Journal of Structural Geology最新文献

{"title":"Analysis of middle to deep-depth strike-slip faults in the southern Ordos Basin, China: A case study of the Xunyi area","authors":"Yunwen Guan ,&nbsp;Qichao Wang ,&nbsp;Renhai Pu ,&nbsp;Sujie Yan ,&nbsp;Shuo Chen ,&nbsp;Siyu Su","doi":"10.1016/j.jsg.2025.105509","DOIUrl":"10.1016/j.jsg.2025.105509","url":null,"abstract":"<div><div>High-resolution 3D seismic reflection data and coherence attribute analysis reveal a complex network of small-scale strike-slip faults (0.2–20 km in length) within the Xunyi area of the southern Ordos Basin at burial depths of 0.4–3.5 km. These structures exhibit a multi-phase evolution history characterized by distinct deformation patterns across different stratigraphic intervals.</div><div>Structural analysis identifies four distinct tectonic episodes: (1) initial development of NE and NW-trending fault systems during the Caledonian movement (Cambrian-Ordovician), (2) limited reactivation during the Hercynian event (Carboniferous-Permian), (3) formation of NWW to E-W-trending sinistral strike-slip faults during the Indosinian event (Early-Middle Triassic), and (4) right-lateral transpressional reactivation during the Yanshanian event (Late Jurassic-Early Cretaceous).</div><div>Mohr space analysis reveals that the angular relationship between fault orientation and regional stress fields fundamentally controls three distinct patterns of structural inheritance: (1) The XY1 fault maintains continuous activity through all tectonic phases due to its optimal N72-86°E orientation relative to successive stress fields; (2) The XY2-4 faults exhibit early termination after the Caledonian period despite their basement-cutting nature, attributed to their unfavorable orientation under subsequent stress regimes; (3) The Mesozoic faults (W1-4) initiated independently during the Indosinian period with N64-86°E strikes, displaying 33–44° counterclockwise rotation from pre-existing Paleozoic structures.</div><div>Detailed fault growth analysis reveals an early stress interaction mechanism where approaching fault segments develop secondary faults and displacement patterns before geometric overlap occurs. This observation challenges the traditional four-stage fault linkage model that assumes significant interaction only after substantial fault overlap, suggesting more complex stress field interactions during early fault development.</div><div>This integrated study provides critical insights into intraplate deformation processes within cratonic basins, demonstrating how the orientation of pre-existing structures relative to evolving regional stress fields fundamentally controls fault reactivation patterns in multi-phase tectonic settings.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105509"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655257","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":"A modern scientific methodology for structural geology","authors":"David D. Pollard ,&nbsp;Stephen R. Pollard","doi":"10.1016/j.jsg.2025.105494","DOIUrl":"10.1016/j.jsg.2025.105494","url":null,"abstract":"<div><div>Papers on methodology by G. K. Gilbert from the late 19th century have attracted geologists' attention into the 21st century. Gilbert's memoir on the Henry Mountains includes two mechanical models based on physical theory found in W. J. M. Rankine's Manual of Applied Mechanics. Rankine's analysis of the stratification of hydrostatic fluids of different densities corresponds closely to Gilbert's Model #1 applied to magmatic intrusions. However, the sedimentary rocks of the Henry Mountains are not fluids, and though Model #1 failed Gilbert's tests, he did not reject it. Model #2 replaced the flexure over the laccolith with an encircling fault, enabling Gilbert to analyze laccolith formation using balanced parallel forces. His tests of Model #2 were successful and led to a physical relationship between the diameter and depth of laccoliths. We modernize Gilbert's methodology using the equations of motion for the material continuum provided by A. -L. Cauchy's First and Second Laws. These apply to rocks that deform and fracture as brittle solids, and those that deform plastically as ductile solids, as well as to magmas that flow as viscous fluids. This egalitarian functionality means that: 1) most geological structures are candidates for models based on Cauchy's Laws; 2) geologists must specify the constitutive properties of the deforming rocks or magmas; and 3) these models satisfy the conservation laws of mass and momentum. This modern methodology provides structural geologists with an on-going and self-correcting process of scientific investigation as new field and laboratory data accumulate and new hypotheses are tested.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105494"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517020","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 magnetic fabrics in isoclinal folds of the Variscan Pyrenees","authors":"B. Oliva-Urcia ,&nbsp;T. Román-Berdiel ,&nbsp;P. Clariana ,&nbsp;R. Soto ,&nbsp;E. Izquierdo-Llavall ,&nbsp;A. Casas-Sainz","doi":"10.1016/j.jsg.2025.105495","DOIUrl":"10.1016/j.jsg.2025.105495","url":null,"abstract":"<div><div>Magnetic fabrics are used as strain markers since they reflect the orientation-distribution of grains in a rock. In this work we analyzed, from the point of view of anisotropy of magnetic susceptibility (at low-temperature and room temperature), Devonian (29 sites) and Ordovician-Silurian (3 sites) sedimentary rocks in the Pyrenean Axial Zone, totalling 611 samples. The main target is to determine the strain in relation to the Variscan (polyphased) and Alpine orogenies in limestones and shales. The magnetic information also derives from thermomagnetic curves, acquisition of the isothermal remanent magnetization (IRM) and coercivity of the remanence analyses, together with hysteresis loops and stepwise thermal demagnetization of induced IRM in 3 axes techniques. The analyses of magnetic properties were complemented with optical microscopy observations and calcimetries. In two of the sample areas (Sen and Llisat valleys), the minimum axes of the magnetic susceptibility ellipsoid (k_min axes) are mostly perpendicular to bedding whereas in the other two (Zinqueta valley and near Posets peak area), a more developed tectonic fabric is found: the k_min axes are not completely perpendicular to bedding, and the magnetic susceptibility ellipsoid relates to the foliation plane. Different minerals carry a concordant magnetic fabric with pyrrhotite, magnetite (ferromagnetic <em>s.l.)</em> and phyllosilicates (paramagnetic), and little influence of calcite grains (diamagnetic). The magnetic fabric is interpreted to form at the early stages of the Variscan deformation, prior to the dextral transpression synchronous with granite emplacement that characterizes the late stages of the Variscan Orogeny. However, contact metamorphism and associated fluid circulation can enhance or obliterate the primary magnetic fabric.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105495"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517531","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":"Switching from contractional to extensional tectonics along the Alpine Front: structural and metamorphic evidence from the Balagne area (northern Corsica, France)","authors":"Maria Di Rosa ,&nbsp;Edoardo Sanità ,&nbsp;Alessandro Malasoma ,&nbsp;Luca Pandolfi ,&nbsp;Michele Marroni","doi":"10.1016/j.jsg.2025.105471","DOIUrl":"10.1016/j.jsg.2025.105471","url":null,"abstract":"<div><div>In the Corsica Island (France), the tectonic boundary along which the units of Alpine Corsica overlap the Hercynian Corsica represents a first-order structure which has not been investigated in depth yet. In this paper, the reconstruction of the Alpine Corsica Front in the Balagne area through the characterization of the deformation history and the associated peak metamorphism for the units of Alpine Corsica and for the Hercynian Corsica is provided. The collected data indicate that a gap in the peak metamorphism between the less metamorphic units located at the top of the unit pile, and those located at lower structural level which registered low-blueschist facies conditions exists. Also, a detailed structural analysis of the shear zones along the Alpine Corsica Front is supplied. The studied N-S trending, E-dipping shear zones documented at the western rim of the Balagne area are characterized by deformation history indicating a top-to-E sense of shear that overprint a former top-to-W kinematics. These findings indicate that the Alpine Corsica Front was affected by extensional tectonics after the shortening, which developed during the top-to-W thrusting of the Alpine Corsica onto the Hercynian Corsica. Framing our results in the regional tectonic setting, we suggest that the extensional tectonics documented in the Balagne area developed during the Oligocene-Early Miocene, i.e., during the transition from the latest stages of orogenic exhumation within the Alpine belt to the post-orogenic rifting stage in the Liguro-Provençal and Tyrrhenian Basins.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105471"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195700","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":"Inter-granular damage in experimentally deformed rock-salt investigated by X-ray micro-tomography: confining pressure and brine effects","authors":"Nina Du ,&nbsp;Michel Bornert ,&nbsp;Alexandre Dimanov ,&nbsp;Patrick Aimedieu ,&nbsp;Laura Blanco-Martín ,&nbsp;Jubier A. Jiménez-Camargo","doi":"10.1016/j.jsg.2025.105488","DOIUrl":"10.1016/j.jsg.2025.105488","url":null,"abstract":"<div><div>We have investigated the mechanical behaviour of synthetic rock-salt during compression tests using <em>in situ</em> X-ray micro computed tomography (XR-μCT). Samples were deformed under controlled strain rate in an X-ray semi-transparent triaxial cell adapted to X-ray tomography.</div><div>We were interested in the development of micro damage in relation to the stress state and the presence or absence of brine. For that purpose, we produced by powder compaction in œdometric cells two types of materials with different amounts of water. One is considered “laboratory dry” and the other is considered “water saturated”. Both materials exhibit similar mean grain size (c.a. 200 μm). Both types of samples were deformed at uniaxial and triaxial conditions (15 MPa confining pressure), at room temperature and constant displacement rate (1 μm/s).</div><div>The results show that the dominant damage mechanisms correspond to the progressive development of diffuse inter-granular micro-cracking. This can be explained by the strong anisotropy in the crystal plasticity of NaCl, which results in local plastic strain incompatibilities between neighboring grains in the polycrystalline rock-salt. Conversely, the development of micro-crack damage is strongly reduced by both confining pressure and presence of brine. Natural Leine rock salt samples bearing inter-crystalline brine and tested under similar conditions show similar trends as regards inter-granular micro-damage. We suggest that the development of inter-granular micro-cracking is suppressed or retarded in the presence of brine thanks to dissolution-precipitation processes, which in addition to the well-known healing effect may also reduce the local plastic strain incompatibilities.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105488"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144492006","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":"Partitioning of strain rates and stresses between a thin shear zone and its walls under transpression or transtension","authors":"Pierre-Yves F. Robin ,&nbsp;Alexander R. Cruden","doi":"10.1016/j.jsg.2025.105484","DOIUrl":"10.1016/j.jsg.2025.105484","url":null,"abstract":"<div><div>Within a mid-crustal domain deforming in transpression or transtension, thin zones may exhibit higher strain than their immediately adjacent walls. The lower transpressive strain of the host may sometimes not be recognized and these thin bands might thus be interpreted as simple shear zones. However, their kinematic indicators should reflect the transpressional or transtensional strain imposed by the less deformed host. In order to explore the contrasting strain between such a zone and its walls, we analyse a simple model of a narrow low-viscosity oblique transcurrent shear zone held coherently within a broader, higher-viscosity host rock. The model uses strain rate as a proxy for strain.</div><div>We evaluate the contrasts in strain rate intensities and in shape parameters between such a shear zone and its walls as functions of viscosity contrast and of convergence angles. We find important differences between transpressional or transtensional shear zones and the more familiar simple shear zones.</div><div>Strain fabrics observed in some crustal scale shear zones and their walls, such as the Archean Larder Lake-Cadillac Deformation Zone (LCDZ) in Ontario and Québec, Canada, which combine transcurrent shear sense indicators and steeply plunging lineations, can indeed be explained by transpression.</div><div>We also examine the contrast in stresses between the shear zone and its walls. We find that, in transpression, buoyant fluids that might be generated in the deep crust, near the base of a deformation zone such as the LCDZ, should in fact move through the wall rock rather than within that high-deformation zone. This has implications for the location of mineral deposits traditionally associated with such deformation zones.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105484"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263483","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":"Reconstructing the framework of the Paleo-Pacific Plate: A synthetic review","authors":"Sanzhong Li ,&nbsp;Yong-Fei Zheng ,&nbsp;Yanhui Suo","doi":"10.1016/j.jsg.2025.105505","DOIUrl":"10.1016/j.jsg.2025.105505","url":null,"abstract":"<div><div>The Paleo-Pacific Ocean Basin would evolve from the Panthalassa and develop ancient plates such as Paleo-Pacific, Farallon and Phoenix. Multilines of geological and geophysical evidence indicate that a new-born plate, named the Pacific Plate, would initially develop at 190 Ma among these three plates in the Paleo-Pacific Ocean Basin, but it did not take shape until 55 Ma when the Paleo-Pacific Plate would finally disappear on the East Asian continental margin. Therefore, the Paleo-Pacific Plate and the Pacific Plate would co-evolve or co-exist from 190 Ma to 55 Ma in the Paleo-Pacific Ocean Basin. The ocean basin after the complete disappearance of the Paleo-Pacific Plate at 55 Ma is the Pacific Ocean Basin as presently seen. Geologically, the Pacific Ocean Basin is marked by the initial formation of the plate configuration on the current Pacific seafloor in the Mesozoic. Therefore, when did the Paleo-Pacific Plate begin in the Paleo-Pacific Ocean Basin? When was the Paleo-Pacific Plate subducted beneath the East Asian continental margin? How would its appearance and disappearance are spatiotemporally recorded in geology? What are its geological effects during its subduction beneath the East Asian continental margin? Although there are numerous studies dealing with the formation and evolution of the Paleo-Pacific Plate, the results have brought many big debates on its composition and structure. Some scholars refer to the Paleo-Pacific Plate differently, leading to some great difficulties in academic exchanges. There are three mainstream viewpoints: the Paleo-Pacific Plate is either the Kula Plate, or the Izanagi Plate, or a collage of many plates. Although the Paleo-Pacific Plate existed as a mysterious on Earth in the Mesozoic, a large number of geological observations indicate that its evolution is closely related to the tectonic evolution of the East Asian continental margin in this period. Therefore, it is necessary to recognize and reconstruct the configuration of the Paleo-Pacific Plate and its tectonic effects on the East Asian continental margin. This paper attempts to systematically summarize the previous observations and interpretations of the Paleo-Pacific Plate, to distinguish between the concepts of the Kula Plate, the Izanagi Plate and the Paleo-Pacific Plate in different study stages, and to systematically explore various differences in plate reconstruction since the proposal of the Paleo-Pacific Plate. Based on the current progresses on plate tectonics, this paper also summarizes the relevant geological records of the Paleo-Pacific Plate, including the continental margin accretion of oceanic plateaus, island arc basalt-like magmatic rocks and terrane-collage accretion. The time of its subduction initiation, geometric evolution and spatial range changes are explored, and its tectonic evolutionary history is reconstructed. Finally, remaining problems are presented for the future research.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105505"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670571","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":"A long history of ductile and brittle deformation of Eastern Pyrenees fault zones: coupling 40Ar/39Ar geochronology, chlorite geothermometry and structural observation","authors":"Gaétan Milesi ,&nbsp;Philippe Münch ,&nbsp;Delphine Charpentier ,&nbsp;Arthur Iemmolo ,&nbsp;Aoutmane Bouaoudi ,&nbsp;Andreï Lecomte ,&nbsp;Virginie Moutarlier ,&nbsp;Renaud Gley ,&nbsp;Michael Bonno ,&nbsp;Patrick Monié","doi":"10.1016/j.jsg.2025.105465","DOIUrl":"10.1016/j.jsg.2025.105465","url":null,"abstract":"<div><div>In orogenic settings, fault networks accommodate crustal deformation during the evolution of mountain ranges. Fault zones exhibit multiphase ductile and brittle activity, complicating their interpretation. Dating deformation in orogenic basement remains a challenge. In this study, we conducted structural and microstructural observations, coupled with ⁴⁰Ar/³⁹Ar dating on encapsulated mineral fractions and chlorite thermometry, on major fault zones in the Eastern Pyrenees. To overcome the presence of K-feldspar within fault gouge, a major issue for fault gouge argon dating, we present a method to estimate the contribution of two mixed K-rich phases from ⁴⁰Ar/³⁹Ar step heating. This method provides limit or maximum age for the deformation recorded by fault gouges in which illite polytypes are mixed with K-feldspar. Our results reveal a ductile-to-brittle transition between 40 and 35 Ma (Priabonian-Bartonian), characterized by 2<em>M</em>1 muscovite and evidence of strike-slip movement along the Py NE-SW fault and NW-SE secondary faults. The Py fault gouge contains muscovite formed at temperatures exceeding 200–250 °C. In the Têt NE-SW fault gouge, the coexistence of 2<em>M</em>1 and 1<em>M</em> illite polytypes suggests late-stage crystallization of 1<em>M</em> illite at 22.1 ± 1.4 Ma, at temperatures between 100 and 150 °C, as determined by chlorite thermometry. These findings confirm significant normal faulting activity on the Têt fault during the Oligo-Miocene, consistent with published low-temperature thermochronology data indicating early exhumation of the Canigou massif relative to the Carança massif, facilitated by normal displacement along the Py fault, and a later exhumation of both massifs in relation to the Têt normal fault activity.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105465"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212020","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":"Integration of deformed objects into a composite object analogous to the strain ellipse: a novel graphic method of Rf/ϕ strain analysis","authors":"Yehua Shan","doi":"10.1016/j.jsg.2025.105470","DOIUrl":"10.1016/j.jsg.2025.105470","url":null,"abstract":"<div><div>The composite object of post-strain elliptical objects is defined as having a radial length that is the square root of the normalized sum of the squared radial lengths of the objects. It proves analogous to the strain ellipse and makes <em>R</em>_<em>f</em><em>/ϕ</em> strain analysis simple. The finite strain is estimated from the overall shape of the composite object. The discrepancy between the composite object and the estimated strain ellipse is used to appraise the assumption of the uniformly distributed major axes of pre-strain objects. Two strain methods, direct calculation and numerical estimation, are developed to determine the strain from the composite object. Synthetic and natural datasets are used to validate the methods.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105470"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255196","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":"Sequence, duration, rate of deformation and paleostress evolution during fold development: Insights from fractures, calcite twins and U-Pb calcite geochronology in the Mirabeau anticline (SE France)","authors":"Anies Zeboudj ,&nbsp;Olivier Lacombe ,&nbsp;Nicolas E. Beaudoin ,&nbsp;Jean-Paul Callot ,&nbsp;Juliette Lamarche ,&nbsp;Abel Guihou ,&nbsp;Guilhem Hoareau","doi":"10.1016/j.jsg.2025.105460","DOIUrl":"10.1016/j.jsg.2025.105460","url":null,"abstract":"<div><div>The timing and duration of folding events have traditionally been constrained by the dating of syn-tectonic layers that record fold growth and limb rotation. However, recent advances demonstrate that absolute U-Pb geochronology on well-characterized distributed mesoscale structures such as fractures and stylolites allows the reconstruction of a detailed deformation timeline spanning the entire folding event even when growth strata are absent. In this study, we integrate structural analysis with calcite twin paleopiezometry, inversion of fault slip data, and U-Pb dating of syn-tectonic calcite mineralizations from faults, veins and stylolite-related jogs to refine the classical fold-fracture model and provide a more comprehensive view and precise timing of brittle deformation and stress evolution during folding using the example of the Mirabeau anticline (Provence, SE France). The onset of layer-parallel shortening (LPS) has been precisely constrained for the first time using absolute U-Pb dating of a calcite-filled jog associated with a bedding-parallel stylolite (BPS) and the earliest striated reverse faults associated with Pyrenean shortening. The brittle deformation associated with the folding event of the Mirabeau anticline is recorded continuously between ∼50 Ma and ∼37 Ma, with layer parallel shortening (LPS) lasting ∼5 My, fold growth lasting ∼3 My, and late-stage fold tightening (LSFT) lasting ∼5 My. Combining our shortening estimate derived from and balanced cross-section with absolute ages of fold growth, we estimate a Pyrenean shortening rate of approximately 0.6 mm/yr at Mirabeau. Our results further place important new time constraints on the sequence of structural development through the Provence fold-and-thrust belt, and support a forelandward propagation of Pyrenean deformation across Provence.</div><div>The integration of fracture sequence analysis, calcite twin inversion and striated fault inversion provides insights into the tectonic evolution of the Mirabeau area: (1) pre-Pyrenean alternating NNE-SSW and WNW-ESE extension between ∼112 and ∼90 Ma, likely related to the Durance uplift event (2) Eocene Pyrenean-Provençal shortening dominated by a N-S to NE-SW horizontal σ₁ under alternating compressional and strike-slip stress regimes, (3) Oligocene E-W extension associated with the West European rifting event, and (4) a minor compressional stress regime with NW-SE to NNW-SSE oriented σ1 attributed to Miocene Alpine shortening.</div></div>","PeriodicalId":50035,"journal":{"name":"Journal of Structural Geology","volume":"199 ","pages":"Article 105460"},"PeriodicalIF":2.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144288663","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}