Tectonics最新文献_第3页

Transient Aseismic Vertical Deformation Across the Steeply-Dipping Pisia-Skinos Normal Fault (Gulf of Corinth, Greece) 穿越陡倾皮西亚-斯基诺斯正断层的瞬态地震垂直变形（希腊科林斯湾）

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-08-02 DOI: 10.1029/2024tc008276

Zoë K. Mildon, Manuel Diercks, Gerald P. Roberts, Joanna P. Faure Walker, Athanassios Ganas, Ioannis Papanikolaou, Vassilis Sakas, Jenni Robertson, Claudia Sgambato, Sam Mitchell

{"title":"Transient Aseismic Vertical Deformation Across the Steeply-Dipping Pisia-Skinos Normal Fault (Gulf of Corinth, Greece)","authors":"Zoë K. Mildon, Manuel Diercks, Gerald P. Roberts, Joanna P. Faure Walker, Athanassios Ganas, Ioannis Papanikolaou, Vassilis Sakas, Jenni Robertson, Claudia Sgambato, Sam Mitchell","doi":"10.1029/2024tc008276","DOIUrl":"https://doi.org/10.1029/2024tc008276","url":null,"abstract":"Geodetically-derived deformation rates are sometimes used to infer seismic hazard, implicitly assuming that short-term (annual-decadal) deformation is representative of longer-term deformation. This is despite geological observations indicating that deformation/slip rates are variable over a range of timescales. Using geodetic data from 2016 to 2021, we observe an up to 7-fold increase in vertical deformation rate in mid-2019 across the Pisia-Skinos normal fault in Greece. We hypothesize that this deformation is aseismic as there is no temporally correlated increase in the earthquake activity (M > 1). We explore four possible physical mechanisms, and our preferred hypothesis is that the transient deformation is caused by centimeter-scale slip in the upper 5 km of the Pisia fault zone. This is the first observation of shallow tectonic (i.e., not related to human activities) aseismic deformation on a normal fault globally. Our results suggest that continental normal faults can exhibit variable deformation over shorter timescales than previously observed, and thus care should be taken when utilizing geodetic rates to quantify seismic hazard.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"75 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Magmatism and Polyphase Deformation in the Middle Jurassic Arc of Central Chile: Implications for the Tectonic Development of the Early Andean Margin 智利中部中侏罗世弧的岩浆活动和多相变形：早期安第斯边缘构造发展的影响

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-31 DOI: 10.1029/2023tc008241

John S. Singleton, Gloria Arancibia, Diego Morata, Ignacia Pérez De La Maza

{"title":"Magmatism and Polyphase Deformation in the Middle Jurassic Arc of Central Chile: Implications for the Tectonic Development of the Early Andean Margin","authors":"John S. Singleton, Gloria Arancibia, Diego Morata, Ignacia Pérez De La Maza","doi":"10.1029/2023tc008241","DOIUrl":"https://doi.org/10.1029/2023tc008241","url":null,"abstract":"The ∼173–164 Ma Papudo-Quintero plutonic complex near 32.5°S in central Chile records three deformation events that provide insight into the tectonic development of the early Andean margin. The first event (D1) includes: (a) high-temperature (>600°C), coaxial-dominated strain along NE- to N-striking subvertical shear zones; (b) widespread emplacement of granitic dikes that dip gently to steeply NE; and (c) development of narrow (<10 cm thick) strike-slip and oblique-reverse shear zones. These D1 structures record NW-SE to WNW-ESE transpressional shortening with a component of sinistral shear parallel to the N-S trending magmatic arc. Zircon and apatite U-Pb dates and cross-cutting relations constrain most D1 deformation to ∼166–164 Ma. The second event (D2) occurred during postmagmatic cooling in the Late Jurassic and was characterized by development of pervasive E-W-striking veins with alteration halos and minor strike-slip and normal faults that record N-S extension in a transtensional regime. Structures associated with the last deformation event (D3) include Late Jurassic to Early Cretaceous mafic dikes, veins, and conjugate strike-slip faults that record NW-SE to N-S shortening in a strike-slip regime. D1 deformation is consistent with studies from other areas that document NW-SE shortening ± sinistral transpression along the arc throughout the Jurassic, suggesting this deformation was regional in scale and driven by oblique subduction convergence. Deformation associated with oblique convergence was localized within the active magmatic arc, which was an important process in the early Andean orogeny. As the arc migrated eastward, D2 and D3 structures formed in a low-stress regime in an arc margin or forearc setting.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"217 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

3D Structure of Low-Angle Normal Faults and Tectono-Sedimentary Processes of Nascent Continental Core-Complexes in the SE South China Sea 中国南海东南部低角度正断层的三维结构与新生大陆核心复合体的构造沉积过程

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-29 DOI: 10.1029/2023tc008218

E. Legeay, G. Mohn, J. C. Ringenbach, W. Vetel, F. Sapin

{"title":"3D Structure of Low-Angle Normal Faults and Tectono-Sedimentary Processes of Nascent Continental Core-Complexes in the SE South China Sea","authors":"E. Legeay, G. Mohn, J. C. Ringenbach, W. Vetel, F. Sapin","doi":"10.1029/2023tc008218","DOIUrl":"https://doi.org/10.1029/2023tc008218","url":null,"abstract":"This contribution explores the formation and evolution of hyper-extended basins, associated with the early stage of core complex formation, controlled by low-angle normal faults active at <30°. Based on a high-resolution industrial 3D seismic reflection survey along the southern margin of the South China Sea (SCS) (Dangerous Grounds), we mapped and analyzed the 3D geometry of low-angle normal fault systems and the related stratigraphy. Two main hyper-extended basins were documented, filled by up to 6 km of sediments including pre- to post-rift sequences. The observed normal faults on depth migrated seismic sections show an average dip angle of <30° and appear planar, characterized by continuous reflections with no clear steepening at depth and sole-out on distinct decollement levels. Detailed fault surface mapping reveals the occurrence of km-scale corrugations together with large wavelength undulation. The formation of these hyper-extended basins is associated with polyphased syn-rift infill during the development of the low-angle normal faults. The first syn-rift sequence appears as chaotic and discontinuous packages that has been dismembered and fragmented during the activity of low-angle normal faults. The second syn-rift package shows unexpected sedimentary wedges developing successively toward the footwall and the hangingwall. This geometry results from the interplay between the main low-angle normal fault and antithetic faults defining a so-called extensional fishtail. The deep structure of these basins shows nascent domes with limited evidence of magmatism. Eventually, these basins likely capture the earliest stage of core complex development in the proximal margin of the southern SCS.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"2 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Post-Collisional Reorganisation of the Eastern Alps in 4D – Crust and Mantle Structure 东阿尔卑斯山碰撞后的四维重组--地壳和地幔结构

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-28 DOI: 10.1029/2024tc008374

Peter J. McPhee, Mark R. Handy

{"title":"Post-Collisional Reorganisation of the Eastern Alps in 4D – Crust and Mantle Structure","authors":"Peter J. McPhee, Mark R. Handy","doi":"10.1029/2024tc008374","DOIUrl":"https://doi.org/10.1029/2024tc008374","url":null,"abstract":"The Eastern Alps were affected by a profound post-collisional tectonic reorganisation in Neogene time, featuring indentation by the Adriatic upper plate, rapid uplift and filling of the eastern Molasse Basin, exhumation and eastward orogen-parallel transport of Paleogene metamorphic units in the orogenic core, and a shift from northward thrust propagation in the European plate to southward propagation in the Adriatic plate. We test the idea that these events were triggered by slab detachment by reconstructing the indentation process. This involves sequentially restoring N-S and E-W cross-sections of the orogenic wedge and correcting for out-of-section orogen-parallel transport with a map-view reconstruction. We propose two phases of indentation: Initially (23 and 14 Ma), the whole Adriatic crust acted as an indenter. Its northward motion was accommodated by upright folding and orogen-parallel extensional exhumation in the Tauern Window. This phase was followed (14 Ma to Present) by continued orogen-parallel transport of the orogenic wedge into the Pannonian Basin and deformation of the leading edge of the Adriatic indenter, forming the Southern Alps fold-thrust belt. The lower crust of the Southern Alps indented the base of the Venediger Nappes in the Tauern Window, forming a high-velocity (6.8–7.25 km/s) ridge in map view at 30–45 km depth. By correlating the post-23 Ma orogenic evolution with presently imaged European slab segments in P-wave teleseismic tomography, we discern two possible Neogene slab removal events: One from 23 to 19 Ma triggering tectonic reorganisation of the Eastern Alps and its foreland basin, and potentially a second event after 14 Ma.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"78 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geodynamic and Climatic Forcing on Late-Cenozoic Exhumation of the Southern Patagonian Andes (Fitz Roy and Torres del Paine massifs) 南巴塔哥尼亚安第斯山脉（菲茨-罗伊和托雷斯-德尔-潘恩山丘）晚新生代侵蚀的地球动力和气候作用力

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-23 DOI: 10.1029/2023tc007914

Veleda A. P. Muller, Christian Sue, Pierre G. Valla, Pietro Sternai, Thibaud Simon-Labric, Cécile Gautheron, Kurt M. Cuffey, Djordje Grujic, Matthias Bernet, Joseph Martinod, Matias C. Ghiglione, Peter Reiners, Chelsea Willett, David Shuster, Frédéric Herman, Lukas Baumgartner, Jean Braun

{"title":"Geodynamic and Climatic Forcing on Late-Cenozoic Exhumation of the Southern Patagonian Andes (Fitz Roy and Torres del Paine massifs)","authors":"Veleda A. P. Muller, Christian Sue, Pierre G. Valla, Pietro Sternai, Thibaud Simon-Labric, Cécile Gautheron, Kurt M. Cuffey, Djordje Grujic, Matthias Bernet, Joseph Martinod, Matias C. Ghiglione, Peter Reiners, Chelsea Willett, David Shuster, Frédéric Herman, Lukas Baumgartner, Jean Braun","doi":"10.1029/2023tc007914","DOIUrl":"https://doi.org/10.1029/2023tc007914","url":null,"abstract":"High-relief glacial valleys shape the modern topography of the Southern Patagonian Andes, but their formation remains poorly understood. Two Miocene plutonic complexes in the Andean retroarc, the Fitz Roy (49°S) and Torres del Paine (51°S) massifs, were emplaced between 16.9–16.4 Ma and 12.6–12.4 Ma, respectively. Subduction of oceanic ridge segments initiated ca. 16 Ma at 54°S, leading to northward opening of a slab window with associated mantle upwelling. The onset of major glaciations caused drastic topographic changes since ca. 7 Ma. To constrain the respective contributions of tectonic-mantle dynamics and fluvio-glacial erosion to rock exhumation and landscape evolution, we perform inverse thermal modeling of a new data set of zircon and apatite (U-Th)/He from the two massifs, complemented by apatite 4He/3He data for Torres del Paine. Our results show rapid rock exhumation recorded only in the Fitz Roy massif between 10 and 8 Ma, which we ascribe to local mantle upwelling forcing surface uplift and intensified erosion around 49°S. Both massifs record a pulse of rock exhumation between 7 and 4 Ma, which we interpret as enhanced erosion during the beginning of Patagonian glaciations. After a period of erosional and tectonic quiescence in the Pliocene, increased rock exhumation since 3–2 Ma is interpreted as the result of alpine glacial valley carving promoted by reinforced glacial-interglacial cycles. This study highlights that glacial erosion was the main driver to rock exhumation in the Patagonian retroarc since 7 Ma, but that mantle upwelling might be a driving force to rock exhumation as well.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"19 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Tectonic Structure and Evolution of the Potiguar-Ceará Rifted Margin of Brazil 巴西波蒂瓜尔-卡拉裂谷边缘的构造和演化

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-22 DOI: 10.1029/2023tc008184

Julia C. Fonseca, Cesar R. Ranero, Paola Vannucchi, David Iacopini, Helenice Vital

{"title":"The Tectonic Structure and Evolution of the Potiguar-Ceará Rifted Margin of Brazil","authors":"Julia C. Fonseca, Cesar R. Ranero, Paola Vannucchi, David Iacopini, Helenice Vital","doi":"10.1029/2023tc008184","DOIUrl":"https://doi.org/10.1029/2023tc008184","url":null,"abstract":"The Brazilian Equatorial Margin (BEM) is interpreted as a transform margin, where the last segment opened during Gondwana rifting. However, margin evolution, and break-up age remain unconstrained. We interpret >10k km of crustal-scale seismic images extending along ∼600 km of the margin calibrated with drillholes. We determine the style and timing of tectonics across the rift system. We link changes in crustal-scale structure and age of sediment deposits to interpret variations with the style of extension and intensity of thinning across the BEM. Observations support a rift evolution where deformation is initially distributed forming a shallow basin, subsequently focusses, and later migrates basin-ward forming the deep-water domain. We interpret that tectonic activity started ∼140–136 Ma and stopped earlier in the shallow basin causing minor thinning, than in the deep-water domain with a ∼60 km wide area with 4–8 km thick crust extended in Late Aptian to Early Albian (116–110 Ma). Constraints from seismic and drilling help define an abrupt continent to ocean transition (COT) where continental crust may be abutted by oceanic crust, and breakup occurred at early Albian time. Basin sedimentation from the onset to the Late Aptian is continental, indicating an isolated environment disconnected from Atlantic oceans. During late-most Aptian to Early Albian basin sedimentation changes and indicates a comparatively rapid marine water infill. Rifting of the BEM is not dominated by transcurrent deformation as previously inferred, with strike-slip faulting limited to comparatively small sectors, whereas most of the margin extended by normal faulting deformation.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"8 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural Variation Along the Southern Hikurangi Subduction Zone, Aotearoa New Zealand, From Seismic Reflection and Retro-Deformation Analysis 从地震反射和逆变形分析看新西兰奥特亚罗瓦南 Hikurangi 俯冲带的构造变化

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-17 DOI: 10.1029/2023tc008212

D. E. Stevens, Y. L. C. McNeill, T. J. Henstock, P. M. Barnes, G. Crutchley, N. Bangs, S. Henrys, H. J. A. Van Avendonk

{"title":"Structural Variation Along the Southern Hikurangi Subduction Zone, Aotearoa New Zealand, From Seismic Reflection and Retro-Deformation Analysis","authors":"D. E. Stevens, Y. L. C. McNeill, T. J. Henstock, P. M. Barnes, G. Crutchley, N. Bangs, S. Henrys, H. J. A. Van Avendonk","doi":"10.1029/2023tc008212","DOIUrl":"https://doi.org/10.1029/2023tc008212","url":null,"abstract":"The southern Hikurangi subduction zone exhibits significant along-strike variation in convergence rate and obliquity, sediment thickness and, uniquely, the increasing proximity of southern Hikurangi to, and impingement on, the incoming continental Chatham Rise, an ancient Gondwana accretionary complex. There are corresponding changes in the morphology and structure of the Hikurangi accretionary prism. We combine widely spaced multichannel seismic reflection profiles with high resolution bathymetry and previous interpretations to characterize the structure and the history of the accretionary prism since 2 Ma. The southern Hikurangi margin can be divided into three segments. A northeastern segment (A) characterized by a moderately wide (∼70 km), low taper (∼5°) prism recording uninhibited outward growth in the last ∼1 Myr. Deformation resolvable in seismic reflection data accounts for ∼20 % of plate convergence, comparable with the central Hikurangi margin further North. A central segment (B) characterized by a narrow (∼30 km), moderate taper (∼8°) prism, with earlier (∼2-∼1 Ma) shortening than segment A. Outward prism growth ceased coincidentally with development of major strike-slip faults in the prism interior, reduced margin-normal convergence rate, and the onset of impingement on the incoming Chatham Rise to the south. A southwestern segment (C) marks the approximate southern termination of subduction but widens to ∼50 km due to rapid outward migration of the deformation front via fault reactivation within the now-underthrusting corner of the Chatham Rise. Segment C exhibits minimal shortening as margin-normal subduction velocity decreases and plate motion is increasingly taken up by interior thrusts and strike-slip faults.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"11 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141746370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Slab Tear of Subducted Indian Lithosphere Beneath the Eastern Himalayan Syntaxis Region 东喜马拉雅同轴区下方俯冲印度岩石圈的板块撕裂

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-11 DOI: 10.1029/2024tc008248

Ziqing Li, Bo Zhang, Lei Guo, Zhaoliang Hou, Bernhard Grasemann, Fulong Cai, Houqi Wang

{"title":"Slab Tear of Subducted Indian Lithosphere Beneath the Eastern Himalayan Syntaxis Region","authors":"Ziqing Li, Bo Zhang, Lei Guo, Zhaoliang Hou, Bernhard Grasemann, Fulong Cai, Houqi Wang","doi":"10.1029/2024tc008248","DOIUrl":"https://doi.org/10.1029/2024tc008248","url":null,"abstract":"In the southeastern Tibetan Plateau, region-scale dextral strike-slip shear zones, crucial for India-Asia convergence, were investigated along the Dulongjiang shear zone near the Eastern Himalayan Syntaxis (EHS). Structural, kinematic, and geochronological data from Dulongjiang and Nabang regions in western Yunnan, China, reveal dextral strike-slip shearing between 30 and 15 Ma. Various rocks were affected by moderate-temperature shear deformation (∼450–550°C), inferred from microstructures and quartz CPO patterns, during dextral strike-slip and exhumation of the shear zone. Combined with structures of pre-, syn-, and post-shearing leucogranites, zircon U-Pb dating indicates that the dextral shear along the shear zone began in the Early Oligocene (30–29 Ma) subsequent to the India-Asia collision. Micas in mylonitic granites yield 40Ar/39Ar ages, suggesting that the principal dextral shear deformation occurred approximately between 18 and 15 Ma. The Dulongjiang shear zone is linked to the Parlung, Nabang shear zone, and Sagaing Fault, forming a regional Cenozoic dextral shear system around the EHS. The study, combined with tomographic anomalies beneath the India-Asia collision zone, highlights distinct lithospheric-scale evolution in southeastern and eastern Tibet. Continuous intracontinental strike-slip shearing indicates a tectonic shift from Tibetan extension to block rotation around the EHS. From 30 to 15 Ma, slab tear, accompanied by clockwise rotation and dextral strike-slip shearing, suggests a warmer geodynamic setting influenced by hot mantle flow associated with ongoing subduction of the Indian lithosphere. Oligocene-Miocene dextral strike-slip shearing around the EHS, linking southwards with the Sagaing Fault, may correspond to the rotation necessary for slab to bend, stretch, and eventually tear beneath the region.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"29 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Constraining Displacement Magnitude on Crustal-Scale Extensional Faults Using Thermochronology Combined With Flexural-Kinematic and Thermal-Kinematic Modeling: An Example From the Teton Fault, Wyoming, USA 利用热年代学结合挠曲-线性和热-线性建模对地壳尺度伸展断层的位移幅度进行约束：以美国怀俄明州泰顿断层为例

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-09 DOI: 10.1029/2024tc008308

Autumn L. Helfrich, J. Ryan Thigpen, Victoria M. Buford-Parks, Nadine McQuarrie, Summer J. Brown, Ryan C. Goldsby

{"title":"Constraining Displacement Magnitude on Crustal-Scale Extensional Faults Using Thermochronology Combined With Flexural-Kinematic and Thermal-Kinematic Modeling: An Example From the Teton Fault, Wyoming, USA","authors":"Autumn L. Helfrich, J. Ryan Thigpen, Victoria M. Buford-Parks, Nadine McQuarrie, Summer J. Brown, Ryan C. Goldsby","doi":"10.1029/2024tc008308","DOIUrl":"https://doi.org/10.1029/2024tc008308","url":null,"abstract":"Constraining the geometry and displacement of crustal-scale normal faults has historically been challenging, owing to difficulties with geophysical imaging and inability to identify precise cut-offs at depth. Using a modified workflow previously applied to contractional systems, flexural-kinematic (Move) and thermal-kinematic (Pecube) models are integrated with apatite (U-Th)/He (AHe) and apatite fission track (AFT) data from Teton footwall transects to constrain total Teton fault displacement (Dmax). Models with slip onset at ∼10 Ma and flexure parameters that best match the observed Teton flexural profile require Dmax > 8 km to produce young (<10 Ma) AHe ages observed at low elevation footwall positions in the Tetons. For the same slip onset, models with Dmax of 11–13 km provide the best match to observed AHe data, but displacements ≥16 km are required to produce observed AFT ages (13.6–12.0 Ma) at low elevations. A more complex model with slow slip onset at ∼25 Ma followed by faster slip at ∼10 Ma yields a good match between modeled and observed AHe ages at a Dmax of 13–15 km. However, this model predicts low elevation AFT ages 6–8 Ma older than observed ages, even at Dmax values of 16–17 km. Based on this analysis and integration with previous studies, we propose a unified evolution wherein the Teton fault likely experienced 11–13 km of Miocene-recent displacement, with AFT data likely indicating a pre-to early Miocene cooling history. Importantly, this study highlights the utility of using integrated flexural- and thermal-kinematic models to resolve displacement histories in extensional systems.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"49 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Late Miocene Oroclinal Bending of the Mazatagh Thrust Belt in the Central Tarim Basin and Its Tectonic Implications 塔里木盆地中部马扎塔格隆起带的晚中新世弧形弯曲及其构造影响

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-07 DOI: 10.1029/2023tc008233

Bingshuai Li, Maodu Yan, Heng Peng, Weilin Zhang, Jinbo Zan, Tao Zhang, Xiaomin Fang

{"title":"Late Miocene Oroclinal Bending of the Mazatagh Thrust Belt in the Central Tarim Basin and Its Tectonic Implications","authors":"Bingshuai Li, Maodu Yan, Heng Peng, Weilin Zhang, Jinbo Zan, Tao Zhang, Xiaomin Fang","doi":"10.1029/2023tc008233","DOIUrl":"https://doi.org/10.1029/2023tc008233","url":null,"abstract":"The arcuate Mazatagh thrust belt (MTB) in the central Tarim Basin is one of the key regions for understanding the Cenozoic intracontinental deformation in response to the India–Eurasia collision. However, whether it was formed due to oroclinal bending and its kinematic processes remain unclear. Here, we present a detailed paleomagnetic rotation study at Hongbaishan in the middle MTB to shed new light on the deformation in this region. Positive fold and reversal tests of 50 site means suggest primary magnetizations. The paleomagnetic declinations indicate ∼14.6 ± 8.5° absolute clockwise rotation at Hongbaishan since the late Miocene (∼7.6 Ma). Together with the rotation results calculated from Hongbaishan-1 and Mazatagh magnetostratigraphic data sets in the southeastern MTB, these results reveal an increasing magnitude of clockwise rotation along the belt toward its southeastern tip. Positive oroclinal tests along the MTB suggest the occurrence of oroclinal bending that curved the originally straight MTB before and during the deposition of its lower part, and nearly half of the bending had occurred during the deposition of its upper part. This oroclinal bending is mostly attributed to the northward indentation of the West Kunlun Mountains along the décollement salt‒gypsum layers and further implies ∼7.9° absolute clockwise rotation of the Tarim Basin since the late Miocene. Integrating these findings with other lines of geological evidence around the Tarim Basin, we propose that episodic widespread tectonic deformation with basinward propagation occurred since the late Miocene due to the far-field effect of the continuous northward indentation of the Indian Plate into Eurasia.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"54 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141567671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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