{"title":"Formation mechanism and characteristics of longitudinal cracking on embankment with TPCTs in permafrost regions of the QTP","authors":"Qinguo Ma, Yuanming Lai, Xiaoxiao Luo, Haiyong Chen, Peifeng He, Xiaojie Lin","doi":"10.1016/j.enggeo.2025.107927","DOIUrl":"https://doi.org/10.1016/j.enggeo.2025.107927","url":null,"abstract":"Owing to high cooling efficiency without external cooling requirement, two-phase closed thermosyphons (TPCTs) play a certain role in maintaining the stability of embankment in permafrost regions of the QTP. However, pavement disease still exists in the embankments with TPCTs along the Qinghai-Tibet Highway (QTH). We aimed to summarize the type, position and characteristics of pavement disease, and determine the cause, emergence time, and spatiotemporal evolution of longitudinal cracking. This paper involves an on-site investigation, geological radar detection and multi-physics coupling numerical simulation on the pavement disease of embankments with TPCTs along the QTH. The results show that differential settlement and longitudinal cracking are main pavement disease for embankment with vertical TPCTs (VTPCTs), while longitudinal cracking is the main form for embankment with inclined TPCTs (ITPCTs). Longitudinal cracking in embankment with ITPCTs is more developed than the embankment with VTPCTs. Longitudinal cracking at the pavement is attributed to the combination of ground temperature and soil water distributions, and the inflection point for the deformation distribution is the potential position for longitudinal cracking. In embankment with ITPCTs, longitudinal cracking is initiated at the pavement bottom near sunny side center in the 4th service year and propagates at the sunny side. However, in embankment with VTPCTs, longitudinal cracking is initiated at pavement top surface near EC in the 7th service year and propagates at both sunny and shady sides taking EC as the axis of symmetry. This analysis can provide theoretical guidance for the maintenance of the QTH, and the design for the planned Qinghai-Tibet Expressway.","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"35 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"IceEB: An ensemble-based method to map river ice type from radar images","authors":"Plante Lévesque Valérie, Chokmani Karem, Gauthier Yves, Bernier Monique","doi":"10.1016/j.jag.2024.104317","DOIUrl":"https://doi.org/10.1016/j.jag.2024.104317","url":null,"abstract":"This paper introduces IceEB, i.e., an innovative ensemble-based method that is designed to automate mapping of river ice types using radar imagery. Its goal is the merger of outcomes from three classifiers (IceMAP-R, RIACT, and IceBC) through ensemble-estimation, resulting in a highly performant and fully automated river ice-type map, which is applicable under all meteorological conditions. The first step of our research is the development of a <ce:italic>meta</ce:italic>-classifier and a confidence estimation index, then we validate our method using ground-truth datasets and finally compare the performance between IceEB and the original classifiers. The anticipated outcome was a map exhibiting superior results compared to individual classifiers. Validation and comparison of IceEB employed six RADARSAT-2 HH-HV C-band images that were selected from historical datasets of Quebec and Alberta rivers (Canada). IceEB integrates RADARSAT-2 satellite imagery, a digital elevation model, and a river mask, undergoing preprocessing tasks before activating the three initial classifiers. The <ce:italic>meta</ce:italic>-classifier then performs ensemble-based classification, yielding a legend comprised of water, sheet ice and rubble ice. This approach facilitates broad participation in validation data collection, differentiation between ice covers and ice jams, and minimization of assumptions regarding ice formation. We conclude that IceEB successfully combines existing radar remote sensing ice- classification models to create accurate river ice-type maps. IceEB’s ensemble-based approach outperforms individual classifiers, achieving overall accuracy >91 % for each class. Shortcomings of the original classifiers are effectively offset through parallel use, resulting in marked improvements in automation and generalizability across diverse Canadian meteorological conditions.","PeriodicalId":50341,"journal":{"name":"International Journal of Applied Earth Observation and Geoinformation","volume":"48 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049659","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}
{"title":"Investigation on capturing bedding planes in laminated shale through advanced physics-informed image processing for multiscale geomechanical simulation","authors":"Gaobo Zhao, Mindi Ruan, Deniz Tuncay, Xin Li","doi":"10.1016/j.enggeo.2025.107929","DOIUrl":"https://doi.org/10.1016/j.enggeo.2025.107929","url":null,"abstract":"Shale is characterized by its laminated and fissile nature, consisting of numerous thin layers that easily split along bedding planes. Traditional geomechanical simulations often simplify shale's complex structure by representing bedding planes as continuous and equidistant. While this approach is numerically efficient and useful for approximating general shale behavior, it limits our understanding of the shale's true mechanical response to mining-induced stress. This study proposes an advanced physics-informed image processing method to capture bedding planes across different orientations, scales, and shale types. The method includes five procedures: 1) projection transfer, where a 3D cylinder is projected onto a 2D image; 2) edge detection, where physics-informed edges are detected to obtain bedding plane pixels; 3) clustering, where bedding plane pixels are clustered to form bedding plane lines; 4) representation of bedding planes; and 5) feature extraction of bedding planes. Our method effectively captures bedding planes across different orientations (0°, 45°, and 90°), scales (interim bedding planes at the laboratory scale and ordinary bedding planes at the rock mass scale), and shale types (Opalinus shale, sandy shale, gray shale, black shale, and carbonaceous shale). The geometric information extracted from the bedding planes—including coordinates, number, spacing, length, and distribution characteristics—has been summarized into a comprehensive database for different shales at different scales. The results show that: at the laboratory scale, the captured interim bedding planes are neither continuous nor equidistant. Their lengths follow a log-normal distribution, with the mean length (LN) ranging from 1.227 to 1.823 and the standard deviation (LN) varying between 1.069 and 5.062. The fitting statistical parameters, including the mean and standard deviation of this distribution, have been summarized. At the rock mass scale, the ordinary bedding planes are continuous but not equidistant. Successful multiscale geomechanical simulations in UDEC and FLAC3D were conducted to model uniaxial compression tests at the laboratory scale and shale roof failure at the entry scale, calibrated using laboratory and field observations.","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"34 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hou-Bin Chen, Boda Liu, Wei-Qiang Ji, Shao-Hua Zhang, Kai Zhao, Fu-Yuan Wu
{"title":"Repacking Accelerates High-Silica Melts Extraction: Insights From Microstructural Record and Numerical Modeling","authors":"Hou-Bin Chen, Boda Liu, Wei-Qiang Ji, Shao-Hua Zhang, Kai Zhao, Fu-Yuan Wu","doi":"10.1029/2024gl110970","DOIUrl":"https://doi.org/10.1029/2024gl110970","url":null,"abstract":"Repacking enhances crystal mush permeability, accelerating melt extraction. However, identifying microstructural records of repacking is challenging, creating a gap in quantifying its effect on magmatic reservoirs. We identified extracted melt (rhyolite) and silicic residue (quartz monzonite) through textures and geochemical characteristics in the Pangduo Basin (Southern Tibet; ∼50 Ma old). By calculating interstitial mineral proportions and modeling incompatible element concentrations in quartz monzonite, we estimate a moderate trapped melt fraction (∼50 vol. %), providing microtextural evidence of repacking at intermediate crystallinities. We interpret that the horizontal preferred orientation of frame-forming feldspars produces micro-scale melt channels that accelerate melt extraction. Modeling the intensity of this orientation, we estimated compressive strain to be 20%–30%, likely accelerating melt extraction by at least 15 times. This millennium timescale allows for the growth of a large magma chamber, preventing the melt from freezing or causing multiple small eruptions due to excessive flow-induced stress.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"32 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992336","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}
{"title":"Tourmaline as a textural, geochemical and isotopic marker of fault valve processes recorded at the Paleoproterozoic Lafigué orogenic gold deposit, Ivory Coast","authors":"Alix Hauteville, Anne-Sylvie André-Mayer, Aurélien Eglinger, Julien Perret, Tanguy Nobilet, Yoram Teitler, Brahima Touré, Laurent Ciancaleoni, Lucas Marulier, Yacouba Coulibaly","doi":"10.1007/s00126-024-01335-7","DOIUrl":"https://doi.org/10.1007/s00126-024-01335-7","url":null,"abstract":"<p>The Lafigué gold deposit (Western African Craton, Ivory Coast) is located in the northern part of the Toumodi-Fétékro greenstone belt, and its formation is related to the development of a NNE-SSW-striking sinistral shear zone during the regional D<sub>2</sub> deformation phase. Transpression is evidenced by a contractional jog expressed by E-W-trending, S-dipping thrusts. Boudinaged fault veins and horizontal extension veins infilled by a quartz-calcite-tourmaline-sulfide-gold assemblage have been developed along these thrusts. Two generations of hydrothermal tourmaline have been identified: (1) Tur<sub>2a</sub> relates to a barren event, when (2) Tur<sub>2b</sub> is associated with gold endowment. In situ analyses of major elements and boron isotopic ratios in tourmaline reveal that the precipitation of tourmaline and gold might result from multiple fluid discharges in damaged zones of shear zones as a consequence of fault-valve behaviour. It is expressed by a slight oscillatory zoning within the Tur<sub>2b</sub> crystals, combined with fluctuations in the #Mg within the growth bands (#Mg from 0.56 to 0.63). The overall homogeneous crystal chemistry of Tur<sub>2a</sub> and Tur<sub>2b</sub> (up to 2000 µm), combined with a quite homogenous δ<sup>11</sup>B between the core and the different growth bands (from -20.06 to -18.1 ‰), suggest a crystallisation from geochemically and isotopically relatively homogenous hydrothermal fluids. It suggests that no specific hydrothermal processes (such as fluid mixing, Rayleigh fractionation, changes in temperature or water/rock ratio) were sufficient enough to change the isotopic composition of tourmaline during its growth. We propose that fluid discharge and flash vaporization following the fault failure along the thrusts planes is the main mechanism allowing the crystallization of oscillatory zoned tourmaline and gold at the Lafigué orogenic gold deposit.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"32 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992736","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}
Qian Xiang, Haikun Zhao, Philip J. Klotzbach, Tonghua Su, Chao Wang, Liguang Wu
{"title":"Amplified Bimodal Distribution of Western North Pacific Tropical Cyclone Lifetime Maximum Intensity","authors":"Qian Xiang, Haikun Zhao, Philip J. Klotzbach, Tonghua Su, Chao Wang, Liguang Wu","doi":"10.1029/2024gl111637","DOIUrl":"https://doi.org/10.1029/2024gl111637","url":null,"abstract":"The impact of a warming climate on tropical cyclones (TCs) remains unclear. Here, we find that the probability density function for western North Pacific TC lifetime maximum intensity (LMI) has an amplified bimodal distribution in recent years. This change implies a trend toward more extreme TCs and fewer moderate TCs. Changes in the TC LMI distribution are associated with alterations in the occurrence of rapidly intensifying TCs. Changes in TC tracks, due to alterations in the steering flow linked to a weakening Hadley cell, cause more TCs to move northwestward into a more favorable environment for intensification with large ocean heat content. Consequently, more rapidly intensifying TCs reach higher intensities, significantly contributing to the observed amplified bimodal distribution. These findings provide new insights into changes in TC intensity and highlight the increasing threat to coastal areas from more intense TCs in a warming climate.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"46 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992343","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}
Pierre Linchamps, Emmanuelle Stoetzel, Laurie Amberny, Christine Steininger, Ronald J Clarke, Matthew V Caruana, Kathleen Kuman, Travis Rayne Pickering
{"title":"New modern and Pleistocene fossil micromammal assemblages from Swartkrans, South Africa: Paleobiodiversity, taphonomic, and environmental context.","authors":"Pierre Linchamps, Emmanuelle Stoetzel, Laurie Amberny, Christine Steininger, Ronald J Clarke, Matthew V Caruana, Kathleen Kuman, Travis Rayne Pickering","doi":"10.1016/j.jhevol.2024.103636","DOIUrl":"https://doi.org/10.1016/j.jhevol.2024.103636","url":null,"abstract":"<p><p>The oldest deposit at the hominin-bearing cave of Swartkrans, South Africa, is the Lower Bank of Member 1, dated to ca. 2.2 million years ago. Excavations of this unit have produced a diverse and extensive mammalian fossil record, including Paranthropus robustus and early Homo fossils, along with numerous Oldowan stone tools. The present study focuses on the taxonomic analysis of the micromammalian fossil assemblage obtained from recent excavations of the Lower Bank, conducted between 2005 and 2010, as part of the Swartkrans Paleoanthropological Research Project. The taxonomic composition of this assemblage is dominated by Mystromys, a rodent indicative of grassland environments. Taphonomic analysis indicates an accumulation of prey by Tyto alba (Barn owl) or a related species. Environments inferred from this evidence reflect an open landscape primarily covered by grassland vegetation, but they also feature components of wooded areas, rocky outcrops, and the proximity of a river. The Swartkrans fossil assemblage is compared with Cooper's D (dated to ca. 1.4 Ma) and a modern coprocoenosis of Bubo africanus (spotted eagle-owl) collected within the Swartkrans cave for taxonomic, taphonomic, and paleoecological perspectives. Contrasting fossil and modern micromammalian data provide a better understanding of accumulation processes and facilitate a diachronic reconstruction of changes in climate and landscape evolution. Issues regarding paleoenvironmental reconstruction methodologies based on micromammals are also discussed.</p>","PeriodicalId":54805,"journal":{"name":"Journal of Human Evolution","volume":"200 ","pages":"103636"},"PeriodicalIF":3.1,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143030341","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}
Lingyun Wu, Aizhong Ye, Yunfei Wang, Qiaoqiao Li, Shengsheng Zhan
{"title":"Urbanization influence on changes of extreme precipitation in mainland China","authors":"Lingyun Wu, Aizhong Ye, Yunfei Wang, Qiaoqiao Li, Shengsheng Zhan","doi":"10.1016/j.gloplacha.2025.104720","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2025.104720","url":null,"abstract":"Extreme precipitation events have caused obvious damage to human environments and socioeconomic systems. However, the changes in extreme precipitation and their underlying causes remain unclear. This study analyzed daily precipitation data from 2254 meteorological stations across China from 1981 to 2018, focusing on two key extreme precipitation indicators: Max 1-day precipitation amount (Rx1day) and Max 5-day precipitation amount (Rx5day). Trend analysis was conducted for 17 river basin divisions using the Mann-Kendall method. We also applied the field significance test, a statistical method to evaluate whether a spatial pattern of locally significant results, to determine whether observed trends at individual stations were statistically significant or due to random variation. The results showed that 59.3 % and 58.6 % of the stations exhibited increasing trends in Rx1day and Rx5day, respectively, with significant trends identified at 5.4 % and 4.1 % of the stations. The field significance test revealed a significant increasing in Rx1day across China at the 5 % significance level. Among the 17 sub-basins, significant increases in extreme precipitation were observed in the Inland rivers of Xinjiang and Northern Tibet. The result was consistent with the warming and humidification trends in northwest China. We further analyzed the relationship between urbanization and extreme precipitation by using population density to distinguish rural and urban stations. We found that the spatial distribution of urban stations closely overlapped with stations experiencing increased extreme precipitation, while rural stations corresponded with those showing a decrease. With the progress of urbanization, variations in the trends observed at urban and rural stations have emerged. Nevertheless, urban stations exerted a more pronounced influence on the increasing trend of extreme precipitation.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"40 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055166","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}
Giovanni-Breogán Ferreiro-Lera, Ángel Penas, Sara del Río
{"title":"Obtaining refined Euro-Mediterranean rainfall projections through regional assessment of CMIP6 General Circulation Models","authors":"Giovanni-Breogán Ferreiro-Lera, Ángel Penas, Sara del Río","doi":"10.1016/j.gloplacha.2025.104725","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2025.104725","url":null,"abstract":"Despite the European Mediterranean Region (Euro-Med) being highly vulnerable to climate change the evaluation of General Circulation Models (GCMs) is limited in this region. This research aims to enhance Euro-Med rainfall projections by employing an optimized spatial assessment of 34 CMIP6 GCMs. Firstly, GCMs were interpolated to a common 0.1° grid, matching ERA Land, the reference dataset. Empirical Bayesian Kriging was identified as the most suitable technique, exhibiting the lowest error between raw and interpolated data. After that, annual rainfall interpolated data were compared against ERA5 Land. The performance of GCMs was assessed using five different goodness-of-fit metrics: Normalized Root Mean Squared Error, Nash–Sutcliffe Efficiency, Kling–Gupta Efficiency, Coefficient of Correlation and modified index of agreement. CanESM5, CAS-ESM2-0, UKES-M1-1-LL, HadGEM-GC31-LL, MPI-ESM1-2-HR, and GISS-E2-2-G were identified as the top performers. The Multi-Model Ensemble was created assembling these six GCMs through Random Forest (RFE), since it was found that it discriminates local under or overestimations in GCMs. RFE was used for short-term (2026-2050), medium-term (2051-2075), and long-term (2076-2100) projections under three emission scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Results indicate a projected decrease in annual rainfall in southern areas, accompanied by more notable declines in summer and autumn. On the contrary, the Alps, particularly the Austrian Alps, show resilience to summer stress, with some regions even showing increases in rainfall. Additionally, there is a noticeable north-south pattern in spring and winter. Finally, anomalies were compared against those reported by IPCC, detecting a potentially drier summer, spring and annual yield, and a wetter winter and autumn. The study provides valuable insights into GCM performance in the Euro-Med, offering a robust foundation for improved future rainfall projections and a reduction in associated uncertainties, crucial for climate change adaptation strategies in the European Mediterranean Region.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"158 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055262","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}
{"title":"Crust‐mantle decoupling in the Gakkel Ridge induced by strong heterogeneity of the asthenosphere","authors":"Yang Xu, Chuan-Zhou Liu, Yin-Zheng Lin, Bo-Da Liu","doi":"10.1007/s00410-025-02198-5","DOIUrl":"10.1007/s00410-025-02198-5","url":null,"abstract":"<div><p>Abyssal peridotites can provide complementary information on the compositional features of the asthenosphere, as the refractory mantle within the asthenosphere contributes little to the genesis of mid-ocean ridge basalts (MORB). Here we present major and trace elements of ~ 70 abyssal peridotites from the Sparsely Magmatic Zone (SMZ) and Eastern Volcanic Zone (EVZ) of the Gakkel Ridge, which are residues of the asthenosphere that have undergone < 15% partial melting. Their clinopyroxenes display LREE-depleted and LREE-flat patterns, the latter of which resulted from refertilization by quasi-instantaneous melts in the melting zone beneath the mid-ocean ridge. Compositions of the Gakkel peridotites are highly variable along the ridge axis, which cannot be attributed to the spatial variation of temperature of the asthenosphere. The estimated degrees of melting of the Gakkel abyssal peridotites are higher than the values inferred by seismic thickness of ocean crust along the SMZ and EVZ. This implies the Gakkel abyssal peridotites inherit ancient melting prior to their entering the Gakkel Ridge, which also causes the crust-mantle decoupling in compositions. Moreover, compositions of the Gakkel peridotites differs significantly from subduction-related peridotites. We suggest the asthenosphere beneath the Gakkel Ridge is highly heterogeneous in compositions, which is the culprit of crust-mantle geochemical decoupling. Enriched MORB erupted in the SMZ region were derived from small amounts of enriched components within the asthenosphere, which cannot be represented by the abyssal peridotites exposed in this region.</p></div>","PeriodicalId":526,"journal":{"name":"Contributions to Mineralogy and Petrology","volume":"180 2","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995582","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}