Journal of Geophysical Research: Solid Earth最新文献_第2页

Gravitationally Unstable Hydrous Melts at the Base of the Upper Mantle

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-23 DOI: 10.1029/2024JB030737

Hongzhan Fei, Juan Chen, Fei Wang, Baohua Zhang, Qunke Xia, Tomoo Katsura

引用次数: 0

Link Between the Impact Mechanisms of Granular Flow-Dam Interaction and the Generated Seismic Signal: Insights From Laboratory Experiments

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-22 DOI: 10.1029/2024JB029946

Xinzhi Zhou, Yifei Cui, Jun Fang, Hui Tang, Zhen Zhang, Shuofan Wang

{"title":"Link Between the Impact Mechanisms of Granular Flow-Dam Interaction and the Generated Seismic Signal: Insights From Laboratory Experiments","authors":"Xinzhi Zhou, Yifei Cui, Jun Fang, Hui Tang, Zhen Zhang, Shuofan Wang","doi":"10.1029/2024JB029946","DOIUrl":"10.1029/2024JB029946","url":null,"abstract":"To manage debris flows, it is critical to both recognize potential impact mechanisms and evaluate, via physical models, associated impact forces. Seismic signals can be used to detect flows and infer flow properties, but inferring flow characteristics in channels with check dams and upslope deposits remains challenging. In this study, we conducted laboratory flume experiments to investigate the influence of varying flume inclination and pre-retained material (deposition upslope of the barrier) height on flow characteristics and impact mechanisms, and analyzed their correlation with seismic signals. The objective was to examine the impact of deposition upslope of the barrier on interactions between debris flows and check dams by combining seismic and dynamic parameters. We found that a frequency domain feature-based method can successfully filter out noisy signals. Results showed that it is possible to distinguish the impact mechanism of a granular flow in the presence of deposition upslope of the barrier from the seismic signals' attributes, that is, the peak signal amplitude envelope before granular flow overflow and its ratio to the peak amplitude of the control test without the barrier. Furthermore, the presence of check dams and upslope deposits in the debris flow channel significantly reduces the sensitivity of seismic signals to flow velocity. A key advantage of using the peak amplitude of the seismic signals generated by debris flows for identifying the impact mechanism is the potential for enhanced safety and cost-effectiveness compared with contact monitoring instruments such as force plates.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857683","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}

引用次数: 0

Freezing of Crystal Preferred Orientation in the Mantle Wedge Corner and Shear Wave Splitting

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-22 DOI: 10.1029/2024JB030062

Lindsey M. Kenyon, Ikuko Wada

{"title":"Freezing of Crystal Preferred Orientation in the Mantle Wedge Corner and Shear Wave Splitting","authors":"Lindsey M. Kenyon, Ikuko Wada","doi":"10.1029/2024JB030062","DOIUrl":"10.1029/2024JB030062","url":null,"abstract":"Using numerical models, we compute the evolution of the mantle flow field and the crystal preferred orientation (CPO) of mineral aggregates in the mantle wedge of generic subduction systems from their nascent to mature stage and investigate shear wave splitting (SWS) through the forearc mantle wedge corner and overriding crust. Upon subduction initiation, the maximum depth of slab-mantle decoupling (MDD) is relatively shallow (∼20 km depth), resulting in mantle flow and CPO development in the wedge corner. As subduction continues, the MDD deepens, the wedge corner cools and stagnates, and the olivine CPO becomes frozen-in. In the cool wedge corner, antigorite can form if water is available. In non-deforming mantle, antigorite CPO develops relative to the host olivine CPO through topotactic growth. We calculate splitting parameters of synthetic local S waves based on the model-predicted A- and B-type olivine CPOs and topotactically grown antigorite CPO that replaces A-type olivine CPO in the wedge corner. The fast direction is trench-normal for A-type olivine and antigorite CPOs and trench-parallel for B-type. When the delay times are long enough (>0.1 s), we find them positively correlated with the thickness of the mantle wedge corner. In NE Japan, where the results of detailed analyses on the spatial variation of the SWS parameters are available, such correlation is not observationally reported. However, the addition of an anisotropic overriding crust provides delay times (∼0.1 s) and trench-normal fast directions that are consistent with the local SWS observations.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030062","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Controls of Grain Breakage on Shear Band Morphology and Porosity Evolution in Fault Gouges 晶粒破碎对断层沟剪切带形态和孔隙率演变的控制作用

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-21 DOI: 10.1029/2024JB029255

Qiang Li, Jianye Chen, Chongyuan Zhang, Liang Yuan, Derek Elsworth, Quan Gan, Fengshou Zhang

{"title":"Controls of Grain Breakage on Shear Band Morphology and Porosity Evolution in Fault Gouges","authors":"Qiang Li, Jianye Chen, Chongyuan Zhang, Liang Yuan, Derek Elsworth, Quan Gan, Fengshou Zhang","doi":"10.1029/2024JB029255","DOIUrl":"https://doi.org/10.1029/2024JB029255","url":null,"abstract":"Gouge in fault zones generally undergoes grain breakage during shear slip events, resulting in changes in both shear mode and pore structure. We establish a discrete element model representing shearing of granular fault gouge for increasing normal stresses but constant shear velocity (v = 6 μm/s) to investigate the effects of grain breakage on shear band development and the evolution of fault friction and porosity. An increase in normal stress increases frictional strength by ∼20% accompanied by many small slip events triggered by grain breakage. The fragments generated by grain breakage reduce mean grain size and shift the grain size. Dilation and an absence of comminution under low normal stress increase porosity countered by high normal stress developing rapid compaction and grain breakage and decreasing porosity. We propose a concept of porosity evolution linked to volumetric strain. An increase in normal stress results in the principal breakage mechanism evolving from low efficiency abrasion to high efficiency splitting with grain size distribution converging to fractal distributions observed in nature. Heterogeneous grain breakage drives local reduction in porosity, the redistribution of contact stresses and realignment of force-chains, changing the slip pattern and microstructural characteristics through shear band development. At low normal stress, the grain deformation is mainly accommodated by slipping and rolling and the shear bands are dominated by Y shears. With the increase in normal stress, grain breakage promotes the development of the more highly inclined R shears.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852763","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}

引用次数: 0

Water Dissolution Driving High Mobility of Diopside-H2O Supercritical Fluid

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-19 DOI: 10.1029/2024JB030956

Bowen Chen, Jian Song, Yu Zhang, Wenzhong Wang, Yajie Zhao, Zhongqing Wu, Xiaoping Wu

{"title":"Water Dissolution Driving High Mobility of Diopside-H2O Supercritical Fluid","authors":"Bowen Chen, Jian Song, Yu Zhang, Wenzhong Wang, Yajie Zhao, Zhongqing Wu, Xiaoping Wu","doi":"10.1029/2024JB030956","DOIUrl":"https://doi.org/10.1029/2024JB030956","url":null,"abstract":"Supercritical geo-fluid serves as an ideal agent for chemical transport in the subduction zone. Yet the nature of its structure and transport properties remains elusive. Here, we provide comprehensive investigations on the atomic structures and transport properties of diopside-H2O system (with 0–78 wt% H2O) at 0–12 GPa and 3,000 K, based on first-principles molecular dynamics simulations. Our results reveal the prevailing coexistence of both Si-OH and Mg/Ca-OH, with the latter arising from charge compensation by the more predominate Mg/Ca-OH2 species. The incorporation of water constantly disrupts the silicate network by converting the bridging oxygens (BOs) to non-bridging oxygens (NBOs), generating more isolated, diffusible, yet stable silicate clusters (such as monomers or oligomers), with lower coordination numbers, longer species lifetimes and more stretched bond angles. The dissolution of water significantly facilitates the diffusivities of all species, while reducing the shear viscosity. The strong linear correlations between the diffusivities/viscosity and the degree of polymerization underscore the water-induced depolymerization as the primary mechanism driving the high mobility of supercritical fluids. The viscosity contrast between anhydrous and hydrous melts could cause the substantial differences in magma mobility and ascent rates, leading to the diverse radioactive isotope patterns between the melt-source and fluid-source arc lavas. Our results highlight the critical role of water in shaping the structure and transport properties of silicate-H2O system, and emphasize the potential importance of supercritical fluids within the subduction-related magmatism and mineralization processes.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850990","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}

引用次数: 0

Comparison of Paleoearthquake Elapsed-Times and Mean Interevent-Times for a Global Data Set of Active Faults: Implications for Future Earthquakes and Seismic Hazard

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-18 DOI: 10.1029/2024JB030036

Vasiliki Mouslopoulou, Andrew Nicol, Andrew Howell, Jonathan D. Griffin

{"title":"Comparison of Paleoearthquake Elapsed-Times and Mean Interevent-Times for a Global Data Set of Active Faults: Implications for Future Earthquakes and Seismic Hazard","authors":"Vasiliki Mouslopoulou, Andrew Nicol, Andrew Howell, Jonathan D. Griffin","doi":"10.1029/2024JB030036","DOIUrl":"https://doi.org/10.1029/2024JB030036","url":null,"abstract":"The timing and size of successive prehistoric earthquakes on individual active faults are key for understanding seismic processes and time-dependent seismic hazards. Here, we analyze interevent and elapsed times for 890 large prehistoric and historic earthquakes on 210 normal, reverse and strike-slip faults from five active tectonic regions globally (Japan, Greece, New Zealand and the California & Basin-and-Range provinces in the US). Most faults (∼80%) have mean interevent times greater than the elapsed time (open-interval) since their last recorded earthquake. We also find that 85%–100% of closed interevent times, defined by 64 historic ruptures and their penultimate events on these faults, occurred within a factor of two of their mean recurrence-interval, with 75% less than the mean. These observations hold for a variety of tectonic settings and fault parameters, with faster slip-rate faults (>10 mm/a) being consistently more “advanced” in their seismic-cycle than slower moving faults. The entire global population of closed interevent-times is consistent with a Weibull probability density function (PDF), while stochastic modeling tailored to closed-interval parameters indicates that open recurrence-interval data sets are best “predicted” by positively skewed elapsed time distributions (52%–78% overlap integral) for all regions, except California. Thus, the rarity of elapsed times exceeding mean interevent-times on individual faults may be due to skewed recurrence PDFs (i.e., Brownian Passage Time, lognormal, etc.), in which the median and mode are less than its mean, while California is an outlier potentially because its open-intervals derive from a single geometrically interconnected fast-moving (>10 mm/a) fault system that is presently experiencing an earthquake-hiatus.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Magnetic Telechemistry of the Reykjanes Ridge

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-18 DOI: 10.1029/2024JB030622

Daniel Thorhallsson, Fernando Martinez, Richard Hey, Ármann Höskuldsson

{"title":"Magnetic Telechemistry of the Reykjanes Ridge","authors":"Daniel Thorhallsson, Fernando Martinez, Richard Hey, Ármann Höskuldsson","doi":"10.1029/2024JB030622","DOIUrl":"https://doi.org/10.1029/2024JB030622","url":null,"abstract":"The magnetic telechemistry hypothesis proposes that hotspot mantle contains elevated Fe and Ti leading to enhanced crustal magnetic anomaly strength. Ridge segmentation and other geologic factors also influence oceanic crustal magnetization, potentially complicating the identification of a hotspot signature. At the Reykjanes Ridge, distinct segmented (offset) and unsegmented (linear axis) crustal terrains formed at different times over the Iceland hotspot allow an examination of these effects as well as contrasting hotspot models. We use ship magnetic anomaly data to invert for basement magnetization and examine variations in its root-mean-square intensity. We find that the unsegmented “linear” terrains indeed have greater magnetization intensities than the “segmented” terrain, in agreement with some models in which mantle plume material advanced, retreated, and advanced again forming these terrains. However, we also resolve a magnetization intensity low centered along a flowline at 61°N that cuts across the basin and coincides on axis with a previously identified geochemical boundary. We conclude that crustal age, resolution effects, and ridge segmentation create the main magnetization variations among the various terrains of the Reykjanes Ridge. The coincidence of a major geochemical boundary with a basin-crossing magnetization low, however, indicates a stably zoned hotspot mantle anomaly rather than a rapidly upwelling and radially flowing mantle plume.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846125","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}

引用次数: 0

Normal Fault Interactions in Seismic Cycles and the Impact of Fault Network Geometry

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-18 DOI: 10.1029/2024JB030382

Constanza Rodriguez Piceda, Zoë K. Mildon, Martijn van den Ende, Jean-Paul Ampuero, Billy J. Andrews

{"title":"Normal Fault Interactions in Seismic Cycles and the Impact of Fault Network Geometry","authors":"Constanza Rodriguez Piceda, Zoë K. Mildon, Martijn van den Ende, Jean-Paul Ampuero, Billy J. Andrews","doi":"10.1029/2024JB030382","DOIUrl":"https://doi.org/10.1029/2024JB030382","url":null,"abstract":"Understanding the mechanisms behind the characteristics of earthquake cycles on normal faults is challenging due to their long recurrence times. Despite their moderate magnitude, normal faulting earthquakes can produce considerable damage. We investigate the effects of fault network geometry and spacing on the seismic cycle of two normal faults modeled with rate-and-state friction and elastic interactions. Our analysis examines how variable along-strike and across-strike distances between faults influence cycle periodicity, synchronicity, nucleation location, magnitude-frequency distribution, and rupture characteristics. To isolate network-geometry effects from dimensional and frictional effects, we model faults with a seismogenic width (W) over characteristic nucleation length (L∞) ratio such that isolated faults produce periodic cycles with a characteristic magnitude (Mw) of 5.1. The cycle periodicity and Mw of earthquakes change depending on the spacing and geometry of the fault network. Faults become less periodic at short across-strike distances (≤0.2 km). Decreasing the across-strike spacing leads to variable hypocenter locations and the emergence of partial ruptures, producing magnitudes down to Mw 4.4 at spacings ≤0.2 km. Cycle periodicity and Mw remain unaffected by along-strike spacing. The long-term synchronization state of the faults' seismic cycle is influenced differently by across-strike and along-strike distances. Closely spaced faults (≤10 km) across-strike display variable degrees of synchronization, whereas faults arranged along-strike tend to evolve toward more synchronized states as along-strike separation decreases. Fault network geometry plays a prominent role, with across-strike distance having a larger effect on interevent time and rupture style variability than along-strike distance.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030382","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Deep Dive Into a Ridge-Transform Fault Intersection: Volcano-Tectonic Relationships in an Enhanced Cold-Edge Effect at the Romanche Fracture Zone

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-18 DOI: 10.1029/2024JB030688

Léa Grenet, Marcia Maia, Cédric Hamelin, Anne Briais, Hervé Guillou, Vincent Scao, Daniele Brunelli

{"title":"A Deep Dive Into a Ridge-Transform Fault Intersection: Volcano-Tectonic Relationships in an Enhanced Cold-Edge Effect at the Romanche Fracture Zone","authors":"Léa Grenet, Marcia Maia, Cédric Hamelin, Anne Briais, Hervé Guillou, Vincent Scao, Daniele Brunelli","doi":"10.1029/2024JB030688","DOIUrl":"https://doi.org/10.1029/2024JB030688","url":null,"abstract":"At mid-ocean ridges, the mantle temperature and composition, and the lithosphere thickness control the melting conditions, which influence the feeding and structure of the neo-volcanic areas. We present a study of the eastern intersection between the Romanche transform fault (TF) and the adjacent southward segments of the Mid-Atlantic Ridge (MAR). A strong thermal gradient is expected along the axis. We focus on the construction of the axial domain and on the spatial and temporal volcano-tectonic interplays. The geological mapping of the intersection shows a progressive variation in the orientation of the normal faults from about 30° to 90° oblique to the spreading direction with increasing distance from the TF. This attests to the decrease of the transform-related shear stress component and the thinning of the axial lithosphere southward. Contextually, the coupled thermal edge effect influences the effusion rate and magma supply which in this area are low compared to other MAR segments. However, recent volcanic activity along the axis starts about 10 km south of the ridge-transform intersection. Rather than a progressive increase of the magma supply with the distance from the TF, the volcanic activity seems to increase abruptly about 30 km south of the intersection. The segment RC2, from ∼30 to 55 km from the Romanche TF, displays more numerous and larger seamounts than the segment RC3 located ∼80 km from the TF, an observation which we interpret to result from the increased thickness of the lithosphere under RC2, due to its proximity with the ridge-transform intersection.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB030688","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evidence for Lithospheric Mantle Uniformity Beneath Cratons

IF 3.9 2区地球科学

Journal of Geophysical Research: Solid Earth Pub Date : 2025-04-18 DOI: 10.1029/2024JB029649

Federico D. Munch, Paolo A. Sossi, Amir Khan

{"title":"Evidence for Lithospheric Mantle Uniformity Beneath Cratons","authors":"Federico D. Munch, Paolo A. Sossi, Amir Khan","doi":"10.1029/2024JB029649","DOIUrl":"https://doi.org/10.1029/2024JB029649","url":null,"abstract":"Cratons are characterized by thick mantle roots that have experienced high degrees of partial melting, resulting in a cold, strong, and buoyant mantle compared to its oceanic counterpart. The extent of chemical variability within cratonic roots, the role of cratons in insulating the mantle over time and subsequent triggering of continental break-up, however, remains debated. To better understand the lithospheric and asthenospheric compositional variability of cratons, we combine phase equilibrium computations with the inversion of P-to-s and S-to-p receiver function waveforms and fundamental-mode Rayleigh wave dispersion data recorded at 53 globally distributed seismic stations in different tectonic settings with a focus on cratonic regions. Because existing binary basalt-harzburgite models are unable to account for the variability in Mg# (MgO/[MgO + FeO]) and Mg/Si ratios recorded in xenoliths from cratonic regions, we propose an extension of the binary model that is based on nominally pyroxenite, lherzolite and dunite. The retrieved mantle lithospheric compositions have elevated Mg# (∼90–93) compared to asthenospheric mantle (Mg# ∼89), consistent with their having undergone differing degrees of melt extraction at mean pressures of 3–4 GPa. There are no indications for systematic differences in mantle composition or thermal structure with craton age or location. Instead, we find that the potential temperature of the asthenosphere beneath cratons is roughly 50°C cooler than the surrounding ambient mantle. This suggests that the insulating (i.e., heating) effect of continents may not be as prominent as implied by dynamical studies simulating the exchange of heat and material across the mantle.","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 4","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB029649","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143849244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0