Tectonophysics最新文献

{"title":"Evidence of the West Java back-arc thrust from earthquake activity","authors":"Pepen Supendi ,&nbsp;Sri Widiyantoro ,&nbsp;Nicholas Rawlinson ,&nbsp;Mudrik R. Daryono ,&nbsp;A. Ardianto ,&nbsp;Aria Widhi Baskara ,&nbsp;Ruben Damanik ,&nbsp;Yayan M. Husni","doi":"10.1016/j.tecto.2025.230853","DOIUrl":"10.1016/j.tecto.2025.230853","url":null,"abstract":"<div><div>In this study, a borehole seismic experiment was designed to investigate seismic activity associated with the West Java back-arc thrust. This passive source experiment was composed of seven borehole seismometers that extended across the Subang region and surrounding areas. The experiment recorded seismic data between December 2022 and September 2023 and was supplemented by data from the Agency for Meteorology, Climatology, and Geophysics of Indonesia (BMKG) permanent seismic station network. During the recording period of the temporary array, we identified and located 15 shallow crustal earthquakes and computed their focal mechanisms. The occurrence of thrust-type earthquakes in the back-arc region during this period offers evidence of continued tectonic activity along the West Java back-arc thrust. Our integrated analysis, which incorporates geological studies and previous research, reveals a complex fault network comprising the Citarum Front Fault, Citarum Fault, and Baribis Fault system, indicating significant horizontal and vertical changes in the regional stress field. Furthermore, we identify a previously unrecognized fault, which we call the Cirata Fault, which is characterised by earthquakes with thrust mechanisms. Intriguingly, we observe normal faulting at the eastern end of the Lembang Fault, suggesting reactivation of old fault structures associated with the ancient Sunda Caldera. These findings have significant implications for seismic hazard assessment and disaster preparedness in the region, and highlights the importance of continuous monitoring and collaborative efforts among geologists, seismologists, urban planners, and policymakers.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230853"},"PeriodicalIF":2.7,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144621957","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":"Plio–Pleistocene stratigraphy of the Horcón Basin (central Chile, ∼33°S): Transgressive–regressive cycles and forearc deformation above the Juan Fernández Ridge","authors":"L. Pinto ,&nbsp;M. San Juan ,&nbsp;T. Villaseñor ,&nbsp;M.P. Rodríguez ,&nbsp;V. Flores-Aqueveque ,&nbsp;M. Naipauer ,&nbsp;J.P. Le Roux ,&nbsp;R. Cuevas","doi":"10.1016/j.tecto.2025.230851","DOIUrl":"10.1016/j.tecto.2025.230851","url":null,"abstract":"<div><div>This paper analyzes the marine and continental successions of the Neogene to Quaternary Horcón Basin (32°–33°S), a forearc basin of the Central Andes, based on sedimentological, stratigraphic, and U<img>Pb detrital zircon geochronological data. The basin lies above the present-day projection of the Juan Fernández Ridge (JFR), which has been subducting beneath the South American Plate at a fixed piercing point over the past ∼10 million years. An initial transgressive episode (Late Pliocene) is recorded in successions that grade from middle transitional to deeper offshore settings. A prominent erosional surface overlying these deposits marks a subsequent regressive phase. This was followed by a second transgression (Early Pleistocene?), preserved in a deepening-upward sequence dominated by gravelly upper shoreface to foreshore facies. A later regression (Early to Middle Pleistocene?) is expressed by debris flow deposits and extensive alluvial braidplains progradationally advancing toward the coast. Detrital zircon U<img>Pb ages and gravel composition indicate sediment sources from Jurassic and Cretaceous arc rocks of the Coastal Cordillera throughout the basin's evolution, with a significant contribution from the Principal Cordillera possibly linked to tectonic activity upstream of the Aconcagua River. We suggest that the first transgressive episode may reflect regional subsidence, whereas the subsequent regression could be associated with regional uplift of the South American margin at these latitudes. Additionally, the transgressive–regressive cycles documented in the Horcón Basin likely record localized vertical motions driven by coastal normal faulting, resulting in high-relief coastal blocks and embayments. While further evidence is needed, we propose that this complex deformation history, occurring within an overall compressive regime, may have been modulated by the subduction of JFR seamounts, contributing to localized subsidence and uplift along the margin of the overriding plate.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"912 ","pages":"Article 230851"},"PeriodicalIF":2.7,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144621935","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":"Differential deformation mechanisms in the northeastern Tibetan plateau modulated by lithospheric heterogeneities","authors":"Zhuo Ye ,&nbsp;Andrew V. Zuza ,&nbsp;Xingfu Huang ,&nbsp;Xiaosong Xiong ,&nbsp;Rui Gao","doi":"10.1016/j.tecto.2025.230852","DOIUrl":"10.1016/j.tecto.2025.230852","url":null,"abstract":"<div><div>Determining the driving mechanisms for distributed intracontinental deformation is an important topic in continental tectonics. The ∼2000-km-wide Cenozoic Himalayan-Tibetan orogen and the related thickened Tibetan plateau represent an archetypical continent-continent collision to study intra-plate deformation. There are two debated paradigms for how this orogen accommodates plate convergence. The first highlights the motion and translation of rigid blocks, whereas the second quantifies lithospheric deformation as a flowing continuum. Both models have been used to quantify deformation at the northeastern margin of the Tibetan plateau, which deforms far from any plate-boundary interactions. To interrogate this issue, here we use seismic profiling data collected in northeastern Tibet to conduct new S-wave receiver functions, joint inversion imaging, and regional synthesis to develop a comprehensive lithosphere-scale structural model of the differential deformation mechanisms operating along the northern and eastern margins of the Tibetan plateau. The northern plateau margin is dominated by a complex lithospheric thrust-wedge system with multiple detachment zones that accommodate intracontinental oblique underthrusting/subduction. Conversely, the eastern plateau margin does not exhibit discrete fault structures and appears to deform via the vertical inflation of a hot and weak mid-lower crust induced by mantle melting. We attribute these different styles of deformation to significant vertical and lateral lithospheric heterogeneities, governed primarily by temperature variations reflecting the recency of Cenozoic volcanism and pre-Cenozoic terrane accretion. Our results provide comprehensive insights into the intraplate processes and geodynamics that shape the development of a continental collisional zone.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230852"},"PeriodicalIF":2.7,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144621958","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":"Physics-based simulations of earthquake scenarios on the Kopili fault in Northeast India: Insights into seismic hazard and fault mechanics","authors":"T.C. Sunilkumar ,&nbsp;Zhenguo Zhang ,&nbsp;Zijia Wang ,&nbsp;Zhongqiu He ,&nbsp;Danhua Xin ,&nbsp;Tianhong Xu ,&nbsp;Wenqiang Wang","doi":"10.1016/j.tecto.2025.230838","DOIUrl":"10.1016/j.tecto.2025.230838","url":null,"abstract":"<div><div>Understanding the seismic risks associated with the Kopili fault (KF) in northeast India is essential for effective risk management. We employed advanced physics-based dynamic rupture simulation scenarios to quantify the fault’s potential for generating damaging earthquakes. Our models indicate that the central KF segment can produce significant earthquakes with moment magnitudes (Mw) potentially reaching 7.3, and possibly up to 7.5. The analysis revealed considerable variability in rupture extent and ground motion characteristics, strongly influenced by fault and model parameters. A detailed stress inversion analysis shows that the maximum horizontal stress (<span><math><msub><mrow><mi>S</mi></mrow><mrow><mtext>H</mtext></mrow></msub></math></span>) is oriented at <span><math><mo>∼</mo></math></span>N41°E within an oblique-reverse stress regime, significantly impacting rupture behavior. Rupture simulations indicate that earthquakes originating from the central segment of the fault produce the largest rupture areas and the most intense ground shaking, with peak ground velocities exceeding 0.6 m/s and corresponding intensities of MMI VIII and above. Sensitivity analyses highlight the critical roles of nucleation points, dynamic rupture parameters and <span><math><msub><mrow><mi>S</mi></mrow><mrow><mtext>H</mtext></mrow></msub></math></span> orientation in determining rupture propagation and ground motion distribution. Notably, minor adjustments in <span><math><msub><mrow><mi>S</mi></mrow><mrow><mtext>H</mtext></mrow></msub></math></span>, such as a 10° variation, can lead to substantial changes in rupture characteristics, including extreme scenarios reaching Mw 7.5 in the counterclockwise stress rotation. Additionally, supershear effects observed in several scenarios likely stem from initial stress variations along the fault. The physics-based simulation of ground motion shows that, compared to ground motion prediction equations (GMPEs) estimates, it provides more reliable predictions. These insights enhance our understanding of how these parameters influence earthquake dynamics and are vital for developing effective earthquake risk management strategies in northeast India. By integrating physics-based dynamic rupture modeling with empirical ground motion predictions, our study could provide a robust framework for seismic hazard assessment in the KF zone and similar tectonic settings.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230838"},"PeriodicalIF":2.7,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596140","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":"Seismogenic independence of earthquake doublet: Insights from the 2023 Kahramanmaraş, Türkiye earthquake sequence","authors":"Kexu Shi ,&nbsp;Weijia Sun ,&nbsp;Xu Zhao ,&nbsp;Erdinc Saygin ,&nbsp;Zhipeng Zhang","doi":"10.1016/j.tecto.2025.230850","DOIUrl":"10.1016/j.tecto.2025.230850","url":null,"abstract":"<div><div>The interplay between large earthquake doublets often involves a triggering mechanism, yet the specifics of their interaction during the seismogenic process remain poorly understood. Here, we examine the seismogenic relationship using the 2023 Kahramanmaraş, Türkiye earthquake doublet. By analyzing repeating earthquakes (REs) prior to the two 2023 events, we estimated the pre-seismic deep slip rates along the East Anatolian Fault (EAF) and assessed fault movement. Utilizing two distinct earthquake relocation techniques, we identified REs and improved the accuracy of their locations. Our findings reveal a higher deep slip rate of approximately 20 mm/year at the Maras triple junction (MTJ) of the EAF, contrasting with previous estimates based on surface fracture observations. The dense clustering of REs at the MTJ suggests that the seismogenic zone of the first event was weakly coupled and may have undergone accelerated creep before the doublet. Conversely, the seismogenic zone of the second event showed minimal seismic activity and a lack of REs. Integrating these results with regional tectonic data, we suggest that the seismogenic environments of the doublet are markedly different, indicating that the seismogenic processes of the two events are largely independent.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230850"},"PeriodicalIF":2.7,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596269","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":"Cenozoic evolution of the Great Arc of the Caribbean and Lesser Antilles slabs: A perspective from a 3D numerical subduction model","authors":"A. Bayona ,&nbsp;V.C. Manea ,&nbsp;S. Yoshioka","doi":"10.1016/j.tecto.2025.230849","DOIUrl":"10.1016/j.tecto.2025.230849","url":null,"abstract":"<div><div>The Caribbean Plate features a unique tectonic setting and evolution, controlled by the interaction among Cocos, Nazca, North American, and South American Plates. Presently, the Caribbean Plate experiences active subduction on both lateral sides, along the Middle American Trench to the west and the Lesser Antilles Trench to the east. Subduction along the Great Arc of the Caribbean was active from the Early Cretaceous until the Eocene. In this study, we conducted 3D numerical simulations of subduction tailored to the tectonic evolution of the Caribbean Plate using plate reconstructions as kinematic boundary conditions. This study introduces the first numerical model that spans the complete subduction history of the Lesser Antilles. Our 3D numerical simulations focus on the subduction processes involving the Great Arc of the Caribbean and the Lesser Antilles in the northeastern region of the Caribbean Plate since the onset of the Cenozoic era, incorporating pre-existing slabs from earlier subduction. For the Great Arc of the Caribbean, we observe a west-to-east propagating slab detachment that correlates with the cessation of subduction and arc volcanism. In contrast, in the Lesser Antilles, we detail the slab trajectory at the mantle transition zone-lower mantle boundary, where it stagnates due to the combination of a higher viscosity of the lower mantle and the negative Clapeyron slope of the phase transition from ringwoodite to bridgmanite + ferropericlase. Our findings highlight dynamic mechanisms driving slab flattening and lateral motion, including trench retreat and rollback. Finally, the model predicts the existence of corner flow in the mantle wedge and trench-parallel sub-slab flow, in agreement with observed seismic anisotropy patterns. Our conclusions align with prior research and enhance the understanding of how trench retreat, slab detachment and phase transitions have shaped the evolution of the Great Arc of the Caribbean and Lesser Antilles slabs.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230849"},"PeriodicalIF":2.7,"publicationDate":"2025-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580760","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":"Mantle upwelling induced by a bilateral convergent double subduction during Late Paleozoic in Eastern Tianshan, NW China: Evidence from high-resolution magnetotelluric profile","authors":"Ying Liu ,&nbsp;Chao Chen ,&nbsp;Yinhe Luo ,&nbsp;Jinsong Du ,&nbsp;Qing Liang ,&nbsp;Graham Heinson","doi":"10.1016/j.tecto.2025.230839","DOIUrl":"10.1016/j.tecto.2025.230839","url":null,"abstract":"<div><div>Late Paleozoic oceanic subduction has been proposed for the formation of Eastern Tianshan, NW China, situated in the southern Central Asian Orogenic Belt. However, the patterns and consequences of the subduction remain undetermined. To identify the mode of the Late Paleozoic subduction, a high-resolution magnetotelluric (MT) long-profile across Eastern Tianshan was deployed. A three-dimensional (3D) inversion was conducted to obtain the resistivity model beneath the profile. The most obvious feature in the resistivity model is a well-developed conductor (∼30 Ωm) beneath Turpan-Hami Basin from ∼15 km depth extending to the uppermost mantle. This conductor is preferably ascribed to the metamorphic fluids from an ancient mantle upwelling. In addition, the MT observation suggests a double subduction in the south Kangguer suture, together with a southward dipping subduction in the north Kalamaili Fault during the Late Paleozoic. The bilateral convergent double subduction induced the mantle upwelling and controlled the initial extensional environment during Late Paleozoic in the Turpan-Hami Basin.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230839"},"PeriodicalIF":2.7,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144572277","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":"Hydration and petrologic changes of inner portions of the subducting oceanic lithosphere facilitated by intermediate-depth faulting","authors":"M. Scambelluri ,&nbsp;G. Toffol ,&nbsp;E. Cannaò ,&nbsp;D. Belmonte ,&nbsp;N. Campomenosi ,&nbsp;S. Cacciari ,&nbsp;G. Pennacchioni","doi":"10.1016/j.tecto.2025.230832","DOIUrl":"10.1016/j.tecto.2025.230832","url":null,"abstract":"<div><div>The subduction-zone rheology and seismic behaviour of hydrated oceanic slabs have been widely studied, while the unaltered, dry portions of the subducting lithosphere remain less understood despite their role in earthquake generation and slab pull through eclogitization. We present field-based evidence from the ophiolitic Lanzo Massif (Western Alps), a slice of oceanic lithosphere composed of mantle peridotite and small volumes of gabbro which largely escaped hydration and Alpine metamorphism, representing a mechanically rigid block in the subduction complex. At intermediate depths, this dry lithosphere locally developed pseudotachylyte-bearing faults (e.g. the Moncuni locality) and widespread meso- to micro-faults (e.g., the Mt. Arpone locality). At Mt. Arpone, faults offset the gabbroic dykes by several centimetres: they contain sub-micrometric “annealed” ultramafic ultracataclasite of olivine, pyroxene and spinel, locally overgrown by chlorite and orthopyroxene. These features indicate faulting under dry conditions, which produced a tectonic porosity and enabled localized fluid infiltration. This led to discontinuous hydration of peridotite and to the widespread transformation of cataclastic gabbroic plagioclase into high-pressure zoisite-paragonite symplectites. Thermodynamic modelling suggests that plagioclase breakdown during faulting occurred under blueschist-facies conditions. Recent petrological studies show that this reaction is associated to volume reduction and the formation of reactive porosity, making plagioclase the most intensely eclogitized mineral in the studied samples. Trace element analyses reveal that fluid infiltration drove the internal (closed-system) redistribution of fluid-mobile elements. Eclogitization of the Lanzo peridotite and gabbro only occurred where fluids were present, either from limited oceanic hydration, or from subduction-related fluid infiltration through faults and the porosity created by the metamorphic breakdown of gabbroic plagioclase. The Arpone blueschist-facies ultracataclasites may represent seismic structures that did not evolve into frictional melting; they may be the precursors to the earthquake-generating faults that developed at Moncuni.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230832"},"PeriodicalIF":2.7,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144570317","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":"Anisotropy of the thermal conductivity, thermal expansion coefficient, and seismic wave velocity in the oceanic lithosphere–asthenosphere system","authors":"M. Morishige","doi":"10.1016/j.tecto.2025.230822","DOIUrl":"10.1016/j.tecto.2025.230822","url":null,"abstract":"<div><div>Previous numerical studies have considered complex material properties in investigations of the thermal structure of oceanic plates, although the properties are assumed to be isotropic. This study focused on anisotropic thermal conductivity and expansion coefficients related to the crystallographic-preferred orientation of mantle minerals, and the effects of this anisotropy on the thermal structure of oceanic plates and associated surface heat flow, seafloor subsidence, and seismic anisotropy. A steady-state temperature and rock flow velocity are obtained in a two-dimensional model domain near a mid-ocean ridge. The results show that anisotropic thermal conductivity increases the mantle temperature by up to 18–28 K for oceanic crust with an age of 60 Myr, depending on the assumed half-spreading rate, because the vertical component of the conductivity is lower than the isotropic value. The effects on surface heat flow are minor. Anisotropy of the thermal expansion coefficient results in a small increase in seafloor subsidence, as the vertical component of the thermal expansion coefficient is higher than the isotropic case. Incorporating the effects of enstatite leads to a reduced anisotropy for the thermal conductivity and expansion coefficient. The increase in mantle viscosity due to dehydration associated with partial melting has a large effect on the seismic anisotropy. This leads to an abrupt, largely age-independent increase in azimuthal and radial anisotropy at <span><math><mo>∼</mo></math></span>60 km depth, which may explain some seismic observations.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230822"},"PeriodicalIF":2.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515667","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":"Gravitational instability of thickened yet compositionally buoyant Tibetan mantle lithosphere","authors":"Gregory A. Houseman ,&nbsp;Philip C. England ,&nbsp;Lynn A. Evans","doi":"10.1016/j.tecto.2025.230837","DOIUrl":"10.1016/j.tecto.2025.230837","url":null,"abstract":"<div><div>The Tibetan plateau, one of the major topographic features of the Earth, presents many unanswered questions regarding its evolution, present structure, and continuing geological activity. The extensive crustal thickening that is attributed to continental convergence between India and Eurasia sustained for the past 55 Myr, and continuing today, is underlain by an upper mantle in which relatively fast shear-wave speeds are measured to depths of 200 km and more. Although the high elevation of the plateau can be attributed mainly to the thickness of the crust, the observation that the plateau is now extending is evidence that the lithosphere has increased its gravitational potential energy since it was thickened. Extensive volcanism during the current continental collision additionally implies that the lithosphere and/or uppermost mantle of Tibet was re-heated. Replacement of mantle lithosphere by asthenosphere in a convective thinning process has been advanced as an explanation of that re-heating, but that process has been difficult to reconcile with the high shear-wave velocities measured in the upper mantle beneath the plateau. However, a model based on a restricted overturn of a depleted, metasomatised, mantle lithosphere in the upper 200 km of the mantle can reconcile these apparently contradictory observations. Such overturn can explain how the observed distribution of seismic velocities has been produced, how heat is injected into the lithosphere producing transient uplift, and how mantle-derived melts can rapidly reach the base of the crust in widely distributed locations across the plateau.</div></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"911 ","pages":"Article 230837"},"PeriodicalIF":2.7,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515668","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}