Tectonophysics最新文献

{"title":"Evidence of active faulting obtained by the waveform inversion of the seismic moment tensor and InSAR analysis in Northeastern Mexico: El Corcovado seismic sequence of May to August 2023","authors":"Juan C. Montalvo-Arrieta ,&nbsp;Jorge A. Salinas-Jasso ,&nbsp;Víctor H. Espíndola ,&nbsp;Luis G. Ramos-Zuñiga ,&nbsp;Juan A. Ramírez-Fernández","doi":"10.1016/j.tecto.2025.230668","DOIUrl":"10.1016/j.tecto.2025.230668","url":null,"abstract":"<div><div>The first recorded moderate-intensity mainshock and largest aftershock in the boundary between the Basin and Range and Sierra Madre Oriental provinces are presented. This seismological evidence demonstrates the presence of active faulting in northeastern Mexico. We estimated seismic source parameters and surface deformation related to a low-moderate seismic sequence that occurred from May 11 to August 2, 2023 (3.4 ≤ <em>M</em>_d ≤ 5) in the limits of the San Luis Potosí, Nuevo León and Tamaulipas states through waveform inversion of the seismic moment tensor and InSAR analysis. The event of May 16, 2023 (<em>M</em>_d 5.0, <em>M</em>_w 4.92) is the biggest earthquake instrumentally recorded in this region. The mainshock and the largest aftershock (June 5, 2023; <em>M</em>_d 4.9, <em>M</em>_w 4.86) earthquakes were well-recorded over 100–330 km by broadband stations installed in central and northeastern Mexico. Here, it is suggested that both earthquakes were associated with the rupture of El Corcovado normal fault. We estimated a rupture area of approximately 11 km² with an average displacement of 7 cm. Fault plane solutions of the mainshock were strike 358°, dip 39°, rake −90°, and Mo 2.685e+16 Nm. El Corcovado fault is associated with a set of normal faults NNW-SSE trending located along the boundary between the Basin and Range and the Sierra Madre Oriental provinces. Such considerations lead to a review of the neotectonic setting of northeastern Mexico and the associated seismic hazard assessment.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"902 ","pages":"Article 230668"},"PeriodicalIF":2.7,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bathymetric and structural insights into the Islas Marías Archipelago, Mexico, and surrounding areas","authors":"Felipe de Jesús Escalona-Alcázar ,&nbsp;Francisco Javier Núñez-Cornú ,&nbsp;Diana Núñez ,&nbsp;Diego Córdoba-Barba","doi":"10.1016/j.tecto.2025.230669","DOIUrl":"10.1016/j.tecto.2025.230669","url":null,"abstract":"<div><div>The Islas Marías Archipelago is located south of the Gulf of California. This study presents a structural geologic analysis of María Madre Island, coupled with a detailed bathymetric survey of the surrounding area. Our goal is to delineate the deformation geometry and identify new morphostructural features in the region. Bedding tilting coincided with normal faulting of the lower member of the Ojo de Buey sequence, likely at the end of the Pliocene or the beginning of the Pleistocene, associated with the early stage of the Gulf of California rifting. Seismic reflection profiles from previous studies indicate that the West Ranges are within a thinned continental crust, structurally controlled by the María, Magdalena, and South Magdalena faults. Furthermore, a detailed bathymetric survey and orthoimages from the islands revealed structural lineaments in both oceanic and continental crust. In the continental crust, these lineaments have a preferred orientation between 050° to 090°, similar to the faulting trend on María Madre Island. However, they are oblique to those in the oceanic crust and mainland Mexico. We propose that María Madre Island may have undergone a 50° clockwise rotation. If we apply a counterclockwise rotation of this magnitude to the faults and lineaments in the continental crust of the archipelago and the region west of it, their preferred orientation becomes parallel to the Tamayo Fracture Zone in the oceanic crust, the San Blas fault within the continental shield and, the Tepic-Zacolaco rift extending eastward into mainland Mexico. This suggests that rotation affected the continental crust, either west of Puerto Vallarta, in the archipelago, or the West Ranges, while the oceanic crust remained relatively unaffected. We propose the term “Islas Marías Block” to designate a fragment of continental crust encompassing the archipelago and the West Ranges, which share a common deformation style.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"901 ","pages":"Article 230669"},"PeriodicalIF":2.7,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Local seismicity along the Olenek Sector of the Lena-Anabar suture, SW Laptev Sea Rift System – Rift-related or reactivation of the former passive margin of the Siberian Craton?","authors":"A. Plötz ,&nbsp;A. Krylov ,&nbsp;W.H. Geissler ,&nbsp;S. Shibaev ,&nbsp;F. Krüger ,&nbsp;C. Haberland ,&nbsp;B. Baranov ,&nbsp;R. Tuktarov ,&nbsp;N. Tsukanov ,&nbsp;M. Novikov","doi":"10.1016/j.tecto.2025.230676","DOIUrl":"10.1016/j.tecto.2025.230676","url":null,"abstract":"<div><div>The Laptev Sea region in Northeast Siberia is one out of very few examples for possible initiation of continental breakup. In the North seismicity concentrates along the Gakkel Ridge separating the oceanic parts of the North American and Eurasian plates. Earthquake epicenters are more diffuse on the Laptev Sea Shelf and further inland, where in 1927 two M6.7 earthquakes occurred just 200 km to the South of the seaport of Tiksi. Suspicious hypocenter depths of up to 80 km have been reported from short temporary deployments near the coast. Following reconnaissance investigations in 2015, we installed one detection array near Tiksi in summer 2016 as a joint Russian-German initiative. In addition, a temporary network of 12 stations were deployed by ship along major river branches within the Lena Delta to the west of Tiksi.</div><div>Here we report on seismicity from the first observation period from late July 2016 till May 2017. The analysis of more than 500 local and regional earthquakes show, that focal depths extend to about 30 km within the lower crust, but we could not find evidence for earthquakes in the uppermost mantle beneath our seismological network. Local magnitudes mL range from −0.9 to 3.7 during our observation period. Furthermore, a local 1D seismic velocity model is derived from the data that was used for the location of the earthquakes. Several earthquake swarm-like sequences or earthquake bursts occurred throughout the observation period. Focal mechanisms of the small-magnitude earthquakes are not conclusive, but hint to a partly transpressional regime in the study area.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"901 ","pages":"Article 230676"},"PeriodicalIF":2.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of horizontal stress ratio on frictional stability of fault under true triaxial stress conditions","authors":"Zhiming Liang ,&nbsp;Zhenyu Zhang ,&nbsp;Haoran Dou ,&nbsp;Shengpeng Hao","doi":"10.1016/j.tecto.2025.230678","DOIUrl":"10.1016/j.tecto.2025.230678","url":null,"abstract":"<div><div>To understand the fault friction stability and seismic mechanisms under in-situ stress conditions of the Earth's crust, the rectangular prismatic rock sample with a sawcut fault inclined at an angle of 29° to the axis is introduced to withstand the three stress components of true triaxial stress conditions (vertical stress <em>σ</em>_v, horizontal stress <em>σ</em>_h, and stress parallel to the strike of the fault plane <em>σ</em>_p). Velocity-stepping experiments are performed on the sawcut faults to investigate fault frictional behavior and slip stability under different <em>σ</em>_h/<em>σ</em>_p ratios and stress <em>σ</em>_p within the rate-and-state framework. Results indicate that increasing <em>σ</em>_h/<em>σ</em>_p ratios decrease the frictional velocity-dependent parameter (<em>a</em>-<em>b</em>), exhibiting a transition from velocity-strengthening to velocity-weakening behaviors. Shallow grooves develop along the fault surface and act as stress barriers at the low <em>σ</em>_h/<em>σ</em>_p ratio. With increasing <em>σ</em>_h/<em>σ</em>_p ratios, the fault surface gradually converges to uniform smoothness due to asperity abrasion, suggesting that the weakening effect of increasing <em>σ</em>_h/<em>σ</em>_p ratios on fault stability is related to stress redistribution. The enhanced fault critical stiffness (<em>K</em>_c) with increasing <em>σ</em>_h/<em>σ</em>_p ratios promotes fault instability nucleation. Our results reveal that true triaxial in-situ stress states in seismogenic zones exert significant control on frictional behavior and fault stability.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"901 ","pages":"Article 230678"},"PeriodicalIF":2.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping a seismic barrier across the Shumagin Gap from satellite goce derivatives direct and inverse modeling","authors":"Orlando Álvarez ,&nbsp;Silvana Spagnotto ,&nbsp;Silvina Nacif ,&nbsp;Mario Gimenez ,&nbsp;Andrés Folguera","doi":"10.1016/j.tecto.2025.230657","DOIUrl":"10.1016/j.tecto.2025.230657","url":null,"abstract":"<div><div>The earthquake potential of the segment known as the Shumagin gap, located along the southwestern Alaska convergent margin, has been debated for over 40 years. This portion of the megathrust has not experienced a historically great earthquake with a magnitude (Mw) greater than Mw = 8.0, or at least none has been recorded in the instrumental era, exhibiting a moderate to low slip deficit. On 22 July 2020, an Mw = 7.8 thrust-fault earthquake ruptured a deeper portion of the megathrust along the eastern edge of the Shumagin Gap. Aftershocks following this event, including an Mw = 7.6 strike-slip earthquake on 19 October 2020, delineated an approximate north-south fault zone. Later, on 29 July 2021, an Mw = 8.2 thrust-fault earthquake ruptured the Semidi segment to the East. In this work, we examined the coseismic behavior of the Shumagin gap and adjacent Semidi segment along the Alaska margin from direct and inverse models obtained from satellite-derived gravity data. The distribution of the vertical gravity gradient shows a saddle point topography along the Shumagin Gap where the aftershocks of the July 2020 Mw = 7.8 earthquake concentrated in a nest. The gravity disturbance and the inverse model of mass anomalies also show an along-strike segmentation. Anomalous mass inferred along the Shumagin Gap, is consistent with the seismicity, focal mechanisms, and recently published works, suggesting that this segment hosts a seismic barrier (along-strike) that limits earthquakes with magnitudes Mw &gt; 8.0. On the other hand, an across-strike (along-dip) segmentation is inferred from Tzz, which is consistent with vertical motion models. Comparison of the interplate coupling and <em>b-values</em> distribution to the vertical gravity gradient, allowed mapping main asperities in the region suggesting that the area to the west of the Shumagin gap could host a great megathrust earthquake in the future.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"900 ","pages":"Article 230657"},"PeriodicalIF":2.7,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of uncertainty propagation within compaction-based exhumation studies using Bayesian inference","authors":"Patrick Makuluni ,&nbsp;Juerg Hauser ,&nbsp;Stuart Clark","doi":"10.1016/j.tecto.2025.230660","DOIUrl":"10.1016/j.tecto.2025.230660","url":null,"abstract":"<div><div>Exhumation plays a crucial role in shaping the evolution and distribution of resource systems in sedimentary basins, affecting mineral and energy resource exploration. Accurate exhumation estimates, derived primarily from empirical equations based on compaction and thermal datasets, are essential but are often compromised by data errors and unquantified uncertainties in model parameters. For instance, model parameters are usually assumed not to be affected by uncertainties despite varying within measurable ranges. Uncertainties from such variation can propagate and compromise the accuracy of exhumation estimates.</div><div>This study introduces a novel and refined approach to exhumation estimation using Markov Chain Monte Carlo (MCMC) methods to quantify and address uncertainties in data and model parameters. Using this approach, we developed a workflow for quantifying exhumation magnitudes and their associated uncertainties and applied it to sonic log datasets from the Canning and Bonaparte Basins. The impact of uncertainty propagation on exhumation results was assessed by examining four scenarios: assuming no uncertainty in the model or data, considering data noise without model uncertainty, considering model uncertainty without data noise, and considering model uncertainties and data noise together.</div><div>Our study yielded robust exhumation estimates in the Canning and Bonaparte Basins. Comparison with previous studies shows similarities and differences in exhumation estimates for multiple episodes, with discrepancies potentially arising from variations in exhumation models, data quality and coverage. Uncertainty propagation analysis reveals that considering data-related and model uncertainties together produces variable distributions of exhumation estimates with wider uncertainty ranges. Overall, data quality and coverage proved more critical for the accuracy and precision of exhumation estimates than model refinement. Our models can be integrated into basin evolution studies, help refine fluid migration models, and improve understanding of sedimentation and ore preservation to optimise resource exploration in sedimentary basins.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"900 ","pages":"Article 230660"},"PeriodicalIF":2.7,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-dependent stress changes associated with the 1999 İzmit (MW = 7.5) and Düzce (MW = 7.2) earthquakes in NW Türkiye: Implications for seismicity changes and earthquake hazard","authors":"Murat Utkucu ,&nbsp;Hatice Durmuş ,&nbsp;Fatih Uzunca ,&nbsp;Süleyman Sami Nalbant","doi":"10.1016/j.tecto.2025.230656","DOIUrl":"10.1016/j.tecto.2025.230656","url":null,"abstract":"<div><div>In this study, we calculated coseismic and time-dependent viscoelastic (VE) postseismic Coulomb stress changes of the 1999 İzmit (<em>M</em>_W = 7.5) and Düzce (<em>M</em>_W = 7.2) earthquakes along the North Anatolian Fault Zone (NAFZ). We assessed these changes in relation to the seismicity surrounding <em>M</em>_W ≥ 5.0 earthquakes and the selected faults and locations. Excluding the 2009–2011–2012 Simav and 2020 Kırkağaç earthquake sequences, the calculated stress changes coincided with the observed seismicity changes. Our findings suggest that stress changes from nearby <em>M</em>_W &gt; 6.0 earthquakes provided approximately 1.9 bars of stress load for the 2009 Simav earthquake, yet only a minor stress increase (about 0.07 bars) for the 2020 Kırkağaç earthquake compared to the stress decreases (about −0.3 and − 0.18 bars, respectively) caused by the 1999 mainshocks. Nevertheless, geological and seismological evidence from published studies indicates that magma-driven stress changes may have influenced occurrence of the Kırkağaç earthquake. For the 2006 Gemlik earthquake, the coseismic stress shadow was neutralized by VE postseismic stress load at its hypocenter in 2006, suggesting it may be a long-standing off-fault aftershock of the 1999 İzmit earthquake. We also identified a seismicity shutdown due to stress shadowing along the Bursa and İnegöl faults, whereas significant stress loads caused high seismic activity along the Elmalık and Bakacak faults, as well as at the Akyazı and Gölyaka locations. Additionally, stress change calculations along the Middle Strand of the NAFZ reveal that VE postseismic stresses have been generally rising since 1999, effectively reducing negative or augmenting positive coseismically imposed stress changes. Given the last ruptures of the Middle Strand in 1419 and 1556, this fault strand may be capable of producing two earthquakes in the order of <em>M</em>_W = 7.2–7.3.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"900 ","pages":"Article 230656"},"PeriodicalIF":2.7,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tomographic evidence for segmentation of the Main Himalayan Thrust in the Uttarakhand Himalaya","authors":"Jyotima Kanaujia ,&nbsp;M. Ravi Kumar ,&nbsp;Naresh Bandari ,&nbsp;R. Vijayaraghavan","doi":"10.1016/j.tecto.2025.230655","DOIUrl":"10.1016/j.tecto.2025.230655","url":null,"abstract":"<div><div>Imaging the Main Himalayan Thrust (MHT) along and across the strike of the Himalaya is critical to understand seismogenesis and earthquake hazard. This study investigates the 3D P and S velocity structure of the Garhwal-Kumaon Himalaya (GKH) using travel times of 846 local events recorded at 54 broadband stations. Depth sections of the velocity anomalies capture the flat-ramp-flat structure of the MHT. The MHT is expressed as a low-velocity layer, possibly due to dehydration of sediments. Also, the geometry of the MHT seems distinctly different in the Garhwal and Kumaon segments. It is steeper with a narrow width in the former and gentler with a larger width in the latter. The width of the MHT is ∼60 km in Garhwal and ∼ 85 km in Kumaon. However, if the whole MHT is assumed as a locked zone, its width from the Main Frontal Thrust to the 3.5 km elevation contour in the Higher Himalaya is ∼115 in the former and ∼ 130 km in the latter. The MHT in Garhwal has a 30 km wide shallow ramp (∼2°) in the upper flat attached to a ∼ 30° steeply dipping 10 km wide ramp, which merges with a lower flat at a depth of ∼20 km beneath the Main Central Thrust(MCT). Such a flat-ramp-flat geometry is not evident in Kumaon, with the MHT remaining flat. Also, the subsurface structures and earthquake depths beneath the MCT differ in these segments, with a varying thickness of the low-velocity layer. Relocation of earthquakes using the 3D tomographic model reveals a dominant (85–90 %) occurrence in the upper crust. The seismicity is found to straddle within a narrow zone of 30–50 km around the MCT. While the seismicity belt is mostly to the south of MCT in Kumaon, it is along and north of it in Garhwal. Deeper seismicity in Garhwal sub-Himalaya seems associated with the deep-seated Delhi Haridwar Ridge (DHR) transverse to the strike of Himalaya.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"900 ","pages":"Article 230655"},"PeriodicalIF":2.7,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of seismogenesis beneath the Tripura Fold Belt and its adjoining areas of Northeast India","authors":"Ajay Pratap Singh ,&nbsp;Om Prakash Singh ,&nbsp;Ram Bichar Singh Yadav ,&nbsp;Om Prakash Mishra","doi":"10.1016/j.tecto.2025.230658","DOIUrl":"10.1016/j.tecto.2025.230658","url":null,"abstract":"<div><div>In this study, a comprehensive analysis comprising the relocation of ∼400 well-located earthquakes (M ≤ 4.9) recorded during 2013–2015 and 19-moment tensor solutions has been made. The earthquakes were recorded by 20 seismographic stations belonging to the Geological Survey of India (GSI) and National Centre for Seismology (NCS) networks. Then, the results are corroborated with the geophysical and geological investigations for the areas that need better characterization of the seismotectonics beneath the Tripura Fold Belt (TFB) and its adjoining areas in Northeast (NE) India. The sparse seismicity distribution associated with TFB shows north-south trending anticlinal ridges and synclinal valleys. These structures decrease progressively towards the south and are confined to depths between 40 and 60 km. The mixed mode of faulting at various depths indicates significant structural heterogeneity beneath TFB that dictates the earthquake strength. We conspicuously relocated earthquakes in a cluster along the Sylhet fault (SF) with a dominant northeast striking, suggesting the presence of differential structural heterogeneities with variable strengths of earthquakes located at varying depths, which in turn indicates that the seismogenesis beneath the Sylhet fault is associated with thrust mode of faulting with distinct slip component during the processes of the rupture initiation. Moment tensor solution of the area inferred two main directions: NNE –SSW and WNW – ESE, suggesting two compressive forces acting in the study area. The NNE-SSW compressional stress is dominant in this zone. This study provides deep insights into the two different structural entities, TFB and SF of NE India, that can have the potential to contribute significantly for assessing the earthquake risk potential of the region.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"901 ","pages":"Article 230658"},"PeriodicalIF":2.7,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tectonic evolution of the Atlantic rift, central sector offshore Uruguay","authors":"Marmisolle Josefina ,&nbsp;Morales Ethel ,&nbsp;Rossello Eduardo ,&nbsp;Soto Matías ,&nbsp;Javier Hernández-Molina","doi":"10.1016/j.tecto.2025.230654","DOIUrl":"10.1016/j.tecto.2025.230654","url":null,"abstract":"<div><div>The Uruguayan Continental Margin (UCM) is considered one of the most promising frontier areas for hydrocarbon exploration in the South Atlantic. The UCM central sector, corresponding to the transitional region between the Punta del Este and Pelotas basins and where the Rio de la Plata Transfer System (RPTS) is located, exhibits outstanding characteristics such as interruption of the seaward dipping reflectors (SDRs), dislocation of magnetic and gravity anomalies and depocenters, and hyper-thinning of the continental crust. Owing to these characteristics, this sector is a key area for understanding the evolution of the margin during the Atlantic opening and evaluating the real potential of the UCM to contain hydrocarbon accumulations. This study demonstrates the results of a new subsurface mapping method using 2D and 3D seismic data in the central sector of the UCM. Structural interpretations have led to the definition of i) a NW-oriented hyperextended region located where the SDRs are interrupted, characterized by a shallow Moho (˂3 km); ii) a set of NW-SE oriented transtensional faults, some of which reach the Moho, which has delineated a series of discrete grabens; and iii) a Barremian-Aptian depocenter with a rhomboidal geometry, exhibiting the greatest thickness over the hyperextended crust region. The central sector of the UCM concentrates on the extensional processes associated with the breakup of Western Gondwana, which controlled the initial phase of the Atlantic opening in this region. The sinistral transcurrent nature of the RPTS plays a crucial role in generating the transtensional stress field in an extensive regional context. This process reactivates basement-inherited structures with a general NW-SE orientation, leading to the formation of subsidence areas. The proposed new tectonic model will contribute to the knowledge of the hydrocarbon potential of the UCM.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"899 ","pages":"Article 230654"},"PeriodicalIF":2.7,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}