Pub Date : 2025-12-14DOI: 10.1016/j.geomorph.2025.110137
Shintaro Yamasaki
Landslides frequently occur in tectonically deformed mountain areas, where folding and faulting have altered rock mass conditions. Previous research has largely focused on the impacts of large-scale folds on rock mass quality and landslide occurrence; however, even smaller folds (mesoscopic- to microscopic-scale folds, hereafter MMFs) can markedly promote landslides when dense cleavage forms in conjunction with them. To clarify how MMFs and cleavage jointly control landslide distribution and failure, this study employed (1) an inventory of landslides to determine their spatial distribution and movement directions, (2) detailed outcrop surveys along roads and landslide sites to record the geometry of fold axial surfaces and cleavage, and (3) morphological analyses of rupture surfaces and open cracks at sites with recent landslide activity. The results indicate that areas with extensive MMFs experience more frequent landslides, and that open cracks and rupture surfaces can reach greater depths if formed by the combination of steep cleavage parallel or subparallel to the MMF axial surface and schistosity already steepened by folding. Such a crack network creates expanded pathways for rainwater and groundwater, making slopes more susceptible to landslides under repeated water pressure and stress changes during heavy rainfall or seismic shaking. In addition, these two-directional discontinuities arising from folds and cleavage are likely to be important factors in landslide prediction and risk evaluation in low-grade metamorphic mountains worldwide. The study's findings thus provide a reference for slope risk assessment in mountainous regions characterized by high-density folding and cleavage development.
{"title":"High-density fold–cleavage structures as a controlling factor of landslides: A case study in the southern Oboke area of the Shikoku Mountains, Japan","authors":"Shintaro Yamasaki","doi":"10.1016/j.geomorph.2025.110137","DOIUrl":"10.1016/j.geomorph.2025.110137","url":null,"abstract":"<div><div>Landslides frequently occur in tectonically deformed mountain areas, where folding and faulting have altered rock mass conditions. Previous research has largely focused on the impacts of large-scale folds on rock mass quality and landslide occurrence; however, even smaller folds (mesoscopic- to microscopic-scale folds, hereafter MMFs) can markedly promote landslides when dense cleavage forms in conjunction with them. To clarify how MMFs and cleavage jointly control landslide distribution and failure, this study employed (1) an inventory of landslides to determine their spatial distribution and movement directions, (2) detailed outcrop surveys along roads and landslide sites to record the geometry of fold axial surfaces and cleavage, and (3) morphological analyses of rupture surfaces and open cracks at sites with recent landslide activity. The results indicate that areas with extensive MMFs experience more frequent landslides, and that open cracks and rupture surfaces can reach greater depths if formed by the combination of steep cleavage parallel or subparallel to the MMF axial surface and schistosity already steepened by folding. Such a crack network creates expanded pathways for rainwater and groundwater, making slopes more susceptible to landslides under repeated water pressure and stress changes during heavy rainfall or seismic shaking. In addition, these two-directional discontinuities arising from folds and cleavage are likely to be important factors in landslide prediction and risk evaluation in low-grade metamorphic mountains worldwide. The study's findings thus provide a reference for slope risk assessment in mountainous regions characterized by high-density folding and cleavage development.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110137"},"PeriodicalIF":3.1,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798562","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}
Pub Date : 2025-12-13DOI: 10.1016/j.geomorph.2025.110136
Fangyi Yan , Haijia Wen , Yujie Li , Jiwei Hu , Peng Xie
Rockfalls occurring along the Yangtze River's reservoir banks pose a considerable threat to shipping safety, necessitating extensive spatial identification. Numerical analysis methods are often employed to assess rockfall stability, yet the inherent complexity of rock structures and the uncertainty of related parameters pose significant challenges in providing accurate inputs for numerical simulation models. Fortunately, the advent of high-precision DEM (Digital Elevation Model) models and advancements in artificial intelligence techniques now enable preliminary identification of potential rockfall locations based on topographic factors. In this study, the r.slopeunits method was employed to delineate slope units along the Yangtze River's reservoir banks, while the Scoops3D model was used to screen stable slope units. These stable units, together with known potential rockfall units, formed the dataset for machine learning. Unlike previous susceptibility assessment methods, this study focused on constructing the dataset using seven refined topographic factors, all derived exclusively from DEM data. The LightGBM algorithm was adopted for rockfall susceptibility prediction, with model validation conducted via 5-fold cross-validation and 100 random splits of the training and test sets (at a 7:3 ratio). The results indicated that slope standard deviation had the greatest impact on slope stability, with 87.6 % of rockfalls occurring in extremely high-risk areas. These findings underscore the importance of topographic factors in assessing rockfall susceptibility along the reservoir banks. Furthermore, the model achieves rockfall risk assessment using only DEM data, demonstrating strong generalization capability and providing extensive support for disaster prevention efforts.
{"title":"Rockfall susceptibility mapping from topography perspective combing slope units and physical model-based negative sample strategy in the Yangtze Three Gorges","authors":"Fangyi Yan , Haijia Wen , Yujie Li , Jiwei Hu , Peng Xie","doi":"10.1016/j.geomorph.2025.110136","DOIUrl":"10.1016/j.geomorph.2025.110136","url":null,"abstract":"<div><div>Rockfalls occurring along the Yangtze River's reservoir banks pose a considerable threat to shipping safety, necessitating extensive spatial identification. Numerical analysis methods are often employed to assess rockfall stability, yet the inherent complexity of rock structures and the uncertainty of related parameters pose significant challenges in providing accurate inputs for numerical simulation models. Fortunately, the advent of high-precision DEM (Digital Elevation Model) models and advancements in artificial intelligence techniques now enable preliminary identification of potential rockfall locations based on topographic factors. In this study, the r.slopeunits method was employed to delineate slope units along the Yangtze River's reservoir banks, while the Scoops3D model was used to screen stable slope units. These stable units, together with known potential rockfall units, formed the dataset for machine learning. Unlike previous susceptibility assessment methods, this study focused on constructing the dataset using seven refined topographic factors, all derived exclusively from DEM data. The LightGBM algorithm was adopted for rockfall susceptibility prediction, with model validation conducted via 5-fold cross-validation and 100 random splits of the training and test sets (at a 7:3 ratio). The results indicated that slope standard deviation had the greatest impact on slope stability, with 87.6 % of rockfalls occurring in extremely high-risk areas. These findings underscore the importance of topographic factors in assessing rockfall susceptibility along the reservoir banks. Furthermore, the model achieves rockfall risk assessment using only DEM data, demonstrating strong generalization capability and providing extensive support for disaster prevention efforts.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110136"},"PeriodicalIF":3.1,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798524","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}
Pub Date : 2025-12-12DOI: 10.1016/j.geomorph.2025.110135
Junjie Zou , Feng Shi , Honglin He , Zhigang Shao , Wenqiao Li , Yoshiki Shirahama , Zhanyu Wei , Jianhua Huang
The geometric structure of faults, especially normal faults in extensional regions, is often complex. In faulted depression basins, normal faults typically exhibit branching in both bedrock and sedimentary areas. While paleoearthquake history in sedimentary regions can be studied through the trenching method, this method is not applicable to bedrock faults. For bedrock faults, terrestrial Light Detection and Ranging (t-LiDAR) has become an effective tool for analyzing fault scarps. To fully evaluate fault activity, traditional methods should be combined with new techniques. In this study, we focus on the Yu-Guang Basin southern marginal fault (YBSM Fault) in the Shanxi Rift, China. Although previous studies have investigated the fault, the co-seismic slip history and seismogenic potential remain unclear. We analyzed the Nanmazhuang (NMZ) bedrock fault surface using quantitative morphological analysis, aerial, and field surveys, identifying two seismic events with co-seismic dip slips of 3.1 m and 3.4 m. Empirical formulas suggest the bedrock branch fault can produce earthquakes with magnitudes greater than 7.5. At the Xizhuangtou (XZT) site, a Holocene fault was found with a cumulative displacement of 7 m and a throw rate of 0.7–0.85 mm/yr. A paleoearthquake with a co-seismic slip of 0.4–0.5 m occurred after 23.4–22.5 ka in sediments. The complete paleoearthquake sequence indicates an average recurrence interval of ~6.8 ka and an average elapsed time of ~8.5 ka for the sedimentary fault branch. The study integrates data from both fault branches, demonstrating that both are potential seismic risk sources. Considering the bedrock fault's large coseismic slip and capacity for M > 7.5 earthquakes, as well as the longer elapsed time, attention to seismic hazards on the YBSM Fault is critical.
{"title":"Late-Quaternary activity of parallel normal faults along the southern margin of the Yuguang Basin in the Shanxi Rift, China and its seismogeological implications","authors":"Junjie Zou , Feng Shi , Honglin He , Zhigang Shao , Wenqiao Li , Yoshiki Shirahama , Zhanyu Wei , Jianhua Huang","doi":"10.1016/j.geomorph.2025.110135","DOIUrl":"10.1016/j.geomorph.2025.110135","url":null,"abstract":"<div><div>The geometric structure of faults, especially normal faults in extensional regions, is often complex. In faulted depression basins, normal faults typically exhibit branching in both bedrock and sedimentary areas. While paleoearthquake history in sedimentary regions can be studied through the trenching method, this method is not applicable to bedrock faults. For bedrock faults, terrestrial Light Detection and Ranging (t-LiDAR) has become an effective tool for analyzing fault scarps. To fully evaluate fault activity, traditional methods should be combined with new techniques. In this study, we focus on the Yu-Guang Basin southern marginal fault (YBSM Fault) in the Shanxi Rift, China. Although previous studies have investigated the fault, the co-seismic slip history and seismogenic potential remain unclear. We analyzed the Nanmazhuang (NMZ) bedrock fault surface using quantitative morphological analysis, aerial, and field surveys, identifying two seismic events with co-seismic dip slips of 3.1 m and 3.4 m. Empirical formulas suggest the bedrock branch fault can produce earthquakes with magnitudes greater than 7.5. At the Xizhuangtou (XZT) site, a Holocene fault was found with a cumulative displacement of 7 m and a throw rate of 0.7–0.85 mm/yr. A paleoearthquake with a co-seismic slip of 0.4–0.5 m occurred after 23.4–22.5 ka in sediments. The complete paleoearthquake sequence indicates an average recurrence interval of ~6.8 ka and an average elapsed time of ~8.5 ka for the sedimentary fault branch. The study integrates data from both fault branches, demonstrating that both are potential seismic risk sources. Considering the bedrock fault's large coseismic slip and capacity for M > 7.5 earthquakes, as well as the longer elapsed time, attention to seismic hazards on the YBSM Fault is critical.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110135"},"PeriodicalIF":3.1,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798565","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}
Pub Date : 2025-12-12DOI: 10.1016/j.geomorph.2025.110134
Jacek Szczygieł , Jerzy Zasadni , Piotr Kłapyta , Marta Woszczycka , Krzysztof Gaidzik , Maciej Mendecki , Artur Sobczyk , Christoph Grützner
Areas with low deformation rates, such as continental interiors or mature orogens, may represent significant seismic hazard zones, albeit still insufficiently recognized. Relatively low-magnitude earthquakes occurring in such regions pose challenges for paleoseismology, despite occasional documented surface fault ruptures. This study focuses on a scarp located in the Podhale Basin (Central Western Carpathians) that deviates from empirical displacement-length scaling relationships. Despite its relatively short length of only 3 km, the scarp, measuring 4 m in height, presents several indications of its tectonic origin, yet to some extent scarp height could have been exaggerated by creep of weathered clays. Geophysical GPR and ERT surveys revealed a vertical discontinuity directly beneath the scarp. Moreover, we identified distinct features interpreted as a fault zone in a trench across the scarp. Lacking material suitable for dating, we estimated the age of the fault scarp at 10–50 ka using simple linear diffusion modeling. However, this result requires caution due to assumptions like scarp formation from a single event. Yet, the consistency of the estimated age with the superposition of the scarp relative to the morphology and weathered covers from the last glaciation is noteworthy. Furthermore, morphological and geological mapping suggests dextral oblique kinematics of the studied fault. The prevailing trend of NE (NNE) compression across the Podhale and Orava basins and the Tatra Mountains aligns the dextral Brzegi fault with the broader Alpine-Carpathian geodynamic framework. The Brzegi fault, as part of the broader Białka fault zone, provides evidence of far-field effects, serving as an NNW-striking dextral antithetic fault to major sinistral NE-SW striking faults. The recognized pattern indicates the continued post-Miocene Alpine extrusion towards the Carpathians.
{"title":"The curious case of a short fault scarp in the podhale basin: Implications for late pleistocene geodynamics of the central western carpathians","authors":"Jacek Szczygieł , Jerzy Zasadni , Piotr Kłapyta , Marta Woszczycka , Krzysztof Gaidzik , Maciej Mendecki , Artur Sobczyk , Christoph Grützner","doi":"10.1016/j.geomorph.2025.110134","DOIUrl":"10.1016/j.geomorph.2025.110134","url":null,"abstract":"<div><div>Areas with low deformation rates, such as continental interiors or mature orogens, may represent significant seismic hazard zones, albeit still insufficiently recognized. Relatively low-magnitude earthquakes occurring in such regions pose challenges for paleoseismology, despite occasional documented surface fault ruptures. This study focuses on a scarp located in the Podhale Basin (Central Western Carpathians) that deviates from empirical displacement-length scaling relationships. Despite its relatively short length of only 3 km, the scarp, measuring 4 m in height, presents several indications of its tectonic origin, yet to some extent scarp height could have been exaggerated by creep of weathered clays. Geophysical GPR and ERT surveys revealed a vertical discontinuity directly beneath the scarp. Moreover, we identified distinct features interpreted as a fault zone in a trench across the scarp. Lacking material suitable for dating, we estimated the age of the fault scarp at 10–50 ka using simple linear diffusion modeling. However, this result requires caution due to assumptions like scarp formation from a single event. Yet, the consistency of the estimated age with the superposition of the scarp relative to the morphology and weathered covers from the last glaciation is noteworthy. Furthermore, morphological and geological mapping suggests dextral oblique kinematics of the studied fault. The prevailing trend of NE (NNE) compression across the Podhale and Orava basins and the Tatra Mountains aligns the dextral Brzegi fault with the broader Alpine-Carpathian geodynamic framework. The Brzegi fault, as part of the broader Białka fault zone, provides evidence of far-field effects, serving as an NNW-striking dextral antithetic fault to major sinistral NE-SW striking faults. The recognized pattern indicates the continued post-Miocene Alpine extrusion towards the Carpathians.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110134"},"PeriodicalIF":3.1,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841290","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}
Pub Date : 2025-12-10DOI: 10.1016/j.geomorph.2025.110126
Philippe Audra , Luca Pisani , Marco Antonellini , Francisco Hilario R. Bezerra , Augusto S. Auler , Vincenzo La Bruna , Giovanni Bertotti , Fabrizio Balsamo , Cayo C.C. Pontes , Rebeca S. Lima , Marjan Temovski , Xianfeng Wang , Jo De Waele
Ioiô Cave is a 4.7 km long maze cave in the southern tip of the Irecê Basin (Bahìa, Brazil), and although still actively forming today, it hosts signs of a long speleogenetic history. Deep rising hydrothermal fluids weathered the carbonates, creating dark ghost-rocks and quartz and dolomite veins, mainly in the anticlinal hinges and below the siliciclastic seals. This silicification, although not directly dated, is probably associated with the end of the Brasiliano-age tectono-thermal activity (Lower Cambrian) based on isotopic and trace element data and regional tectonic correlations. Since the Plio-Quaternary, the progressive exhumation of the carbonate reservoir increasingly favored the introduction of meteoric oxygen-rich water from the surface, causing sulfide oxidation at shallow aquifer depth. The CO2 produced by Sulfuric Acid Speleogenesis (SAS) rose along fractures and degassed at shallow depth, producing carbonic speleogenesis close to the water table. This carbonic speleogenesis, probably still active, produced a maze network, by horizontal diffusion of aggressive fluids from the feeders. Surface breaching increased air flow activating degassing and supersaturation of the basins, with deposition of subaqueous calcite shelves, carved with bubble trails resulting from CO2 degassing related to still-ongoing pyrite oxidation (localized SAS).
{"title":"Deep-seated cave inception and shallow sulfuric acid maze cave genesis in Southern Irecê Basin, São Francisco Craton (Brazil)","authors":"Philippe Audra , Luca Pisani , Marco Antonellini , Francisco Hilario R. Bezerra , Augusto S. Auler , Vincenzo La Bruna , Giovanni Bertotti , Fabrizio Balsamo , Cayo C.C. Pontes , Rebeca S. Lima , Marjan Temovski , Xianfeng Wang , Jo De Waele","doi":"10.1016/j.geomorph.2025.110126","DOIUrl":"10.1016/j.geomorph.2025.110126","url":null,"abstract":"<div><div>Ioiô Cave is a 4.7 km long maze cave in the southern tip of the Irecê Basin (Bahìa, Brazil), and although still actively forming today, it hosts signs of a long speleogenetic history. Deep rising hydrothermal fluids weathered the carbonates, creating dark ghost-rocks and quartz and dolomite veins, mainly in the anticlinal hinges and below the siliciclastic seals. This silicification, although not directly dated, is probably associated with the end of the Brasiliano-age tectono-thermal activity (Lower Cambrian) based on isotopic and trace element data and regional tectonic correlations. Since the Plio-Quaternary, the progressive exhumation of the carbonate reservoir increasingly favored the introduction of meteoric oxygen-rich water from the surface, causing sulfide oxidation at shallow aquifer depth. The CO<sub>2</sub> produced by Sulfuric Acid Speleogenesis (SAS) rose along fractures and degassed at shallow depth, producing carbonic speleogenesis close to the water table. This carbonic speleogenesis, probably still active, produced a maze network, by horizontal diffusion of aggressive fluids from the feeders. Surface breaching increased air flow activating degassing and supersaturation of the basins, with deposition of subaqueous calcite shelves, carved with bubble trails resulting from CO<sub>2</sub> degassing related to still-ongoing pyrite oxidation (localized SAS).</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110126"},"PeriodicalIF":3.1,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798560","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}
Pub Date : 2025-12-08DOI: 10.1016/j.geomorph.2025.110127
Yehui Wang , Yuanyun Xie , Lei Sun , Zhenyu Wei , Haodong Qi , Haijin Liu , Peng Wu
Terrestrial sedimentary systems, as faithful records of the coupling between tectonic and climatic processes, not only reflect the evolutionary history of surface processes but also profoundly influence regional and even global environmental changes through complex feedback mechanisms. The Hailar Basin in Northeast China, as a Quaternary terrestrial basin in an arid-semi-arid region, holds significant importance for understanding the East Asian dust system and response mechanisms to the tectonic and climate through clarifying its geomorphic evolution and aeolian surface processes. The Quaternary fillings in the Hailar Basin, NE China, consist mainly of the Early Pleistocene Baitushan Formation, the Late Pleistocene Hailar Formation, and the Holocene aeolian sand covers. In this study, we present the first detrital zircon UPb geochronological data for the infilling and major river sediments in the Hailar Basin. This study aims to reveal changes in the provenance and surface processes of the Hailar Basin since the Early Pleistocene through zircon age comparison, quantitative results of inverse Monte Carlo, and multidimensional scaling (MDS). By integrating the evolution of sedimentary facies and the depositional ages of various strata, the research further explores the dominant driving mechanisms behind these changes, providing an important reference for sedimentary research on terrestrial basins in Northeast Asia. The results indicate that tectonics and climate jointly influenced the changes in surface processes, including provenance shifts and the formation of the modern Hulunbuir Sandy Land (HLSL). With the uplift of the Great Xing'an Range during the Early Pleistocene (∼1.4 Ma), a significant amount of coarse-grained clastics, such as gravels and sands, were transported by major rivers into the basin, resulting in the formation of the Baitushan Formation sediments (with ∼98 % of the material derived from the Great Xing'an Range). At this stage, climate may exert a slight potential influence on the intensity of source erosion and the rate of sedimentation. In the Late Pleistocene, the uplift of the Great Xing'an Range ceased, leading to the accumulation of fine-grained sediments of the Hailar Formation within the basin and the concurrent development of fluvial-lacustrine landscapes. Meanwhile, the uplift of the Central Mongolia Block (C. MG) and the intensification of the East Asian Winter Monsoon (EAWM) resulted in the deposition of a substantial amount of sandy material (25.19–48.5 %) from the C. MG into the basin. Subsequently, the warmer and wetter regional climate increased precipitation and fluvial erosion, leading to the continuous reworking of detrital materials from the C. MG, the basin basement, and the Hailar Formation through the interplay of northwesterly winds and fluvial processes. Ultimately, this process drove the formation of the modern aeolian sands in the HLSL.
{"title":"Provenance changes of Quaternary fillings and geomorphic processes of modern aeolian sand formation in the Hailar Basin, NE China","authors":"Yehui Wang , Yuanyun Xie , Lei Sun , Zhenyu Wei , Haodong Qi , Haijin Liu , Peng Wu","doi":"10.1016/j.geomorph.2025.110127","DOIUrl":"10.1016/j.geomorph.2025.110127","url":null,"abstract":"<div><div>Terrestrial sedimentary systems, as faithful records of the coupling between tectonic and climatic processes, not only reflect the evolutionary history of surface processes but also profoundly influence regional and even global environmental changes through complex feedback mechanisms. The Hailar Basin in Northeast China, as a Quaternary terrestrial basin in an arid-semi-arid region, holds significant importance for understanding the East Asian dust system and response mechanisms to the tectonic and climate through clarifying its geomorphic evolution and aeolian surface processes. The Quaternary fillings in the Hailar Basin, NE China, consist mainly of the Early Pleistocene Baitushan Formation, the Late Pleistocene Hailar Formation, and the Holocene aeolian sand covers. In this study, we present the first detrital zircon U<img>Pb geochronological data for the infilling and major river sediments in the Hailar Basin. This study aims to reveal changes in the provenance and surface processes of the Hailar Basin since the Early Pleistocene through zircon age comparison, quantitative results of inverse Monte Carlo, and multidimensional scaling (MDS). By integrating the evolution of sedimentary facies and the depositional ages of various strata, the research further explores the dominant driving mechanisms behind these changes, providing an important reference for sedimentary research on terrestrial basins in Northeast Asia. The results indicate that tectonics and climate jointly influenced the changes in surface processes, including provenance shifts and the formation of the modern Hulunbuir Sandy Land (HLSL). With the uplift of the Great Xing'an Range during the Early Pleistocene (∼1.4 Ma), a significant amount of coarse-grained clastics, such as gravels and sands, were transported by major rivers into the basin, resulting in the formation of the Baitushan Formation sediments (with ∼98 % of the material derived from the Great Xing'an Range). At this stage, climate may exert a slight potential influence on the intensity of source erosion and the rate of sedimentation. In the Late Pleistocene, the uplift of the Great Xing'an Range ceased, leading to the accumulation of fine-grained sediments of the Hailar Formation within the basin and the concurrent development of fluvial-lacustrine landscapes. Meanwhile, the uplift of the Central Mongolia Block (C. MG) and the intensification of the East Asian Winter Monsoon (EAWM) resulted in the deposition of a substantial amount of sandy material (25.19–48.5 %) from the C. MG into the basin. Subsequently, the warmer and wetter regional climate increased precipitation and fluvial erosion, leading to the continuous reworking of detrital materials from the C. MG, the basin basement, and the Hailar Formation through the interplay of northwesterly winds and fluvial processes. Ultimately, this process drove the formation of the modern aeolian sands in the HLSL.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110127"},"PeriodicalIF":3.1,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798525","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}
Pub Date : 2025-12-08DOI: 10.1016/j.geomorph.2025.110132
M. Vandana, J. Amal Dev, J.K. Tomson, Srikumar Chattopadhyay
Drainage basin reorganisation is a fundamental earth surface process with significant implications for landscape evolution, sediment routing, and hydrological regimes. In this study, we investigate the Kallada and Ithikkara rivers in the southern Western Ghats to constrain the timing, mechanisms, and geomorphic consequences of river capture in their upper catchments. Morphometric and sedimentary provenance analyses indicate that the upper Kallada and Ithikkara basins were once part of a single, integrated drainage network. Chi (χ) analysis further reveals that following the river capture event, the Ithikkara basin experienced a substantial reduction in upper catchment area. The chi map geometry suggests that the upper Kallada basin, presently located upstream of a pronounced channel elbow, may originally have drained through the present Ithikkara channel before being captured by the Kallada river. Detrital zircon UPb geochronology from sediments of both rivers exhibits remarkably similar age spectra, with prominent peaks at ~2500 Ma, ~1900 Ma, ~1000 Ma, ~750 Ma, and ~550 Ma, indicating derivation from a shared sediment source. Integration of geomorphic metrics with provenance data supports a scenario in which tectonic or geomorphic processes separated the upper Kallada basin from the main Ithikkara drainage system, resulting in reorganisation of the regional river network. These findings demonstrate the value of combining quantitative geomorphic approaches with sedimentary geochronology to reconstruct past drainage evolution, even in tectonically stable regions, and provide new insights into the links between river capture, sediment provenance, and landscape dynamics in the southern Western Ghats.
{"title":"Drainage basin reorganisation in Trivandrum block, Southern Western Ghats, India","authors":"M. Vandana, J. Amal Dev, J.K. Tomson, Srikumar Chattopadhyay","doi":"10.1016/j.geomorph.2025.110132","DOIUrl":"10.1016/j.geomorph.2025.110132","url":null,"abstract":"<div><div>Drainage basin reorganisation is a fundamental earth surface process with significant implications for landscape evolution, sediment routing, and hydrological regimes. In this study, we investigate the Kallada and Ithikkara rivers in the southern Western Ghats to constrain the timing, mechanisms, and geomorphic consequences of river capture in their upper catchments. Morphometric and sedimentary provenance analyses indicate that the upper Kallada and Ithikkara basins were once part of a single, integrated drainage network. Chi (χ) analysis further reveals that following the river capture event, the Ithikkara basin experienced a substantial reduction in upper catchment area. The chi map geometry suggests that the upper Kallada basin, presently located upstream of a pronounced channel elbow, may originally have drained through the present Ithikkara channel before being captured by the Kallada river. Detrital zircon U<img>Pb geochronology from sediments of both rivers exhibits remarkably similar age spectra, with prominent peaks at ~2500 Ma, ~1900 Ma, ~1000 Ma, ~750 Ma, and ~550 Ma, indicating derivation from a shared sediment source. Integration of geomorphic metrics with provenance data supports a scenario in which tectonic or geomorphic processes separated the upper Kallada basin from the main Ithikkara drainage system, resulting in reorganisation of the regional river network. These findings demonstrate the value of combining quantitative geomorphic approaches with sedimentary geochronology to reconstruct past drainage evolution, even in tectonically stable regions, and provide new insights into the links between river capture, sediment provenance, and landscape dynamics in the southern Western Ghats.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110132"},"PeriodicalIF":3.1,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798564","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}
Pub Date : 2025-12-08DOI: 10.1016/j.geomorph.2025.110131
Sharon Pittau , Vittoria Scorpio
The post-1950s evolutionary trajectories of the Taro and Ceno rivers (Northern Apennines, Italy) were investigated, focusing on the correlation between channel adjustments and sediment alterations. The specific aims were to: i) highlight similarities and dissimilarities between the evolutionary trajectories of the two rivers; ii) assess the role of sediment connectivity decrease caused by land use changes along the hillslopes, and iii) evaluate the impact of gravel mining.
Changes in active channel width and bed level were quantified using multi-temporal orthophotos (1954–2020) and topographical cross-sections. Land use dynamics were reconstructed through multi-temporal land cover maps, and changes in structural sediment connectivity were assessed by applying the Index of Connectivity (IC). Evolution of landslide-prone areas was analysed to estimate changes in sediment supply, and the influence of anthropogenic activities was also considered through mapping gravel mining areas and in-channel works.
Results showed progressive afforestation, after the 1950s in the Ceno and after the 1970s in the Taro basin, with decreases in landslide-prone areas and IC. Hillslope stabilization caused a decrease in sediment supply to both channels, with subsequent channel narrowing and bed incision (−50 % and −3.3 m in the Taro and −38 % and −2.5 m in the Ceno, respectively). More intense morphological changes in the Taro, especially between 1954 and 1976, were linked to the intense gravel mining activity, completely absent along the Ceno. The combined effects of catchment-scale afforestation and reach-scale gravel extraction therefore played a key role in shaping the dissimilarities in the evolutionary trajectories between the two rivers.
{"title":"Effects of sediment connectivity changes on channel evolutionary trajectory: the case study of the Taro and Ceno rivers in the Northern Apennines (Italy)","authors":"Sharon Pittau , Vittoria Scorpio","doi":"10.1016/j.geomorph.2025.110131","DOIUrl":"10.1016/j.geomorph.2025.110131","url":null,"abstract":"<div><div>The post-1950s evolutionary trajectories of the Taro and Ceno rivers (Northern Apennines, Italy) were investigated, focusing on the correlation between channel adjustments and sediment alterations. The specific aims were to: i) highlight similarities and dissimilarities between the evolutionary trajectories of the two rivers; ii) assess the role of sediment connectivity decrease caused by land use changes along the hillslopes, and iii) evaluate the impact of gravel mining.</div><div>Changes in active channel width and bed level were quantified using multi-temporal orthophotos (1954–2020) and topographical cross-sections. Land use dynamics were reconstructed through multi-temporal land cover maps, and changes in structural sediment connectivity were assessed by applying the Index of Connectivity (IC). Evolution of landslide-prone areas was analysed to estimate changes in sediment supply, and the influence of anthropogenic activities was also considered through mapping gravel mining areas and in-channel works.</div><div>Results showed progressive afforestation, after the 1950s in the Ceno and after the 1970s in the Taro basin, with decreases in landslide-prone areas and IC. Hillslope stabilization caused a decrease in sediment supply to both channels, with subsequent channel narrowing and bed incision (−50 % and −3.3 m in the Taro and −38 % and −2.5 m in the Ceno, respectively). More intense morphological changes in the Taro, especially between 1954 and 1976, were linked to the intense gravel mining activity, completely absent along the Ceno. The combined effects of catchment-scale afforestation and reach-scale gravel extraction therefore played a key role in shaping the dissimilarities in the evolutionary trajectories between the two rivers.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110131"},"PeriodicalIF":3.1,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798561","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}
Pub Date : 2025-12-08DOI: 10.1016/j.geomorph.2025.110133
Benhong Guo , Jiechang Gao , Zhenghao Qin , Fuhang Niu , Yindi Wang , Tingjiang Peng , Shanpin Liu , Chengying Liu , Junsheng Nie
The fluvial terrace sequences in the northeastern Tibetan Plateau indicate that the modern Yellow River primarily originated in the Lanzhou Basin around 1.8 Ma and subsequently extended into the interior of the Tibetan Plateau through headward erosion. However, the evolutionary history and driving mechanisms of the paleo-Yellow River during the Pliocene-Pleistocene, prior to the formation of the modern Yellow River system, remain unclear despite its establishment by ~3.6 Ma. In this study, we present the new results of magnetic susceptibility and combined with previous sedimentological analyses and detrital zircon UPb ages of fluvial sequences spanning the interval of ~3.6–2.2 Ma in the Lanzhou Basin, in the northeastern Tibetan Plateau. Our results reveal a rapid increase in the sediment supply into the Lanzhou Basin from the northeastern Tibetan Plateau at ~3 Ma, signaling an expansion of the paleo-Yellow River drainage system at this time. This Late Pliocene drainage system expansion coincides with the intensification of the East Asian summer monsoon, which may reflect interactions between the evolution of the paleo-Yellow River and climate change.
{"title":"Northeastern Tibetan Plateau paleo-Yellow River drainage expansion at ~3 Ma linked to the East Asian summer monsoon intensification","authors":"Benhong Guo , Jiechang Gao , Zhenghao Qin , Fuhang Niu , Yindi Wang , Tingjiang Peng , Shanpin Liu , Chengying Liu , Junsheng Nie","doi":"10.1016/j.geomorph.2025.110133","DOIUrl":"10.1016/j.geomorph.2025.110133","url":null,"abstract":"<div><div>The fluvial terrace sequences in the northeastern Tibetan Plateau indicate that the modern Yellow River primarily originated in the Lanzhou Basin around 1.8 Ma and subsequently extended into the interior of the Tibetan Plateau through headward erosion. However, the evolutionary history and driving mechanisms of the paleo-Yellow River during the Pliocene-Pleistocene, prior to the formation of the modern Yellow River system, remain unclear despite its establishment by ~3.6 Ma. In this study, we present the new results of magnetic susceptibility and combined with previous sedimentological analyses and detrital zircon U<img>Pb ages of fluvial sequences spanning the interval of ~3.6–2.2 Ma in the Lanzhou Basin, in the northeastern Tibetan Plateau. Our results reveal a rapid increase in the sediment supply into the Lanzhou Basin from the northeastern Tibetan Plateau at ~3 Ma, signaling an expansion of the paleo-Yellow River drainage system at this time. This Late Pliocene drainage system expansion coincides with the intensification of the East Asian summer monsoon, which may reflect interactions between the evolution of the paleo-Yellow River and climate change.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110133"},"PeriodicalIF":3.1,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145750298","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}
Pub Date : 2025-12-07DOI: 10.1016/j.geomorph.2025.110118
Daria Khashchevskaya , Jason M. Dortch , Lewis A. Owen , Paula Figueiredo
The setting of weak shales underlying heavily fractured sandstone caprock, coupled with the wet environmental conditions along the valley slopes of the Rough River Basin in north-central Kentucky, has led to massive rockfalls composed of clusters of sandstone boulders. However, the exact mechanisms of cliff retreat and sediment accumulation due to mass movement in that region remained unclear. In addition, the frequency and timing of these mass movement events are uncertain. To better understand mass movement mechanisms, we used the Schmidt Hammer exposure dating (SHED) technique and terrestrial cosmogenic nuclide dating on two sites in the Rough River basin, “Home Tucker” and “Linda Paul.” The results suggest that the degradation mechanism of sandstone cliffs by mass movement varies due to local geology and climate change. The Home Tucker site exhibits boulder accumulation through rockfall during the Early Holocene (10.6 ± 1.0 to 43.9 ± 3.0 ka), precluding the estimation of a cliff retreat rate. In contrast, the Linda Paul site exhibits block sliding and toppling, with detachment events spanning from 21 ± 1.6 to 66.8 ± 5.4 ka, and an estimated cliff retreat rate of 0.17 ± 0.09 mm/yr for Home Tucker site and 0.22 ± 0.1 mm/yr for the Linda Paul site. These findings suggest that detachment events occurred more frequently during the last glacial maximum, likely due to freeze-thaw processes or rapid climate change. With only one boulder dated to the Holocene, warming and a relatively stable climate during the Holocene have likely slowed cliff degradation. Attempts to develop a reliable SHED calibration curve were hindered by no correlation (r2 = 0.1) between 10Be age and SHED rebound measurement. This lack of correlation is likely due to variable vegetation cover, moisture inconsistencies, temporally non-linear and spatially heterogeneous weathering of quartz arenite, inheritance of weathering from before rock fall, and bed-dependent variations in strength.
{"title":"Using paired Schmidt Hammer and terrestrial cosmogenic surface exposure dating to study the timing and style of rockfalls in the Rough River Basin, Kentucky: Results, constraints, and possible mechanisms","authors":"Daria Khashchevskaya , Jason M. Dortch , Lewis A. Owen , Paula Figueiredo","doi":"10.1016/j.geomorph.2025.110118","DOIUrl":"10.1016/j.geomorph.2025.110118","url":null,"abstract":"<div><div>The setting of weak shales underlying heavily fractured sandstone caprock, coupled with the wet environmental conditions along the valley slopes of the Rough River Basin in north-central Kentucky, has led to massive rockfalls composed of clusters of sandstone boulders. However, the exact mechanisms of cliff retreat and sediment accumulation due to mass movement in that region remained unclear. In addition, the frequency and timing of these mass movement events are uncertain. To better understand mass movement mechanisms, we used the Schmidt Hammer exposure dating (SHED) technique and terrestrial cosmogenic nuclide dating on two sites in the Rough River basin, “Home Tucker” and “Linda Paul.” The results suggest that the degradation mechanism of sandstone cliffs by mass movement varies due to local geology and climate change. The Home Tucker site exhibits boulder accumulation through rockfall during the Early Holocene (10.6 ± 1.0 to 43.9 ± 3.0 ka), precluding the estimation of a cliff retreat rate. In contrast, the Linda Paul site exhibits block sliding and toppling, with detachment events spanning from 21 ± 1.6 to 66.8 ± 5.4 ka, and an estimated cliff retreat rate of 0.17 ± 0.09 mm/yr for Home Tucker site and 0.22 ± 0.1 mm/yr for the Linda Paul site. These findings suggest that detachment events occurred more frequently during the last glacial maximum, likely due to freeze-thaw processes or rapid climate change. With only one boulder dated to the Holocene, warming and a relatively stable climate during the Holocene have likely slowed cliff degradation. Attempts to develop a reliable SHED calibration curve were hindered by no correlation (r<sup>2</sup> = 0.1) between <sup>10</sup>Be age and SHED rebound measurement. This lack of correlation is likely due to variable vegetation cover, moisture inconsistencies, temporally non-linear and spatially heterogeneous weathering of quartz arenite, inheritance of weathering from before rock fall, and bed-dependent variations in strength.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"495 ","pages":"Article 110118"},"PeriodicalIF":3.1,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145750300","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}
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