Journal of Structural Geology最新文献

Rift development at the Askja Fissure Swarm, Iceland 冰岛Askja裂缝群的裂谷发育

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2026-01-10 DOI: 10.1016/j.jsg.2026.105623

Fabio Luca Bonali , Martina Pedicini , Thomas R. Walter , Alessandro Tibaldi

Understanding how faulting and dyke intrusion interact to control rift development in volcanotectonic systems remains a key challenge, particularly in areas where multiple magma sources coexist. Here, we contribute to this topic by providing a high-resolution structural dataset for the Askja Fissure Swarm (AFS), one of the major rifts of the Northern Volcanic Zone of Iceland (NVZ), where central volcanoes and their associated dyke-fissure swarms act as magma plumbing systems and long-term eruption sources. We describe the Holocene structures of the AFS through the analysis of high-resolution remote sensing data and virtual field reconnaissance. We developed an inventory of 3749 individual structures, including dykes and fractures, mapped at a scale of 1:50,000, and systematically measured their strike, dip direction, length and kinematics. We recognized 395 eruptive fissures, 2301 extension dry fractures (fissures), and 1038 normal faults, of which 536 dip eastward and 502 westward. Along the main faults, we reconstructed the slip profiles, with the aim of evaluating the direction of along-axis fault and rift propagation. The overall dataset exhibits a predominant N–S to NNE–SSW strike, with an average strike of N17.5°E. Structure lengths vary from 10 m up to 13 km, with a mean of 445 m. Normal faults are generally longer than other structures, with a mean of 1042 m. With distance to the central volcanoes, we find the number of extension fractures and faults, their lengths and the slip profiles decrease. We interpret these characteristics as the effect of multiple dykes that laterally propagated outward from the magma chambers below Askja and Hrúthálsar central volcanoes. We also observed variation of fracture intensity and strike where the AFS intersects possibly hidden inherited transversal structures. Looking at the whole AFS, the tapering of fault slip profiles shows a dominant northward propagation of faults. This may indicate the superimposition of a regional northward propagation of the rift on the local effects of dykes and magma chambers, consistent with the northward spread of the NVZ.

了解断裂和岩脉侵入如何相互作用以控制火山构造系统中的裂谷发育仍然是一个关键的挑战，特别是在多个岩浆源共存的地区。在这里，我们通过为冰岛北部火山区（NVZ）的主要裂缝之一Askja裂缝群（AFS）提供高分辨率结构数据集来为这一主题做出贡献，其中中央火山及其相关的脉裂群充当岩浆管道系统和长期喷发源。通过对高分辨率遥感数据的分析和虚拟野外侦察，描述了AFS的全新世结构。我们编制了3749个独立构造的清单，包括堤防和裂缝，以1:5万的比例绘制，并系统地测量了它们的走向、倾斜方向、长度和运动学。发现喷发裂缝395条，伸展干裂缝2301条，正断层1038条，其中东倾536条，西倾502条。沿着主要断层重建了断层滑动剖面，目的是评估断层沿轴方向和裂谷的扩展。整个数据集以北南至北北-南南西走向为主，平均走向为N17.5°E。结构长度从10米到13公里不等，平均长度为445米。正断层一般比其他构造长，平均为1042米。随着离中心火山的距离增加，伸展断裂和断裂的数量、长度和滑动剖面减少。我们将这些特征解释为从Askja和Hrúthálsar中心火山下方的岩浆房向外横向传播的多个岩脉的影响。我们还观察到断裂强度和走向的变化，在AFS相交的地方可能隐藏着继承的横向构造。从整个AFS来看，断层滑动剖面的逐渐变细表明断层主要向北传播。这可能表明，裂谷的区域向北扩展叠加在岩脉和岩浆房的局部影响上，与NVZ向北扩展相一致。

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引用次数: 0

Extrusion of high-grade metamorphic and anatectic rocks during inclined transpression in the central Brasília Orogen, Western Gondwana 西冈瓦纳Brasília造山带中部斜挤压过程中高变质岩和无水岩的挤压作用

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2026-01-09 DOI: 10.1016/j.jsg.2026.105626

Fernando Resende Honorato , Marco Antônio Delinardo da Silva , Ticiano José Saraiva dos Santos , João Victor Oliveira Cunha , Ewerton Benetti Poloni , Pamela Pavanetto

Ancient and modern orogens are related to transpressional tectonics due to the Earth's spherical surface, often recording synchronous deformation, metamorphism, and anatexis. In the western Gondwana supercontinent, such relations are found in the Brasília Orogen, which formed from the collision between the Paranapanema, São Francisco-Congo, and Amazonian paleoplates during the Neoproterozoic Brasiliano/Pan-African Cycle. This study aims to investigate the deformational, metamorphic, and anatectic processes active in the central Brasília Orogen through field-based geological mapping and structural analysis, petrography, and U-Pb geochronology in zircon. The data show that the internal zone of the central Brasília Orogen underwent crustal shortening in the northeast-southwest direction, synchronous with lateral escape tectonics toward the southeast, suggesting an inclined transpressional context involving strain partitioning and the extrusion of deep-to-middle crustal rocks. The structural evolution was coeval with upper amphibolite to granulite facies metamorphism and anatexis, suggesting spatial and temporal relationships between structural fabrics, metamorphic and anatectic products. In this scenario, structures acted as primary controls of melt migration and granite emplacement, just as melt weakened the crust and facilitated structure nucleation. The Tonian (ca. 0.88 and 0.80 Ga) mafic protolith of the migmatitic orthogneiss and its leucosomes together with the migmatitic paragneiss and syntectonic granites confined the feedback loop between active ductile deformation, metamorphism and anatexis to the Cryogenian and Ediacaran periods (ca. 0.65 to 0.62 Ga), broadly constraining the interval of expressive crustal flow in the Brasilia Orogen.

由于地球是球形的，古代和现代造山带都与逆转构造有关，经常记录同步变形、变质作用和深熔作用。在冈瓦纳超大陆西部，这种关系在Brasília造山带中发现，该造山带是新元古代巴西利亚/泛非旋回期间由巴拉那帕内玛、弗朗西斯科-刚果古板块和亚马逊古板块碰撞形成的。本研究旨在通过野外地质填图、构造分析、岩石学、锆石U-Pb年代学等研究活动在Brasília造山带中部的变形、变质和析成岩过程。研究结果表明，Brasília造山带中部内带在东北—西南方向发生了地壳缩短，与东南方向的侧向逸出构造同步，表明该构造具有应变分区和深—中地壳挤压的斜转构造背景。构造演化与上部角闪岩-麻粒岩相变质和深熔作用同步，表明构造组构、变质和深熔产物之间存在时空关系。在这种情况下，构造是熔体迁移和花岗岩侵位的主要控制因素，就像熔体削弱地壳并促进构造成核一样。混合岩正长岩的东系（约0.88和0.80 Ga）基性原岩及其白色小体与混合岩副长岩和同构造花岗岩将活跃的韧性变形、变质作用和深熔作用的反馈回路限定在深冷系和埃迪卡拉系（约0.65 ~ 0.62 Ga），广泛地限制了巴西利亚造山带表现性地壳流动的间隔。

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引用次数: 0

Rethinking the crustal architecture of the Neoproterozoic gneiss domes in the Nubian Shield: Constraints from the Meatiq dome, Egypt 重新思考努比亚地盾新元古代片麻岩穹丘的地壳结构：来自埃及Meatiq穹丘的约束

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2026-01-03 DOI: 10.1016/j.jsg.2026.105615

Abdullah T. Mohammad , Yahia El Kazzaz

The Nubian Shield hosts amphibolite-grade, gneiss-cored domes surrounded by greenschist-grade island-arc and ophiolitic rocks. These domes record distinctly intense ductile deformation and higher metamorphism compared to adjacent rocks, yet their origin and geometry remain debated. Here we combine field observations, remote sensing, and structural–microstructural analyses to reassess the nature and architecture of these domes, focusing on the Meatiq dome in Central Eastern Desert of Egypt. Our results demonstrate that the dome represents a folded, thrust-related shear zone developed at mid-crustal levels within psammitic–pelitic metasediments overlain by ophiolitic and metavolcanic nappes. Microstructures record crystal-plastic deformation mechanisms at ∼670–450 °C with consistent top-to-NW shear indicators. Syn-kinematic emplacement of the Um Baanib and Abu Ziran granites occurred during NW-directed tectonic transport, with sub-magmatic microstructures recording the transition from magmatic to solid-state deformation. Both plutons display sheet-like geometries, controlled by lithological/rheological boundaries, and were later dissected by brittle thrust slices during doming. Although the Meatiq dome share some similarities with metamorphic core complexes, the absence of low-angle normal faults, rotational blocks, and migmatitic cores, combined with timing constraints, rules out core complex or diapiric origin. Instead, we argue that its domal geometry reflects thrust-related folding and multi-phase deformation associated with NW-directed tectonic transport during the East and West Gondwanaland collision (∼605–596 Ma), later modified by multiple Phanerozoic rifting phases. This evolutionary model highlights thrust-related tectonics as the primary driver of the Meatiq dome and prompts a reassessment of similar domes in the Nubian Shield. In addition, the results have broader implications for understanding gneiss-cored domes in orogenic belts worldwide and dynamic feedback between deformation and magmatism at mid-crustal shear zones.

努比亚地盾拥有角闪岩级、片麻岩芯的圆顶，周围环绕着绿片岩级岛弧和蛇绿岩。与邻近的岩石相比，这些圆顶记录了明显强烈的韧性变形和较高的变质作用，但它们的起源和几何形状仍有争议。在这里，我们结合实地观察、遥感和结构-微观结构分析来重新评估这些圆顶的性质和结构，重点是埃及中东部沙漠的Meatiq圆顶。我们的研究结果表明，在蛇绿岩和变质火山推覆体覆盖的泥质-泥质变质沉积层中，丘顶是一个褶皱的、逆冲相关的剪切带。显微结构记录了在~ 670-450°C的晶体塑性变形机制，具有一致的顶部到nw剪切指标。乌姆巴尼布和阿布兹兰花岗岩的同步运动学侵位发生在北西向构造搬运过程中，次岩浆微结构记录了岩浆向固态变形的过渡。这两个岩体都显示出薄片状的几何形状，受岩性/流变边界的控制，后来在穹隆过程中被脆性逆冲切片解剖。尽管Meatiq圆顶与变质核杂岩有一些相似之处，但由于缺乏低角度正断层、旋转块体和混染岩心，结合时间限制，排除了核杂岩或底辟成因的可能性。相反，我们认为其隆起的几何形状反映了东、西Gondwanaland碰撞（~ 605-596 Ma）期间与北西向构造运输有关的逆冲相关的褶皱和多期变形，后来被多个显生宙裂陷期所修正。这一演化模型强调了与逆冲相关的构造是Meatiq穹窿的主要驱动力，并促使人们重新评估努比亚地盾中类似的穹窿。此外，研究结果对于认识世界范围内造山带的片麻岩核圆顶以及中地壳剪切带变形与岩浆活动的动态反馈具有更广泛的意义。

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引用次数: 0

Slab kinematics and strain localization in NE China: Polyphase deformation of the Hulin Complex during Late Mesozoic subduction 中国东北板块运动与应变局部化：晚中生代俯冲期间虎林杂岩的多期变形

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2026-01-02 DOI: 10.1016/j.jsg.2025.105614

Wei Pi , Han Zheng , Jian Zhang , Zhiyuan He , Johan De Grave , Ian P. Cawood , Yong Liang , Heng Peng , Guochun Zhao

Crustal shear zones in Northeast China preserve a critical record of Paleo-Pacific subduction, yet distinguishing the superimposed tectonic fabrics remains a challenge. We resolved this by reconstructing the structural and thermal history of the Hulin Complex, linking local deformation directly to specific slab dynamics. During the Late Jurassic to Early Cretaceous (D₁: ca. 160–130 Ma), a moderate oblique subduction angle (∼30–40°) drove NE–SW sinistral transpression. This phase produced distributed general shear (Flinn's k = 0.73–0.91; W_k = 0.64–0.67) under mid-crustal conditions (∼350–500 °C), accommodated by quartz rhomb <a> and prism <a> slip at differential stresses of 15–18 MPa. In the Cretaceous (D₂: ca. 130–85 Ma), accelerated SE-directed slab rollback stretched the lithosphere, triggering regional extension (Flinn's k = 0.85–1.01; W_k = 0.57–0.62). Strain localized into weak, mica-rich zones (>15 vol%) as differential stresses dropped to 13–14 MPa and temperatures cooled to 300–400 °C. This extension facilitated synchronous magmatism. By the Late Cretaceous (D₃: ca. 85–68 Ma), a shift to W–NW subduction created a lower obliquity angle (∼20–30°). This renewed dextral transpression reactivated older structures in the mid-to-lower crust (≤300–400 °C) but at significantly higher stresses (21–34 MPa). Quartz fabrics shifted to basal <a> slip, reflecting strain repartitioning (Flinn's k = 0.63–0.76; W_k = 0.67–0.71). Our findings demonstrate that shear zone evolution is governed by specific subduction parameters: (1) shallower slab dips enhance coupling to localize strain; (2) rapid rollback weakens the lithosphere to drive extension; and (3) high convergence obliquity (angles <30°) amplifies the simple shear component. Thus, the Hulin Complex acts as a sensitive rheological recorder, capturing the changing tempo and geometry of the subducting slab.

中国东北的地壳剪切带保存了古太平洋俯冲的重要记录，但区分叠合构造仍然是一个挑战。我们通过重建虎林杂岩的结构和热历史来解决这个问题，将局部变形直接与特定的板动力联系起来。晚侏罗世至早白垩世（D1：约160 ~ 130 Ma），一个中等斜向俯冲角（~ 30 ~ 40°）驱动了NE-SW左旋转动。该相在中地壳条件下（~ 350 ~ 500°C）产生了分布的总剪切（Flinn’s k = 0.73-0.91; Wk = 0.64-0.67），在15 ~ 18 MPa的差应力下，由石英菱形和棱形滑移（<a>；和棱镜<；a>；滑移）所适应。在白垩纪（D2：约130 ~ 85 Ma），加速的东南向板块回滚拉伸了岩石圈，引发了区域伸展（Flinn’s k = 0.85 ~ 1.01; Wk = 0.57 ~ 0.62）。当差应力降至13-14 MPa，温度降至300-400°C时，应变局部定位到弱的富云母区（>15 vol%）。这种扩展促进了同步岩浆活动。到晚白垩世（D3：约85-68 Ma），向W-NW俯冲的转变产生了较低的倾角（~ 20-30°）。这种更新的右旋转活动重新激活了中下地壳（≤300-400°C）的旧构造，但在明显更高的应力下（21-34 MPa）。石英织物向基底滑动，反映应变重新分配（Flinn’s k = 0.63-0.76; Wk = 0.67-0.71）。研究结果表明，剪切带的演化受特定俯冲参数的控制：(1)较浅的板块倾角增强了局部应变的耦合；(2)快速回滚削弱岩石圈，推动伸展；(3)高辐合倾角（角<；30°）放大了简单剪切分量。因此，虎林杂岩充当了一个敏感的流变记录仪，捕捉俯冲板块的变化速度和几何形状。

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引用次数: 0

Investigating the generation of transport-parallel gradients in ductile strain and kinematic vorticity in the footwalls of metamorphic core complexes: Insights from the Northern Snake Range, Nevada, USA 研究变质岩心杂岩下盘韧性应变和运动涡度的输运平行梯度的产生：来自美国内华达州北蛇岭的见解

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2025-12-26 DOI: 10.1016/j.jsg.2025.105611

Aurora E. Rosenberger , Sean P. Long , Nolan Blackford , Johannes Haemmerli , Kyle P. Larson , Brianna Dowler , Scott Jess

Several metamorphic core complexes exhibit structural asymmetry in their exhumed footwalls, with ductile strain, crystallographic preferred orientation (CPO) intensity, and/or mean kinematic vorticity (W_m) increasing in the direction of detachment fault displacement. Here, we investigate the Northern Snake Range metamorphic core complex in Nevada, to explore the processes that are the most influential for generating transport-parallel strain gradients in detachment fault footwalls. Eocene-Oligocene tectonic strain (Rs), lineation-parallel extension, and foliation-normal thinning in the Northern Snake Range increase eastward from 1.5–1.6 to 240–820, 25–30 % to 1400–2400 %, and 15–21 % to 93–95 %, respectively (assuming no volume change). CPO intensity parameters (cylindricity and J_PF index) increase eastward from 0.45 to 0.90–0.95 and 1.40 to 2.64–6.40, respectively, and average W_m increases eastward from 0.26–0.40 (72–82 % pure shear) to 0.77–0.83 (56–63 % simple shear). Restoration of a strain model supported by a range-wide cross-section defines 17.9 km (470 %) of Eocene-Oligocene ductile extension. Published footwall cooling histories demonstrate an eastward progression of exhumation-related cooling, driven by unroofing via top-down-to-ESE displacement on the master detachment. This progressive unroofing resulted in an eastward increase in the residence time of quartz-rich footwall rocks at temperatures above ∼300 °C (and thus a longer ductile strain history on the eastern side of the range), which we interpret was a 1st-order factor for generating the eastward increases in strain, CPO intensity, and W_m. The Northern Snake Range is an excellent case study that demonstrates the potential for generation of pronounced transport-parallel structural asymmetry in metamorphic core complexes that are exhumed by high-displacement detachment faults.

一些变质岩心杂岩体在其下盘表现出结构不对称性，韧性应变、晶体优选取向（CPO）强度和/或平均运动涡量（Wm）沿滑脱断层位移方向增大。本文以美国内华达州北蛇岭变质核杂岩为研究对象，探讨对滑脱断层下盘形成输运平行应变梯度影响最大的过程。北蛇岭始新世—渐新世构造应变（Rs）、线—平行伸展和片理—正常减薄分别从1.5 ~ 1.6增加到240 ~ 820、25 ~ 30%增加到1400 ~ 2400、15 ~ 21%增加到93 ~ 95%（假设体积没有变化）。CPO强度参数（圆柱度和JPF指数）分别从0.45增加到0.90-0.95和1.40增加到2.64-6.40，平均Wm从0.26-0.40（72 - 82%纯剪切）增加到0.77-0.83（56 - 63%单纯剪切）。由全范围截面支持的应变模型的恢复确定了17.9公里（470%）的始新世-渐新世延展性延伸。已发表的下盘冷却历史表明，与挖掘相关的冷却过程是向东推进的，这是由主分离层自上而下至ese位移的拆顶所驱动的。这种渐进式去顶导致富石英下盘岩石在温度高于~ 300°C时的停留时间向东增加（因此在该范围的东侧有更长的韧性应变历史），我们解释这是导致应变、CPO强度和Wm向东增加的一级因素。北蛇岭是一个很好的研究案例，它证明了在高位移脱离断层挖掘出的变质岩心杂岩中可能产生明显的输运平行构造不对称。

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引用次数: 0

Pre-Neogene tectonics and early broken foreland basin stages in the Bermejo basin 贝尔梅霍盆地前新近纪构造与早期破碎前陆盆地阶段

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2025-12-23 DOI: 10.1016/j.jsg.2025.105612

Marcelo Gonzalez , Federico Lince Klinger , Cinthya Moreno , Franco Clavel , Federico Morales , Cristian Ortiz , Guido Gianni , Miguel Ramos

Broken foreland basins develop in response to far-field compressional stresses from active margins, resulting in deep-seated intraplate contractional structures that fragment the original foreland basin. This study investigates the tectono-sedimentary evolution of the Bermejo Basin, the first recognized broken foreland basin in South America, situated between the Eastern Precordillera and Western Pampean Ranges. Through the reprocessing of seismic data and gravity analyses, we identify three main tectono-sedimentary stages: Stage 1 (Pre-Neogene), Stage 2 (19-4 Ma), and Stage 3 (4–2.5 Ma to Present). Stage 1 generated structures that were buried and subsequently reactivated during Stage 2. This latter stage marked a significant reconfiguration of the basin with progressive northward propagation of compressional structures and a major shift in basin polarity around 6-5 Ma. These stages correspond to varying configurations of the Andean subduction zone, with strong foreland compression linked to flat subduction. However, the mild initial compression of a key structure active since 19-17 Ma, as evidenced by syntectonic strata, suggests that the foreland remained responsive to compressional forces transmitted from the plate margin during episodes of normal subduction. Our findings underscore the previously unrecognized role of inherited (or pre-Andean) compression in the evolution of the Bermejo Basin and provide evidence for a hybrid deformation style affecting the Eastern Precordillera, impacting the western margin of this basin. This study emphasizes the need for updated regional kinematic models that account for the interplay of ancient and more recent tectonic processes in the Bermejo Basin. Finally, our observations indicate that inherited compressional structures, such as the Carboniferous-Permian faults and the early Miocene Alto del Jumeal Range, have played a significant role in guiding subsequent deformation and sedimentation within the Bermejo basin.

破碎前陆盆地是在活动边缘的远场挤压应力作用下发育的，形成了将原始前陆盆地破碎的深层板内收缩构造。本文研究了Bermejo盆地的构造-沉积演化。Bermejo盆地是南美洲第一个被发现的破碎前陆盆地，位于东部Precordillera山脉和西部Pampean山脉之间。通过对地震资料的再处理和重力分析，我们确定了三个主要的构造沉积阶段：第1阶段（前新近纪）、第2阶段（19-4 Ma）和第3阶段（4-2.5 Ma至今）。第一阶段产生了埋藏的结构，随后在第二阶段重新激活。这一阶段标志着盆地的重大重构，挤压构造向北扩展，盆地极性在6-5 Ma左右发生重大转变。这些阶段对应于安第斯俯冲带的不同构造，强烈的前陆挤压与平坦的俯冲有关。然而，同构造地层表明，19-17 Ma以来活跃的关键构造的轻微初始压缩表明，在正常俯冲期间，前陆仍然对板块边缘传递的挤压力作出反应。我们的发现强调了继承（或前安第斯）挤压在Bermejo盆地演化中的作用，并为影响东部前科迪勒拉的混合变形样式提供了证据，影响了该盆地的西缘。这项研究强调需要更新的区域运动学模型，以解释贝尔梅霍盆地古代和近代构造过程的相互作用。结果表明，石炭-二叠纪断裂和早中新世Alto del Jumeal山脉等挤压构造对Bermejo盆地的后续变形和沉积起着重要的指导作用。

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引用次数: 0

Deformation evolution of the rifting and positive inversion in the Central African Shear Zone: Insights from Analogue Modelling 中非剪切带裂陷和正反转的变形演化：来自模拟模拟的启示

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2025-12-18 DOI: 10.1016/j.jsg.2025.105605

Lirong Dou , Xinshun Zhang , Chuanbo Shen , Yebo Du , Li Wang , Xiang Ge , Huahua Gao , Yu Yang

Investigating the deformation evolution of rifting, strike-slip faulting, and positive inversion within the Central African Shear Zone (CASZ) is crucial for understanding regional tectonic evolution, dynamic processes, and improving the exploration of hydrocarbon-rich basins. To better understand the deformation evolution of the CASZ, three brittle/ductile analog models with different block angles were tested. The results indicate that under NE–SW extensional stress: (1) rifting intensity in the CASZ decreases progressively from west to east, with the Doba Basin experiencing the strongest rifting, followed by the Doseo Basin, and the weakest rifting occurring in the Salamat Basin; (2) significant strike-slip deformation is concentrated primarily in the Doseo Basin, followed by the Salamat Basin, with minimal strike-slip deformation in the Doba Basin; and (3) strong positive inversion occurs near boundary regions of the CASZ—predominantly along the basin boundaries in the Doba Basin, whereas in the Doseo and Salamat Basins, it is more pronounced in the central depression areas.

研究中非剪切带内裂陷、走滑断裂和正反转的变形演化，对于认识区域构造演化和动力过程，提高油气勘探水平具有重要意义。为了更好地了解CASZ的变形演变，测试了3种不同块体角度的脆性/韧性模拟模型。结果表明，在NE-SW张拉应力作用下：(1)CASZ内裂陷强度自西向东逐渐减弱，其中断陷最强的是Doba盆地，其次是Doseo盆地，最弱的是Salamat盆地；(2)走滑变形主要集中在多西盆地，其次是萨拉马特盆地，多巴盆地走滑变形最小；(3)强正反转发生在casz边界附近，在Doba盆地以沿盆地边界为主，而在Doseo和Salamat盆地，在中央坳陷区更为明显。

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引用次数: 0

Clayrock deformation and permeability: insights from natural observations and experimental tests 粘土岩石变形和渗透性：来自自然观察和实验测试的见解

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2025-12-17 DOI: 10.1016/j.jsg.2025.105610

Adrien Damon , Roger Soliva , Jean Busson , Christopher Wibberley , Céline Fliedner , Frédéric Bourgeois , Frédéric Ego

We propose a model of the permeability behavior of clayrocks based on a review of plastic deformation observed in the field and permeability measurements in reactivation tests of fractures and faults. Firstly, we classify structures observed in the field according to their deformation mode and propose a model of clayrock deformation relative to usual mechanical concepts described in the literature. Secondly, we evidence controls on clayrock fracture/fault permeability by the stress conditions of the reactivated structures, the amount of shear displacement along them, and the mechanical properties of the clayrock. Finally, we formulate our model based on similarities in the concepts of clayrock deformation and the experimental evolution of clayrock fracture/fault permeability. This model links quantitative data on permeability evolution to deformation mechanisms, defining the permeability behavior of clayrocks, which was lacking in the literature until now. We highlight the dependence of this behavior on the stress and shear conditions, and demonstrate that the ratio of effective normal stress (

σ_{n}^{'}

) to the Unconfined Compressive Strength (UCS) of the clayrock can be used to describe this behavior. This model can be used in the assessment of clayrock formation sealing capacity in the context of geological storage. Particularly, the use of the UCS has the advantage of integrating important geological parameters in this assessment, such as the clay content or consolidation history. According to this model, we recommend to preserve a

σ_{n}^{'} / U C S

level larger than 0.5 in order to avoid a significant permeability increasing behavior associated with reactivation.

我们在回顾了现场观察到的塑性变形和裂缝和断层再激活试验中的渗透率测量的基础上，提出了粘土岩渗透行为的模型。首先，我们根据变形模式对现场观察到的结构进行分类，并相对于文献中描述的通常力学概念提出了粘土岩变形模型。其次，通过活化构造的应力条件、沿构造的剪切位移量和粘土岩的力学性质来证明对粘土岩破裂/断层渗透性的控制。最后，基于粘土岩变形概念的相似性和粘土岩裂缝/断层渗透率的实验演化，建立了我们的模型。该模型将渗透率演化的定量数据与变形机制联系起来，定义了粘土岩的渗透率行为，这是迄今为止文献中所缺乏的。我们强调了这种行为对应力和剪切条件的依赖性，并证明了有效正应力（σn’）与粘土岩的无侧限抗压强度（UCS）的比值可以用来描述这种行为。该模型可用于地质储层条件下粘土岩储层封闭性评价。特别是，使用UCS具有在评估中整合重要地质参数的优势，例如粘土含量或固结历史。根据该模型，我们建议保持σn′/UCS大于0.5，以避免与再活化相关的显著渗透率增加行为。

{"title":"Clayrock deformation and permeability: insights from natural observations and experimental tests","authors":"Adrien Damon , Roger Soliva , Jean Busson , Christopher Wibberley , Céline Fliedner , Frédéric Bourgeois , Frédéric Ego","doi":"10.1016/j.jsg.2025.105610","DOIUrl":"10.1016/j.jsg.2025.105610","url":null,"abstract":"<div><div>We propose a model of the permeability behavior of clayrocks based on a review of plastic deformation observed in the field and permeability measurements in reactivation tests of fractures and faults. Firstly, we classify structures observed in the field according to their deformation mode and propose a model of clayrock deformation relative to usual mechanical concepts described in the literature. Secondly, we evidence controls on clayrock fracture/fault permeability by the stress conditions of the reactivated structures, the amount of shear displacement along them, and the mechanical properties of the clayrock. Finally, we formulate our model based on similarities in the concepts of clayrock deformation and the experimental evolution of clayrock fracture/fault permeability. This model links quantitative data on permeability evolution to deformation mechanisms, defining the permeability behavior of clayrocks, which was lacking in the literature until now. We highlight the dependence of this behavior on the stress and shear conditions, and demonstrate that the ratio of effective normal stress (<span><math><mrow><msubsup><mi>σ</mi><mi>n</mi><mo>′</mo></msubsup></mrow></math></span>) to the Unconfined Compressive Strength (UCS) of the clayrock can be used to describe this behavior. This model can be used in the assessment of clayrock formation sealing capacity in the context of geological storage. Particularly, the use of the UCS has the advantage of integrating important geological parameters in this assessment, such as the clay content or consolidation history. According to this model, we recommend to preserve a <span><math><mrow><msubsup><mi>σ</mi><mi>n</mi><mo>′</mo></msubsup><mo>/</mo><mi>U</mi><mi>C</mi><mi>S</mi></mrow></math></span> level larger than 0.5 in order to avoid a significant permeability increasing behavior associated with reactivation.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"204 ","pages":"Article 105610"},"PeriodicalIF":2.9,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145771939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Comparative studies of salt pillows in proximity to the Ringkøbing-Fyn High, Denmark 丹麦Ringkøbing-Fyn高地附近盐枕的比较研究

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2025-12-15 DOI: 10.1016/j.jsg.2025.105609

Cecilia E.B. Nielsen, Ole R. Clausen

The salt structures in Denmark have become of increased interest for the current Carbon Capture and Storage (CCS) investigations, with most of the prospecting areas being in close relation to the structures. In this study we have investigated three salt pillows located on both sides of the Ringkøbing-Fyn High (RFH), Denmark, with focus on the timing and direction of salt movement. With the use of interpretation and restoration software, we have interpreted multiple 2D seismic lines and made a structural restoration of a defining line for each structure to determine the evolution of the salt movement. Our results show that the structures closest to the RFH have been created by Triassic gravitational gliding of the salt away from the high, while the salt further north most likely initiated by a combination of differential loading and local tectonics during the same period. Salt reactivation is more pronounced for the structures located north of the RFH, especially showing salt reactivation after the deposition of the late Cretaceous Chalk Group indicating a Cenozoic process only affecting the salt structures north of the high. However, the overall deformation of the three structures shows similar patterns, indicating that they all might represent structures located at the border zone of the Permian Zechstein salt basins, thus pushing the influence of the Sorgenfrei-Tornquist Zone in the Norwegian-Danish Basin much further west in the Norwegian-Danish basin than formerly understood.

丹麦的盐结构已成为当前碳捕集与封存（CCS）调查中日益增加的兴趣，大多数勘探区都与盐结构密切相关。在这项研究中，我们调查了位于丹麦Ringkøbing-Fyn高地（RFH）两侧的三个盐枕，重点研究了盐运动的时间和方向。利用解释和恢复软件，我们解释了多条二维地震线，并对每个结构的定义线进行了结构恢复，以确定盐运动的演变。我们的研究结果表明，最接近RFH的构造是由三叠纪盐远离高点的重力滑动造成的，而更北的盐很可能是由同一时期的差异荷载和局部构造共同形成的。盐的再激活作用在RFH以北的构造中更为明显，特别是在晚白垩世白垩群沉积后，表明新生代的盐的再激活作用只影响到高北的盐构造。然而，三个构造的整体变形模式相似，表明它们都可能代表了位于二叠纪Zechstein盐盆地边界带的构造，从而将挪威-丹麦盆地的Sorgenfrei-Tornquist带的影响推到了挪威-丹麦盆地的西部，比以前认识的要远得多。

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引用次数: 0

Quantifying finite strain in the poly-deformed Lansdowne Klippe, Garhwal Himalaya, India: An appraisal of popular strain estimation techniques 定量有限应变在多变形的Lansdowne Klippe， Garhwal喜马拉雅，印度：流行的应变估计技术的评价

IF 2.9 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology

Pub Date : 2025-12-11 DOI: 10.1016/j.jsg.2025.105585

Sayandeep Banerjee , Sayan Maity , Ashish Rawat , Virendra Rana , Yaspal Sundriyal , Hari B. Srivastava

Understanding finite strain in poly-deformed terranes remains a challenge due to multiple deformation phases, impacting accurate estimation. This study presents a comparative analysis of four distinct techniques (Rf/Φ, Fry's, Panozzo, and AMS-based strain estimation) to estimate the finite strain in the Lansdowne Klippe of the Garhwal Himalaya, India. In the estimation of strain, complexities might arise due to the inherent difficulties in assessing the original shape of strain indicators in areas with a history of multiple deformations. Such challenges significantly affect the precision of finite strain estimation, leading to inconsistencies in the obtained values. By analysing the quantitative and qualitative differences among the methodologies, this study reveals the discrepancies in determining 2-D finite strain and respective strain ellipses. The present attempt is the first rigorous multi-method comparison for quantifying strain within a poly-deformed klippe in the Himalayan orogen. In our comparative analysis, Rf/Φ and Fry methods yielded the highest finite strains (Rs ∼1.7–2.3), whereas the Panozzo method gave lower values (Rs ∼1.1–2.0). AMS-derived anisotropy (Pj ∼1.05–1.2) corresponds to only low finite strain. These systematic method-dependent differences underscore that strain magnitudes in a polyphase terrane are strongly influenced by the chosen technique. Our findings also highlight the inherent inconsistencies and limitations in estimating finite strain in regions with polyphase deformation.

在多变形地形中，由于存在多个变形阶段，因此理解有限应变仍然是一个挑战，影响了准确的估计。本研究提出了四种不同的技术（Rf/Φ， Fry's， Panozzo和基于ams的应变估计）的比较分析，以估计印度Garhwal喜马拉雅地区Lansdowne Klippe的有限应变。在应变估计中，由于在具有多次变形历史的区域中评估应变指标的原始形状存在固有的困难，可能会产生复杂性。这些挑战严重影响了有限应变估计的精度，导致所得值不一致。通过分析这些方法在定量和定性上的差异，揭示了在确定二维有限应变和各自的应变椭圆时的差异。目前的尝试是第一次对喜马拉雅造山带多变形断裂带的应变进行定量的严格的多方法比较。在我们的比较分析中，Rf/Φ和Fry方法产生了最高的有限应变（Rs ~ 1.7-2.3），而Panozzo方法给出了较低的值（Rs ~ 1.1-2.0）。ams衍生的各向异性（Pj ~ 1.05-1.2）只对应于低有限应变。这些系统的方法相关的差异强调了多相岩层中的应变大小受到所选技术的强烈影响。我们的研究结果还强调了在多相变形区域估计有限应变的固有不一致性和局限性。

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引用次数: 0