Journal of Structural Geology最新文献

{"title":"Lattice preferred orientation of pyrrhotite in a sheeted vein complex of the Mokrsko-West gold deposit of Central Bohemia as investigated by the anisotropy of in-phase and out-of-phase magnetic susceptibility","authors":"František Hrouda ,&nbsp;Jan Franěk ,&nbsp;Ondřej Švagera ,&nbsp;Marta Chlupáčová ,&nbsp;Jaromír Hanák","doi":"10.1016/j.jsg.2025.105459","DOIUrl":"10.1016/j.jsg.2025.105459","url":null,"abstract":"<div><div>Preferred orientation of pyrrhotite by crystal lattice in varied mineralized rocks was investigated by means of the anisotropy of magnetic susceptibility. The study area is mineralized contact of Neo-Proterozoic meta-volcanics with Variscan Sázava tonalite in the Central Bohemia. The contact crops out in the <em>Josef Gallery</em> located in the Mokrsko-West gold deposit. Magnetism of the investigated rocks is dominantly carried by pyrrhotite associated with the Mokrsko-West gold mineralization. In meta-volcanics, pyrrhotite basal planes are parallel to the cleavage and were preferably oriented through recrystallization or neocrystallization in an anisotropic stress field and/or through mechanical reorientation due to ductile deformation of the host rock. In tonalite, pyrrhotite basal planes are parallel to dominating steep joints. This preferred orientation evidently originated through oriented crystallization from mineralizing fluids into microcracks hosting quartz veinlets. Steep to vertical intersections come from differently striking vertical joints hosting mineralizations.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"198 ","pages":"Article 105459"},"PeriodicalIF":2.6,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072444","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}

{"title":"Microstructures and deformation mechanisms of mass transport-related, soft-sediment folds","authors":"Clara Costa Polanski,&nbsp;Barbara Trzaskos,&nbsp;Mérolyn Camila Naves de Lima Rodrigues,&nbsp;Fernando Farias Vesely","doi":"10.1016/j.jsg.2025.105456","DOIUrl":"10.1016/j.jsg.2025.105456","url":null,"abstract":"<div><div>Soft-sediment deformation structures (SSDS) are the result of deformation in sedimentary material before significant diagenesis or lithification, and they can result from various triggers, including mass transport (slides, slumps and debris flows). There are several previous works on SSDS within mass-transport deposits (MTDs) and their deformation mechanisms, however most of them consider only macro-to mesoscale data (outcrops and hand specimens), resulting in a lack of microanalysis of deformation mechanisms. In this work we investigate microstructures aiming to interpret deformation mechanisms involved in the formation of folds commonly found in MTDs, aiming to create a compendium of these structures. Using samples from two evolved (highly homogeneized) MTDs in the Permo-Carboniferous Itararé Group, Paraná Basin, southern Brazil, we analyze structural styles in thin sections and discuss their occurrence, geometry and deformation mechanisms. Structural analysis reveals a diverse range of folds resulted from buckling-dominated and bending-dominated folding processes, whose formation was influenced by variations in sediment cohesion, layer thickness and rheology. The absence of cataclasis and early diagenetic minerals, along with grain alignment to fault planes and fold axial surfaces, indicates that deformation occurred under low confining stress prior to lithification, driven by granular flow. Local variations in cohesion within sand- and silt-rich layers are attributed to pore-fluid pressure fluctuations. The findings suggest that the primary deformation mechanism involves progressive shearing of water-saturated sediment, enhanced by liquefaction and fluidization processes.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"198 ","pages":"Article 105456"},"PeriodicalIF":2.6,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068498","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}

{"title":"The red river fault zone and its deep structural characteristics revealed by high-resolution seismic data in the Yinggehai basin, South China sea","authors":"Tao Wu ,&nbsp;Jianxiang Pei ,&nbsp;Yongtao Fu ,&nbsp;Dun Deng ,&nbsp;Guanfei Chen ,&nbsp;Tao Xu ,&nbsp;Dingding Wang ,&nbsp;Zhangguo Zhou ,&nbsp;Wanyin Wang","doi":"10.1016/j.jsg.2025.105457","DOIUrl":"10.1016/j.jsg.2025.105457","url":null,"abstract":"<div><div>With the Red River Fault Zone (RRFZ) as the northern boundary, the lateral extrusion of the Indochina Block relative to the South China Block is a response and accommodation to the substantial deformation resulted from the collision and convergence of the India-Eurasia plates. However, the tectonic nature of the RRFZ remains a topic of debate. The Cenozoic Yinggehai Basin (YGHB), controlled by the RRFZ, preserves the tectonic history of the region in its thick strata. Analysis of high-resolution seismic data indicates that the RRFZ, including the No.1 Fault, Central Fault, and other basement faults, intersects the Moho, suggesting its lithospheric-scale nature. Strike-slip shearing along the RRFZ in the YGHB dates back to approximately 40.4 Ma ago, as inferred by the T83 horizon distinguished for the first time. The Moho surface exhibits uplift and gentle undulations within the Central Depression (CD), with a minimum depth less than 19 km. In the diapir zone of the CD, crustal thickness ranges from 4 to 5 km, with stretching coefficient of 5.2–6.5, indicating significant thinning and hyper-extension, evidenced by the low-angle normal faults in the lower crust. Strike-slip shearing along the Central Fault and No.1 Fault, coupled with multiple structural inversions, facilitated the development of structural inversion in the northern YGHB. A comprehensive understanding of the RRFZ is crucial for oil and gas exploration in the YGHB.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"198 ","pages":"Article 105457"},"PeriodicalIF":2.6,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936236","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}

{"title":"Geometric forward modeling of thrust systems underlying shortening landforms on Mercury","authors":"Stephan R. Loveless ,&nbsp;Christian Klimczak ,&nbsp;Kelsey T. Crane ,&nbsp;Paul K. Byrne","doi":"10.1016/j.jsg.2025.105449","DOIUrl":"10.1016/j.jsg.2025.105449","url":null,"abstract":"<div><div>Mercury hosts thousands of shortening landforms that are widespread across the entire planet. The shortening is widely accepted to be caused by a combination of thrust faulting and folding, resulting from the global contraction of Mercury caused by long, sustained cooling. Most shortening landforms on Mercury's surface have been classified into one of two groups: lobate scarps or wrinkle ridges. There is no distinct statistical difference in the surface morphology of these shortening landform classifications. Only a small subset of shortening landforms are clear-endmember wrinkle ridges and lobate scarps. The difference between geomorphic manifestations of shortening landforms may be governed entirely by the thrust systems and associated folding that form them. We therefore model thrust systems associated with 55 lobate scarp and wrinkle ridge endmember shortening landforms found across the surface of Mercury. Structures were modeled in 2D sections below the topographic profiles of landforms with the greatest structural relief. Models utilized the fault-bend fold algorithm in the MOVE geologic modeling software. Once models matched the observed topography and shortening strain, fault geometric parameters, such as number of structures, dip, depth extent of faulting, height, etc., were extracted and compiled for all structures. Our modeling shows that Mercury hosts a wide range of complex thrust systems, including single, listric faults, imbricate thrusts, and pop-up structures. In particular, the morphologies of lobate scarps endmember structures are best explained by models of a single, listric fault, whereas most wrinkle ridge endmember structures require more than one fault. We identify a large overlap in the variation of fault geometric parameters for both wrinkle ridge and lobate scarp archetypes, confirming the results of our previous geomorphic analysis that shortening landforms do not comprise two distinct categories. The overlap in geometric parameters suggests that the formation mechanisms of lobate scarp and wrinkle ridge endmember structures are the same.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"198 ","pages":"Article 105449"},"PeriodicalIF":2.6,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924777","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}

{"title":"The latest surface rupture along the western segment of the Qilian–Haiyuan fault and its implications","authors":"Yameng Wen ,&nbsp;Daoyang Yuan ,&nbsp;Jinchao Yu ,&nbsp;Yanxiu Shao ,&nbsp;Shuwu Li ,&nbsp;Youlin Wang ,&nbsp;Qianhao Xiao","doi":"10.1016/j.jsg.2025.105448","DOIUrl":"10.1016/j.jsg.2025.105448","url":null,"abstract":"<div><div>The Qilian‒Haiyuan fault is a boundary fault with strike slipping in the Qilian Shan (Shan means mountain or mountain range in Chinese) on the northeastern Tibetan Plateau. Several strong earthquakes (M ≥ 7) have occurred in this fault zone, and the risk of future major earthquakes is highly concerning. We identified a seismic surface rupture zone of unknown age at the Halahu fault, which is located at the western end of the Qilian‒Haiyuan fault. The Halahu fault plays a crucial role in structural transformation at the westernmost point of the Qilian‒Haiyuan fault zone, and historical seismic records are vital for assessing the future seismic risk associated with the fault. We found via field investigation that the existing length of the rupture zone is more than 24 km, which is characterized mainly by cracks, the offset of the trench, and the offset of terrace edges. Twenty-eight left-lateral coseismic offsets were determined using field measurements and UAV image analysis, with a minimum offset of 0.6±0.1 m and a maximum offset of 2.5±0.2 m. Historical earthquake records confirm that the surface rupture zone was caused by the M6½ earthquake that occurred east of Hala Lake on July 14, 1930 east of Hala Lake; however, the magnitude of that earthquake should be revised to be approximately M6¾ on the basis of field survey data. Research has shown that major earthquakes have shifted from the Bayan Har active block to the Qinghai‒Tibet block boundary fault zone. This study identified and dated earthquake surface rupture zones, offering essential guidance for future research and assessments of fault earthquake risk. Our results indicate that the Halahu, Tuolaishan, and Jinqianghe‒Laohushan faults have high potential for strong future earthquakes.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"198 ","pages":"Article 105448"},"PeriodicalIF":2.6,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942809","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}

{"title":"Failure mode transition in brittle boudinage: Effects of cohesion, confining pressure, and layer thickness","authors":"Steffen Abe ,&nbsp;Christoph von Hagke ,&nbsp;Simon Virgo ,&nbsp;Janos L. Urai","doi":"10.1016/j.jsg.2025.105427","DOIUrl":"10.1016/j.jsg.2025.105427","url":null,"abstract":"<div><div>Boudins are ubiquitous periodic structures that form during layer-parallel extension of competent material embedded in less competent material. They can have a wide range of geometries, depending on paleo-rheological conditions. This makes them a powerful tool in interpreting the time–temperature and deformation history of a rock package. Consequently, multiple field and modeling studies have described their geometries as well as explored the boundary conditions for their formation. Inspired by previous findings in modeling and field studies, we test the hypothesis that boudin end member geometries, such as pinch-and-swell, domino, torn, and shear band boudins, can be realized with purely brittle–elastic behavior of the boudinaged layer embedded in a viscous matrix. For this purpose, we designed a parametric Discrete Element Modeling study in which different failure modes in the brittle material are achieved by varying the layer thickness, material cohesion and the layer parallel confining stress. We show that the different boudin geometry is a first order result of the failure mode, fracture mechanics in the brittle layer and the associated post failure behavior. Our models confirm previous findings that block rotation of boudins may be associated with coaxial deformation. Our models indicate a failure mode transition exits between torn and drawn boudins. These results may help us better understand the evolution of boudins and thus help interpret natural examples such as the boudin trains in Naxos, Greece.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"197 ","pages":"Article 105427"},"PeriodicalIF":2.6,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891877","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}

{"title":"Lesser Himalayan thrusting followed by out-of-sequence channel flow in the Greater Himalayan Sequence, north-western Garhwal Himalaya, India: evidence from integrated structural and microtectonic studies","authors":"Subham Bose,&nbsp;Aranya Sen,&nbsp;Vikas Adlakha","doi":"10.1016/j.jsg.2025.105447","DOIUrl":"10.1016/j.jsg.2025.105447","url":null,"abstract":"<div><div>In continent-continent collision zones, the mechanically weak, hot middle crust plays a significant role in the accommodation of convergence between the colliding plates. Thus, multiple tectonothermal episodes are preserved in the middle crust represented in general, by the metamorphic core of collisional orogens like the Himalaya. The present study demonstrates that the Greater Himalayan Sequence (GHS) evolved by mid-crustal channel flow that is out-of sequence with respect to the penetrative fabric forming event in the Paleoproterozoic Lesser Himalayan Sequence (LH) occurring SSW of the GHS, northwestern Garhwal Himalaya, India. Structural and microtectonic studies reveal three phases of deformation at varying thermal regimes across the Himalayan Metamorphic Core (HMC) that constitutes the GHS, the Main Central Thrust (MCT) and the Paleoproterozoic LH, south of the MCT. Out-of-sequence deformation in the LH-GHS package is revealed by the prevalence of the earlier D1 related structures in the Paleoproterozoic LH, and their gradual transposition and reorientation parallel to the late D2 ductile thrusts preserved in the hinterland part (GHS). Crystallographic preferred orientation studies suggest that the GHS extruded as a mid-crustal channel evinced by reversal in the asymmetry of mid-crustal flow across the GHS. SSW-ward extrusion of the GHS as a mid-crustal channel involved a significant pure-shear component (41–66 %) of deformation in transport-parallel section. Fluid infiltration along the MCT was pre-to syn-kinematic with respect to its localized thrust-sense reactivation.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"197 ","pages":"Article 105447"},"PeriodicalIF":2.6,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891876","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}

{"title":"Multi-millennia slip rate relationships between closely spaced across-strike faults: Temporal earthquake clustering of the Skinos and Pisia Faults, Greece, from in situ 36Cl cosmogenic exposure dating","authors":"Sam Mitchell ,&nbsp;Claudia Sgambato ,&nbsp;Jenni Robertson ,&nbsp;Gerald P. Roberts ,&nbsp;Joanna P. Faure Walker ,&nbsp;Zoë Mildon ,&nbsp;Athanassios Ganas ,&nbsp;Ioannis Papanikolaou ,&nbsp;Francesco Iezzi ,&nbsp;Joakim Beck ,&nbsp;Steven A. Binnie ,&nbsp;Tibor Dunai ,&nbsp;Damián A. López ,&nbsp;Georgios Deligiannakis ,&nbsp;Silke Mechernich ,&nbsp;Klaus Reicherter ,&nbsp;Elias J. Rugen","doi":"10.1016/j.jsg.2025.105445","DOIUrl":"10.1016/j.jsg.2025.105445","url":null,"abstract":"<div><div>This study investigates slip behaviour on overlapping, <em>en echelon</em> normal faults by analysing the slip histories of the Skinos and Pisia active normal faults over the past ∼20 kyrs using <em>in situ</em> ³⁶Cl cosmogenic dating. New ³⁶Cl data from the Skinos Fault and published Pisia Fault ³⁶Cl data were modelled, with both sample sites located within an overlap zone and separated by an across-strike distance of 1–2 km. Our analysis reveals fluctuating slip rates, with the two faults alternating between out-of-phase and simultaneous slip. The Pisia Fault exhibited a slip rate of ∼0.5–0.75 mm/yr from ∼20 ka to ∼9.6 ka, increasing to ∼1.25 mm/yr until ∼5.2 ka. It then slowed to ∼0.25 mm/yr or less until ∼2.0 ka, before accelerating again to ∼1.25–1.5 mm/yr to the present day. The Skinos Fault maintained a low slip rate of ∼0.25 mm/yr or less from ∼20 ka to ∼6.4 ka, before accelerating to ∼2.0–3.0 mm/yr, persisting to ∼1.0 ka or possibly the present-day. Comparing their slip histories, the faults show periods of simultaneous slip between ∼6.4 ka to ∼5.2 ka and ∼2.0 ka to ∼1.0–0.0 ka, and out-of-phase slip occurred between ∼9.6 ka and ∼6.4 ka, and from ∼5.2 ka to ∼2.0 ka. Out-of-phase behaviour on faults across strike has now been observed on faults spaced across-strike at distances of 1–2 km, 10–20 km, and ∼100 km, raising the question of why it occurs. Possible mechanism(s), including rheological fluctuations within fault/shear-zone structures linked between the brittle upper crust and viscous lower crust and stress interactions, are discussed to explain the out-of-phase and simultaneous slip behaviour.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"198 ","pages":"Article 105445"},"PeriodicalIF":2.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904537","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}

{"title":"Quartz microstructures and crystallographic preferred orientation analysis across the Himalayan metamorphic core reveal exhumation through changing taper angle and strain partitioning along discreet fault zones","authors":"Aranya Sen ,&nbsp;Swarnendu Roy ,&nbsp;Daeyeong Kim ,&nbsp;Koushik Sen","doi":"10.1016/j.jsg.2025.105446","DOIUrl":"10.1016/j.jsg.2025.105446","url":null,"abstract":"<div><div>The Himalayan metamorphic core in the Bhagirathi Valley of North India comprises three major tectonic zones: the Main Central Thrust zone (MCTz) that separates the Paleoproterozoic Lesser Himalayan Crystalline rocks from the Proterozoic to Cambro-Ordovician Greater Himalayan Sequence; the High Himalayan Discontinuity (HHD) that separates the lower inverted metamorphic sequence from the upper anatectic part of the GHS; and the Jhala Normal Fault (JNF) that marks the northernmost boundary of this metamorphic core. Quartz microstructural analyses across this metamorphic core indicate that dynamic recrystallization at lower temperatures overprinted the high-temperature deformation features, also evident from dominant prism&lt;a&gt; slip in quartz. Strength of quartz crystallographic preferred orientation (CPO) is also highest at these locations. Vorticity analysis suggests simple shear partitioning in the JNF and MCTz, with pure shear in other parts. It is concluded that the exhumation of the Himalayan metamorphic core was facilitated by simple shear along the JNF and MCTz, with thrust propagation south of MCTz compensating for changes in the taper angle of the Himalayan wedge due to activity along the JNF.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"197 ","pages":"Article 105446"},"PeriodicalIF":2.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143882867","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}

{"title":"Deformation and recrystallization mechanisms in glacier salt: Evolution of microstructures inferred from EBSD and microstructural analyses (Kuh-e-Namak diapir (Dashti, Iran))","authors":"Julia Schmitz ,&nbsp;Prokop Závada ,&nbsp;Janos L. Urai ,&nbsp;Karel Schulmann","doi":"10.1016/j.jsg.2025.105441","DOIUrl":"10.1016/j.jsg.2025.105441","url":null,"abstract":"<div><div>This study presents a detailed microstructural analysis of salt samples collected from the exposed mountain glacier in Iran, the Kuh-e-Namak (Dashti). Our goal is to pinpoint the different deformation mechanisms leading to grain size reduction and, how these, together with the influx of rainwater and development of porosity, affect the creep of the polycrystalline halite. We investigated 17 gamma-irradiated thin sections by transmitted and reflected light microscopy, quantitative grain and subgrain statistics, and crystallographic-preferred orientation (CPO) mapping using Electron Back Scattered Diffraction (EBSD). The microstructural evidence suggests a combination of solution-precipitation accompanied by grain-boundary sliding and dynamic recrystallization. The grain size decreases by subgrain rotation recrystallization, microcracking, and grain boundary migration by three different mechanisms: 1) grain boundary bulging into grains, 2) nucleation of new grains and, 3) segmentation of porphyroclasts by planar domains of dynamic recrystallization. The mean grain size ranges from 118 to 508 μm and subgrain sizes from 14 to 99 μm from which differential stresses between 1.9 and 10.2 MPa were calculated. Inferred strain rates for the glacier are in the order of magnitude of 10⁻¹⁰-10⁻⁸ s⁻¹. The increasing shape-preferred orientation of halite grains from the crestal domal part of the diapir towards the frontal parts of extrusive glaciers is interpreted as a result of dominant solution-precipitation creep and salt flow. Rainwater influx rendering this important deformation mechanism switch is attributed to the development of porosity along microcracks and grain boundaries.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"198 ","pages":"Article 105441"},"PeriodicalIF":2.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904538","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}