partial melt/fluid zones. These partial melts alter the mechanical properties of rocks leading to brittle failure and thus promoting seismicity.

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引用次数: 0

Seismic evidence of subduction during assembly of the North China Craton from multimodal dispersion inversion

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-22 DOI: 10.1016/j.tecto.2025.230715

Yanyan Zhang , Xiaofei Chen , Juqing Chen , Gongheng Zhang , Zhengbo Li , Lei Pan , Jiannan Wang , Zhifeng Ding , Xingchen Wang , Songyong Yuan

The Precambrain basement of the North China Craton (NCC) was formed through the merger of micro-continental blocks, the amalgamation mode of which has remained debated. To provide further insights and better understand the underground structures, we construct a more detailed shear wave velocity model of crust and uppermost mantle in the central and western NCC using multimodal ambient noise tomography. The multimodal Rayleigh wave dispersion curves are obtained through the Frequency-Bessel transform, utilizing seismic records from 548 stations in the ChinArray-Himalaya project. Subsequently, we employ the quasi-Newton method to invert the shear wave velocity model to a depth of 60 km. The results reveal a southward low-velocity subduction-like feature in the upper-middle crust south of the Solonker Suture Zone to the Inner Mongolia Suture Zone. This feature likely represents the subduction remnants associated with the southward subducted Paleo-Asian Ocean slab. Additionally, the model highlights a westward intra-crustal low-velocity downthrust body beneath the Trans-North China Orogen, potentially indicating relics of subduction from the Paleoproterozoic amalgamation of the NCC. Moreover, we observe a widely distributed low-velocity layer within the lower crust of the Ordos Block, which may indicate a felsic-dominated lower crust, likely formed during the prolonged tectonic stability following the ancient subduction-collision processes of the NCC.

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引用次数: 0

Analysis of seismic reflection data from the Northern Hispaniola margin: Implications for the recent evolution of the Northern Caribbean Plate boundary

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-20 DOI: 10.1016/j.tecto.2025.230714

A. Oliveira de Sá , S. Leroy , E. d'Acremont , S. Lafuerza , J.L. Granja-Bruña , R. Momplaisir , D. Boisson , L. Watremez , B. Moreno , J. Corbeau

The northern margin of Hispaniola features an accretionary prism with morphological structures shaped by tectonic, hydrodynamic and sedimentary processes in oblique convergence between North American and Caribbean plates. The HAITISIS data in the northern Caribbean plate boundary elucidate the relationships between fault-driven tectonic activity, seafloor morphology, and effects of transpressional deformation. We evidence an E-W-trending spatial variation in deformation accommodation and sedimentary records along the accretionary prism. The distinct morpho-structural character of the seafloor and sedimentation patterns originated during the Upper Miocene-Pliocene tectonic reorganization of the northern Caribbean Plate boundary, which is associated with the onset of the oblique collision of the Caribbean and North American Plates carrying Hispaniola to the transpressive plate boundary opposite the Bahamas Carbonate Platform. An accretionary prism is formed, and segments of the eastern strand of the Septentrional-Oriente Fault Zone (SOFZ) are activated, resulting in lateral sediment source displacements, influencing sedimentary infill and deformation patterns.

A mass transport deposit (MTD) in the Eastern domain caused differential compaction and remobilization of recent seismic units and has affected the seafloor morphology. The MTD is absent in the Western domain, and canyons are found in the Eastern domain.

The early Miocene SOFZ onset and evolution is not a continuous eastward propagation. Lateral displacements of canyons provide a chronology for strike-slip and thrust faults before the SOFZ initiation and the formation of the current fault segments. The variations in fault density, cumulative displacement along strike-slip faults, morphology of Northern Hispaniola insular slope (including width and tectonic style), and tilting of basin surfaces suggest the underthrusting of the North American plate beneath the Caribbean plate has ceased at the transition between the Eastern and Western domains. This may be attributed to westward rheological transition of North American plate's crust (from oceanic to continental) at the level of the Bahamas platform.

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引用次数: 0

The Lyngen Magmatic Complex ophiolite: preservation of pre- and syn-collisional structures and implications for the nappe thrusting sequence in the Northern Norwegian Caledonides

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-14 DOI: 10.1016/j.tecto.2025.230706

Marina Galindos-Alfarache , Holger Stünitz , Mathieu Soret , Guillaume Bonnet , Benoît Dubacq , Morgan Ganerød

The Lyngen Magmatic Complex (Northern Norway) marks a major discontinuity in the metamorphic gradient of the North Norwegian Caledonides nappe sequence. The Lyngen Magmatic Complex preserves pre- and syn-collisional structures and parageneses of the Caledonian orogeny. This study differentiates the two deformation events and offers a tectono-metamorphic model for the region, using a combination of field-based data, geochemical analysis, radiochronometric dating, and thermodynamic modelling. It is demonstrated that the precollisional event (D1) developed in a dextral strike-slip transpressional regime, generating NS-trending subvertical shear zones with subhorizontal shear displacement and steeply inclined isoclinal folding. The D1 metamorphic fabrics developed at 486 ± 9 Ma on a retrograde temperature-path, from amphibolite (680800 °C, 0.50.9 GPa) to greenschist facies (300450 °C, 0.30.75 GPa) conditions. The subsequent syn-collisional event (D2) produced a subhorizontal foliation, top-to-SE-directed thrust deformation at the base of the Lyngen Magmatic Complex. D2 rock fabrics represent typical nappe stacking structures during the Scandian collisional stage (∼430 Ma). The vertical D1 structures are overprinted by D2 fabrics in the thrust contact region only. Mineral assemblages crystallizing during D2 indicate a transition from lower amphibolite to greenschist conditions. Thermobarometry suggests significant re-heating after D1, with D2 maximum conditions ∼650 °C and 1.1 GPa at the base of the Lyngen Magmatic Complex and ∼558610 °C and 0.81.3 GPa for the underlying graphite-bearing metasediments. Argon dating and the temperature difference between the Lyngen Magmatic Complex and the underlying units testify to out-of-sequence thrusting at 426 ± 7.5 Ma at the base of the Lyngen Magmatic Complex. The present results constrain the localization of the oceanic units of the North Norwegian Caledonides outboard and to the North of their present position. Consequently, stacking of uppermost units (likely of Laurentian origin) on top of the Lyngen Magmatic Complex occurred before their final emplacement onto the Reisa Nappe Complex (probably mostly Baltica-derived).

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引用次数: 0

Machine learning-based prediction of terrestrial heat-flow across mainland China

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-10 DOI: 10.1016/j.tecto.2025.230705

Chang Ni , Shan Xu , Xiangyun Hu , Xianchun Tang , Wenglong Zhou , Lingfeng Gao

Due to the limitations of interpolation methods in areas with sparse data points and highly heterogeneous spatial distributions, this study employs the Gradient Boosted Regression Tree (GBRT) method to predict the terrestrial heat-flow distribution across mainland China. The model is trained using available heat-flow data, with regional geophysical and geological information incorporated as constraints. A map of heat-flow with a resolution of 1° × 1° is obtained. Low heat-flow values (mean heat-flow of 50.7–52.2 mW/m²) are observed in the Tarim Craton, the Western Central Asian Orogen, and the Yangtze Craton, whereas the Tibetan Plateau exhibits high heat-flow values (mean heat-flow of about 79.0 mW/m²) due to the collision of the Indian Plate with the Eurasian Plate. Located at the junction of the Pacific, Eurasian and Philippine Sea plates, the Cathaysia Block shows a complex geothermal pattern with a sporadic distribution of high heat-flow due to heat transport presumably dominated by the subduction and upwelling of mantle.

由于插值法在数据点稀疏、空间分布高度异质的地区存在局限性，本研究采用梯度提升回归树（GBRT）方法预测中国大陆的陆地热流分布。该模型利用现有的热流数据进行训练，并将区域地球物理和地质信息作为约束条件。得到的热流图分辨率为 1° × 1°。塔里木克拉通、中亚西部造山带和长江克拉通的热流值较低（平均热流值为 50.7-52.2 mW/m2），而青藏高原由于印度板块与欧亚板块的碰撞，热流值较高（平均热流值约为 79.0 mW/m2）。位于太平洋板块、欧亚板块和菲律宾海板块交界处的国泰区块显示出复杂的地热模式，高热流零星分布，这可能是以地幔俯冲和上涌为主的热输送所致。

引用次数: 0

Fabric transition of olivine as the cause for an anisotropic seismic discontinuity in the mantle of the northern Slave craton, Canada

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-10 DOI: 10.1016/j.tecto.2025.230704

Qin Wang , Maya G. Kopylova , Yao Chen , Haojie Yan , McKensie Lynn Kilgore , Anne H. Peslier , Junwei Yang

The olivine fabric is commonly used to infer mantle flow directions from seismic anisotropy. Despite this, the response of olivine fabric to variations in high pressure, stress, olivine water content—and its subsequent impact on seismic anisotropy of the upper mantle — remains ambiguous. Here we studied 27 peridotite xenoliths from the adjacent Jericho and Muskox kimberlite pipes in the northern Slave craton (Canada) to correlate the olivine fabric with the seismic architecture of the lithospheric mantle. The xenoliths from depths of 70–190 km were analyzed for water content of olivine, and a subset of these samples were examined for the crystallographic preferred orientation of olivine and pyroxenes, major element compositions of minerals, and trace element compositions of garnet and clinopyroxene. Water content of olivine increases with depth, correlating with a decrease in the olivine Mg# (molar Mg/(Mg + Fe)) and increasing clinopyroxene modes. The dominant axial [010] olivine fabric coexists with two distinct fabrics above and below 120 km. These auxiliary fabrics transition from the A-type to the B-type, a change likely driven by increased pressure and the metasomatically-controlled high water content. This offers an explanation for an anisotropic seismic discontinuity observed at 120 km in the Northern Slave. The upper layer is defined by the preferred alignment of the fast [100] olivine axes along the N-S direction of the subhorizontal foliation plane, whereas in the lower layer the olivine [100] axes align parallel to the NE-SW direction. The discontinuity reflects the long, incremental formation process of the cratonic lithosphere that juxtaposes segments with distinct fossil flow directions, as evidenced by distinct fabric orientations. The upper layer may represent the older, depleted peridotites formed during the Mesoarchean craton stabilization, concurrently with the overlying crust. The deeper Proterozoic layer may have been added through accretion, subduction, plume-related melting, and modified by metasomatic events.

{"title":"Fabric transition of olivine as the cause for an anisotropic seismic discontinuity in the mantle of the northern Slave craton, Canada","authors":"Qin Wang , Maya G. Kopylova , Yao Chen , Haojie Yan , McKensie Lynn Kilgore , Anne H. Peslier , Junwei Yang","doi":"10.1016/j.tecto.2025.230704","DOIUrl":"10.1016/j.tecto.2025.230704","url":null,"abstract":"<div><div>The olivine fabric is commonly used to infer mantle flow directions from seismic anisotropy. Despite this, the response of olivine fabric to variations in high pressure, stress, olivine water content—and its subsequent impact on seismic anisotropy of the upper mantle — remains ambiguous. Here we studied 27 peridotite xenoliths from the adjacent Jericho and Muskox kimberlite pipes in the northern Slave craton (Canada) to correlate the olivine fabric with the seismic architecture of the lithospheric mantle. The xenoliths from depths of 70–190 km were analyzed for water content of olivine, and a subset of these samples were examined for the crystallographic preferred orientation of olivine and pyroxenes, major element compositions of minerals, and trace element compositions of garnet and clinopyroxene. Water content of olivine increases with depth, correlating with a decrease in the olivine Mg# (molar Mg/(Mg + Fe)) and increasing clinopyroxene modes. The dominant axial [010] olivine fabric coexists with two distinct fabrics above and below 120 km. These auxiliary fabrics transition from the A-type to the B-type, a change likely driven by increased pressure and the metasomatically-controlled high water content. This offers an explanation for an anisotropic seismic discontinuity observed at 120 km in the Northern Slave. The upper layer is defined by the preferred alignment of the fast [100] olivine axes along the N-S direction of the subhorizontal foliation plane, whereas in the lower layer the olivine [100] axes align parallel to the NE-SW direction. The discontinuity reflects the long, incremental formation process of the cratonic lithosphere that juxtaposes segments with distinct fossil flow directions, as evidenced by distinct fabric orientations. The upper layer may represent the older, depleted peridotites formed during the Mesoarchean craton stabilization, concurrently with the overlying crust. The deeper Proterozoic layer may have been added through accretion, subduction, plume-related melting, and modified by metasomatic events.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"903 ","pages":"Article 230704"},"PeriodicalIF":2.7,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Corrigendum to “Seismotectonic assessment of the High Atlas orogen: Implications for the 8 September Mw 6.8 El-Haouz earthquake” [Tectonophysics volume 895 (2025)].

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-09 DOI: 10.1016/j.tecto.2025.230683

Hamza Skikra , Abdelali Fadil , Youness Ouassanouan , Khalid Lakhouidsi , Abdelilah Tahayt , Abderrahmane Soulaimani , Lahcen El Moudnib

引用次数: 0

Spectral analysis of possible SES anomalies observed during aftershocks of the 2023 Kahramanmaraş Earthquakes

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-08 DOI: 10.1016/j.tecto.2025.230703

Mustafa Ulukavak , Sabri Mert İnanç

Seismic Electric Signal (SES) refers to pre-earthquake geoelectric anomalies that may serve as precursors to seismic events. The detection and analysis of SES variations are crucial for short-term earthquake forecast. This study examines possible geoelectric changes observed before the aftershocks following the major earthquakes of February 6, 2023, in the Kahramanmaraş region, located at the southwestern end of the Eastern Anatolian Fault Zone (EAFZ). Geoelectric variations were recorded at GEO_MUK station (37.1738°N, 38.9932°E) during the 30-day period after the main earthquake. The Fast Fourier Transform (FFT) was used to analyze the time series data, revealing potential anomalous frequency components on the days surrounding the earthquakes. Additionally, the Welch Method was applied to determine the power density of these frequencies before and after the seismic events. To assess the influence of geomagnetic activity, the Kp storm index was used to identify active and quiet space weather conditions. The results suggest that the geoelectric variations observed during sequential aftershocks may be short-term indicators of potential earthquake precursors. While these findings highlight the need for further investigation, they do not provide conclusive evidence that SES anomalies are definitive earthquake precursors. The study emphasizes the importance of continued research into the generation and transmission of SES signals, as well as their potential role in earthquake forecasting.

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引用次数: 0

Characterization of the northeastern region of the Neuquén Basin basement, Argentina, from 3D magnetotelluric inversion 通过三维磁位反演确定阿根廷内乌肯盆地基底东北部地区的特征

IF 2.7 3区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Tectonophysics

Pub Date : 2025-03-08 DOI: 10.1016/j.tecto.2025.230701

L. Guevara , G.A. Nicora , M. Armisen , M. Elías , F. Spath , F. Zyserman , G. Vergani

An electrical resistivity profile of the basement of the northeastern region of the Neuquén Basin and overlying units based on magnetotelluric data is presented. The data were obtained from the area where the basalts of the Payenia magmatic province cover the surface of the Eastern Platform near the basin edge. The exploration of the hydrocarbon potential in the Neuquén Basin has led to extensive investigations to identify structures that could act as traps and reservoirs. However, due to primary commercial objectives, most of these studies remain unpublished. While seismic methods are widely employed in geophysical surveys, their effectiveness is reduced in regions where shallow basalts are present. Additionally, in the study area, also the basement is shallow, restricting the depth of characterization to the first few hundred meters. Under such conditions, the resolution limitation and economic infeasibility of seismic methods make electromagnetic methods more suitable for subsurface prospecting. Thus, with the aim of determining the structures in the subsurface, 50 magnetotelluric sites were acquired. The three-dimensional inversion of the data revealed stepped changes in the resistivity units correlated with the basement and the layer above it. These resistivity steps could be associated with normal faults that accommodate hemigrabens parallel to the basin edge, in the NW-SE direction, mainly affecting the Choiyoi Group and Precuyo Group units. This result is consistent with the orientation of the fault system established in the southeastern sector of the study region. In the depocenters, a maximum sedimentary depth of 1 km was estimated. Finally, shallow regions with higher resistivity than their surroundings were also identified. These regions could be associated with hydrocarbon migration or even accumulation towards the basin edge.

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引用次数: 0