Journal of Structural Geology最新文献

{"title":"Interplay of positive structural inversion and salt tectonics: The case study of the central algerian margin, Western Mediterranean","authors":"Gaia Travan ,&nbsp;Virginie Gaullier ,&nbsp;Jacques Déverchère ,&nbsp;Bruno C. Vendeville","doi":"10.1016/j.jsg.2024.105133","DOIUrl":"10.1016/j.jsg.2024.105133","url":null,"abstract":"<div><p>Convergence between African and European plates generates compressional strain, primarily concentrated along the northern African margin. This is testified on the Algerian margin by numerous earthquakes (e.g. Bougrine et al., 2019) and by the presence of active folds and thrusts. Multi-channel seismic reflection profiles from the MARADJA I survey reveal north-verging thrusts rooted below the Messinian units, and the geometries of the Messinian salt structures. This study examines the characteristics of salt tectonics offshore Algiers and Dellys, focusing on the effect of the positive structural inversion of the former passive margin on geometries, timing, and mechanisms of salt deformation. The interpretation of seismic reflection and multi-beam bathymetric data of the MARADJA I survey, along with its comparison with analogue models, allowed us to reconstruct the salt tectonics processes on the margin and to identify the predominant role of a plateau uplift on salt deformation. Early and ubiquitous salt deformation by downbuilding was followed by a major phase of plateau uplift (end of Messinian Crisis), leading to westward gravity gliding and a slowdown of the salt deformation above the plateau. Km-tall salt structures were developed and thick minibasins deposited. Salt tectonics is nowadays active only where the relationship between salt and overburden thickness is favorable.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0191814124000853/pdfft?md5=06bf586f0749ea5e27f804771d78b945&pid=1-s2.0-S0191814124000853-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140760764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mylonite, cataclasite, and gouge: Reconstruction of mechanical heterogeneity along a low-angle normal fault: Death valley, USA","authors":"B.M. Lutz ,&nbsp;G.J. Axen","doi":"10.1016/j.jsg.2024.105132","DOIUrl":"https://doi.org/10.1016/j.jsg.2024.105132","url":null,"abstract":"<div><p>The spectrum of slip behavior in crustal faults generates various rock types that can inform the mechanics of earthquake genesis. However, a single fault exposure may contain evidence of slip at various depths and temperatures due to progressive fault rock formation and overprinting during exhumation. Here, we unravel the spatiotemporal evolution of mechanical transitions along the Boundary Canyon detachment, a low-angle normal fault northeast of Death Valley, USA. Field, microstructural, and geochemical characterizations of fault rocks are compared to existing laboratory experiments and combined with a thermo-kinematic model of fault evolution. Together, these constrain the depths of mechanical transitions along the fault and reveal the evolution of earthquake nucleation zone thickness. Fault exposures from different initial paleodepths passed through the mechanical transitions during footwall exhumation, resulting in overprinting of mylonite by cataclasite and ubiquitous late formation of foliated, illite-rich gouge within the uppermost crust. We present evidence of coseismic low-angle normal fault slip (e.g., injection veins of cataclasite, laminar and grain-inertial fluidization). Coseismic slip likely nucleated at strength contrasts within the fault zone (i.e., contacts between quartzite breccia and calc-mylonite; quartz ribbons and mylonite matrix; breccia and clay gouge) at ≈ 5–9.5 km depth. Observations including mutually overprinting cataclasite/ultramylonite and exposures of pulverized gouge support that dynamic rupture propagated down-dip through the brittle-ductile transition zone (≈10–11 km depth) and up-dip through velocity-strengthening fault patches (≈0–5 km depth). Rapid fault exhumation increased the geotherm, leading to upward advection of the brittle-ductile transition and shallowing/thinning of the earthquake nucleation zone. This process may explain the rarity of large magnitude earthquakes on low-angle normal faults.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140638784","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":"Initiation and development of tectonic stylolite – Vein system in micritic limestone (Les Matelles, France)","authors":"Grégory Ballas ,&nbsp;Suzanne Raynaud ,&nbsp;Michel Lopez ,&nbsp;Emilien Oliot ,&nbsp;Jean-Pierre Sizun ,&nbsp;Jacinthe Caillaud ,&nbsp;Fabrice Barou ,&nbsp;Benoit Ildefonse","doi":"10.1016/j.jsg.2024.105130","DOIUrl":"10.1016/j.jsg.2024.105130","url":null,"abstract":"<div><p>In this study, we describe the characteristics of tectonic stylolites and related veins affecting a low-porosity micritic limestone (Jurassic carbonates, Les Matelles, South of France) in order to unravel the conditions of initiation and interaction between pressure-solution and fracturing in such rock. Field description, various petrographic and microstructural investigations (cathodoluminescence, <em>SEM</em> imaging, <em>EBSD</em> analysis), and petrophysical/geochemical analyses (<em>Hg</em> porosimetry, <em>XRD, EPMA</em>) are used. We document that pressure-solution initiates at micropores and propagates along calcite grain contacts, connecting surrounding stylolite micro-segments, and progressively concentrates insoluble material such as clays and siliceous particles. The dissolved material is evacuated to the veins where the newly-formed porous space is progressively filled by calcite cement. These deformation processes are strictly restricted to the stylolitic interface and veins, as no modification of porosity or grain deformation is detected in the neighboring host rock. This is due to the low-permeability of the surrounding host rock impeding the evacuation of dissolved material and fluids through interstitial porosity around the pressure-solution zone, leading to overpressure and veins formation. The water release and microporosity caused by diagenesis of the clay fraction (smectite-illite transformation) are discussed as key diagenetic processes instigating the conditions of pressure-solution initiation, then tectonic stylolite formation in low-porosity limestones.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140617004","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":"Sand, salt, and models: The legacy of Bruno Vendeville","authors":"Mark G. Rowan ,&nbsp;Oriol Ferrer ,&nbsp;Fabien Graveleau ,&nbsp;Virginie Gaullier ,&nbsp;Hemin Koyi ,&nbsp;Sandra Borderie ,&nbsp;Marwa Boussarsar ,&nbsp;G. Ian Alsop","doi":"10.1016/j.jsg.2024.105131","DOIUrl":"10.1016/j.jsg.2024.105131","url":null,"abstract":"<div><p>Bruno Vendeville (1961–2022) was the foremost practitioner of analog modeling applied to the field of salt tectonics, with his work providing and promoting significant advances in our understanding of this field over more than three decades. Bruno and his collaborators contributed major works in: the mechanics of salt-related deformation; the key processes of extensional, contractional, loading-induced, and strike-slip salt tectonics; the drivers and patterns of gravity-driven, linked systems of salt-detached deformation; and the structural style and evolution of specific salt basins. In this Special Issue devoted to his legacy, we offer a series of papers that build on his foundational work and honor his critical role in advancing the theory and application of salt tectonics.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140763129","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":"An improved incremental shortening calculation method of the shear fault-bend fold","authors":"Weiheng Zhang ,&nbsp;Jie Chen ,&nbsp;Tao Li ,&nbsp;Yuan Yao ,&nbsp;Qi Liu ,&nbsp;Ning Di","doi":"10.1016/j.jsg.2024.105129","DOIUrl":"https://doi.org/10.1016/j.jsg.2024.105129","url":null,"abstract":"<div><p>Shear fault-bend folds, a common feature of fault bend folds in foreland fold-and-thrust belts, originate in the early deformation stage. Building upon Suppe's geometric model of 'shear fault-bend folding,' we present refined calculation formulas for total shortening, incremental shortening, and the shear coefficient specific to these folds, as well as ideas to verify model parameters. The practicality and versatility of our refined approach are confirmed through case studies of the Pakuashan anticline in Taiwan and the Tugulu anticline in North Tian Shan. This improved incremental shortening calculation formula, conserves the bed length and eliminates errors of the widely used shortening calculation formula, is crucial for understanding deformation processes and assessing seismic risks shear fault bend folding. To obtain more precise incremental shortening calculations, it should further refine the geometric and kinematic models of shear fault bend folding in the future.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140649967","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":"Fracture ellipticity as a measure of chemical reaction-controlled fracture growth","authors":"Natchanan Doungkaew ,&nbsp;Peter Eichhubl","doi":"10.1016/j.jsg.2024.105127","DOIUrl":"https://doi.org/10.1016/j.jsg.2024.105127","url":null,"abstract":"<div><p>Natural fractures are generally viewed as elliptical in shape, consistent with elastic fracture mechanics. To quantify deviations of fracture shape from theoretically predicted elliptical opening distributions and to evaluate processes leading to non-elliptical fracture shapes, we measured aperture profiles of quartz-cemented opening-mode fractures in low-grade metamorphic sandstone. Ellipticity was quantified by the Lamé n-value, with measured n-values deviating significantly from n = 2 for elliptical shapes, ranging from 0.7 for tapered fractures to 3.2 for blunted fractures.</p><p>While some deviation from n = 2 can be explained by mechanical interaction with nearby fractures and layer boundaries, we explain the generally observed large variation in n values with competing processes between chemically assisted subcritical fracture propagation, leading to preferred fracture length growth and tapered tips for non-recoverable inelastic fracture opening by solution-precipitation creep, and preferred aperture growth and tip blunting by locally enhanced solution-precipitation creep in the fracture tip region. Using geometric models, we show that preferred length growth with non-recoverable fracture opening strain can lead to tapered fractures with n = 1; Preferred aperture growth and opening increments with Lamé n = 3 result in overall blunted fracture shapes with n &gt; 2. We propose that fracture ellipticity provides a measure of chemically reactive fracture growth processes in geological systems.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140606844","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":"3D variation of shortened salt walls from the Moroccan Atlas: Influence of salt inclusions and suprasalt sedimentary wedges","authors":"Antonio Teixell ,&nbsp;Michael R. Hudec ,&nbsp;María-Luisa Arboleya ,&nbsp;Naiara Fernandez","doi":"10.1016/j.jsg.2024.105125","DOIUrl":"https://doi.org/10.1016/j.jsg.2024.105125","url":null,"abstract":"<div><p>We present a field study of salt ridges and minibasins of the Moroccan High Atlas near Rich that shows the along- and across-strike variability of such structures. Salt walls evolved from halokinesis during Jurassic rifting, to shortening during Cenozoic orogeny. Salt wall segments exhibit variable degrees of welding due primarily to the local presence of intrasalt inclusions (basalt and gabbro) rather than orientation with respect to the shortening or position along the ridge. Flanking Jurassic minibasins may be upright and symmetric or tilted; tilting may have started during halokinesis but was largely acquired during shortening. Minibasins tilt away from welded diapiric segments towards inclusion-rich segments, indicating differential diapir rise. The structure of the central parts of the salt walls differs from the lateral terminations. While the central parts are relatively simple with aperture or welding governed by the inclusions, many salt walls end buried by suprasalt sedimentary wedges. These perched wedges were not arched upward during diapir squeezing but were unexpectedly folded into synclines. The folding was formed by the flanking minibasin tilting in one limb and by inhomogeneous diapir rise and lateral salt escape in the other, thus defining a new modality of roof and shoulder folding above salt diapirs.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140555140","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":"Late quaternary faulted landforms and recent activity of the eastern segment of the Nanbei River–Boli Fault","authors":"Wei Xu ,&nbsp;Ji Wang ,&nbsp;Jinhui Yin","doi":"10.1016/j.jsg.2024.105128","DOIUrl":"https://doi.org/10.1016/j.jsg.2024.105128","url":null,"abstract":"<div><p>The Nanbei River–Boli Fault is one of the largest NW-trending faults in Northeast China. However, limited data on the style and timing of recent earthquake activity on this fault greatly restrict the accuracy of seismic risk assessment. Here, we provide evidence of late Pleistocene to Holocene activity of the eastern segment of this fault for the first time. Specifically, the eastern segment of the Nanbei River–Boli Fault has experienced multiple earthquakes since the late Quaternary. Trench excavations indicate a recent strong earthquake at 7.28–2.11 ka, with approximately 1 m of co-seismic vertical displacement and preliminary estimates of the minimum vertical slip rates of 0.07–0.12 mm/a. According to a comprehensive analysis, we estimate that the eastern segment of the Nanbei River–Boli Fault can generate strong earthquakes of magnitude 7.0. This research provides important information for seismic risk assessments and seismic zoning, which can help seismic hazard assessment and mitigate their effects in Northeast China.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140631543","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 relationship between kinematics and fault geometry for surface coseismic ruptures on across-strike faults: New observations of slip vectors and displacements along the Pisia and Skinos faults from the 1981 Eastern Gulf of Corinth, Greece earthquakes","authors":"Sam Mitchell ,&nbsp;Gerald P. Roberts ,&nbsp;Joanna P. Faure Walker ,&nbsp;Francesco Iezzi ,&nbsp;Claudia Sgambato ,&nbsp;Jennifer Robertson ,&nbsp;Zoë K. Mildon ,&nbsp;Athanassios Ganas ,&nbsp;Ioannis D. Papanikolaou ,&nbsp;Elias J. Rugen","doi":"10.1016/j.jsg.2024.105117","DOIUrl":"https://doi.org/10.1016/j.jsg.2024.105117","url":null,"abstract":"<div><p>The relationships between kinematics and fault geometry for the coseismic ruptures from the 24th and February 25, 1981 earthquake sequence in the eastern Gulf of Corinth (Ms 6.7 and 6.4) are analysed. The two earthquakes ruptured faults located across strike rather than along strike as typifies other earthquake sequences. In detail, surface ruptures formed on the sub-parallel Pisia and Skinos Faults, with an 8 km along-strike overlap zone, separated across strike by &lt; 2 km. The largest coseismic offsets occurred in the overlap zone. The 41-year-old ruptures are still well preserved as bedrock fault plane lichen-free stripes and colluvial ruptures, allowing detailed structural mapping at 213 rupture localities. A comparison between our measurements and Jackson et al. (1982) showed no overall consistent signal of post-seismic slip as some of our measurements were greater and some smaller than those recorded in 1981. The ruptures produced a single maximum asymmetric profile (Pisia: maximum throw of 223 cm) and a double maxima profile (Skinos: maximum throw of 109 cm and 130 cm). The shapes of the profiles differed in previous earthquakes on these faults, as evidenced by an older lichen-free stripe, implying non-characteristic earthquakes. Summing the two overlapping throw profiles across-strike reveals a single maximum symmetric bell-like profile. Using the above observations on coseismic offsets, kinematic information, and the geometry of faults, a rupture scenario has been proposed in terms of fault bends and corrugation orientations which suggests that parts of each fault may have ruptured in each earthquake.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0191814124000695/pdfft?md5=9af1e9dd000f6f8a7d73d2cf9e02dd32&pid=1-s2.0-S0191814124000695-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140546013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strain partitioning dominated growth of strike-slip fault: Insight from the Tan-Lu fault in Eastern China","authors":"Rong Chu ,&nbsp;Dan-Ping Yan ,&nbsp;Liang Qiu ,&nbsp;De-Shuang Chang ,&nbsp;Qi Wang ,&nbsp;Xian-Qiang Song ,&nbsp;Chao Wang","doi":"10.1016/j.jsg.2024.105126","DOIUrl":"https://doi.org/10.1016/j.jsg.2024.105126","url":null,"abstract":"<div><p>The dynamic variations of the strain field and associated tectonic deformation during fault evolution can provide useful insights into the fault growth mechanisms. As one of the longest strike-slip fault system in the world, the ∼3000-km length Tan–Lu fault zone (TLFZ) in eastern China, is ideal for studying the mechanisms of fault propagation and linkage. This study investigated the Cenozoic Liaodong Bay subbasin, which hosts main structures of four faults in the central TLFZ, using structural analysis and strain calculations based on abundant seismic data. Our new results reveal three stages of fault growth (D₁, D₂, and D₃) during the Cenozoic. Strain partitioning occurred during D₁, with non-coaxial deformation within the high-strain regions leading to the growth of individual fault segments. D₂ involved the redistribution of strain partitioning, with localized strain overlapping along fault tips to produce both left- and right-stepping fault sets. The locally increased simple-shear component favored the development of right-stepping fault arrays. Fault linkage appears to be achieved in two ways: 1) left-stepping, dextral faults were linked by folds dominated by pure shear along overlapping fault tips, and 2) fault segments were linked via fractures developed in simple-shear-dominated right-stepping overlap zones. D₃ was characterized by the continued accumulation of simple shear, which resulted in fault linkage through fractures and formed continuous faults with high strain. Therefore, we propose a tectonic model in which strain partitioning results in linkage of segmented faults along fault tips. This model takes into account the spatial and temporal variations in fault geometry and strain type during the growth of the strike-slip fault, provides theoretical support for the structural patterns observed in natural faults worldwide.</p></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140539822","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}