Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107464
Yi Wu , Guanqiang Cai , Shun Li , Shixun Wang , Shuqing Fu , Yulin Han , Shichen Tao
Understanding past climate changes during the Holocene epoch, as recorded in continental shelf sediments, is crucial for reconstructing past climate patterns, sea-level fluctuations, and the influence of human activities. To explore Holocene environmental transitions in the northern South China Sea, we analyzed the sedimentary magnetic properties of the continental shelf east of Hainan Island. Our measurements revealed two significant transitions in magnetic mineral composition and grain size: around 7.6 ka and near 2 ka. The early transition around 7.6 ka is attributed to eustatic sea-level changes that altered coastal erosion, fluvial input, and sediment transportation due to the region's shallow shelf dynamics. Conversely, the recent transition near 2 ka is primarily due to the strengthened Atlantic Meridional Overturning Circulation, which influenced the East Asian monsoon regime. This later period coincides with intensified anthropogenic agricultural activities over the last ca. 2 kyr, highlighting interactions between natural and early human intervention. Between these transitions, from ca. 7.6 ka to ca. 2 ka, the magnetic proxy data suggest relatively stable environmental conditions resembling an event similar to a Holocene climatic optimum. This interval is characterized by consistent sedimentary magnetic properties, indicating a period of climatic stability under the monsoonal climate regime.
{"title":"Characterizing Holocene environmental transitions using magnetic properties of sediments from the continental shelf of the northern South China Sea","authors":"Yi Wu , Guanqiang Cai , Shun Li , Shixun Wang , Shuqing Fu , Yulin Han , Shichen Tao","doi":"10.1016/j.margeo.2024.107464","DOIUrl":"10.1016/j.margeo.2024.107464","url":null,"abstract":"<div><div>Understanding past climate changes during the Holocene epoch, as recorded in continental shelf sediments, is crucial for reconstructing past climate patterns, sea-level fluctuations, and the influence of human activities. To explore Holocene environmental transitions in the northern South China Sea, we analyzed the sedimentary magnetic properties of the continental shelf east of Hainan Island. Our measurements revealed two significant transitions in magnetic mineral composition and grain size: around 7.6 ka and near 2 ka. The early transition around 7.6 ka is attributed to eustatic sea-level changes that altered coastal erosion, fluvial input, and sediment transportation due to the region's shallow shelf dynamics. Conversely, the recent transition near 2 ka is primarily due to the strengthened Atlantic Meridional Overturning Circulation, which influenced the East Asian monsoon regime. This later period coincides with intensified anthropogenic agricultural activities over the last ca. 2 kyr, highlighting interactions between natural and early human intervention. Between these transitions, from ca. 7.6 ka to ca. 2 ka, the magnetic proxy data suggest relatively stable environmental conditions resembling an event similar to a Holocene climatic optimum. This interval is characterized by consistent sedimentary magnetic properties, indicating a period of climatic stability under the monsoonal climate regime.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107464"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107470
Debaleena Majumdar, H.N. Bhattacharya
The coastal zones of the Andaman Islands in the Bay of Bengal experienced the severe impact of an earthquake-generated tsunami on 26 December 2004. This study, conducted in 2023 investigates the sedimentary attributes of tsunami deposits found in trench and pit sections across three beaches: Bada Balu, Collinpur, and Mayabunder. The identified tsunami deposits include matrix-supported gravelly sand, massive sand, matrix-supported gravelly organic mud, normally graded to massive sand, and large bouldery gravel facies types. Bipartite flows, characterized by lower debris flows and upper turbidity currents generated after flow separation are responsible for the formation of gravelly mud or gravelly sand and sand couplets. Massive sand drapes over erosional surfaces are attributed to the waning phases of sand-laden tsunami run-up, while large bouldery gravel spreads, featuring rounded boulders, represent traction carpet deposits sourced from emerged coral reefs. The extreme variation in sediment composition and texture reveals that the strength of the tsunami waves and their propagation directions varied significantly across different coastal zones, largely influenced by coastal morphology. The distinct sedimentary structures of the studied 2004 earthquake-generated tsunami will serve as a valuable tool for interpreting tsunami deposits in the ancient record. Furthermore, the diagnostic criteria established in this study can be applied to distinguish between tsunami and cyclonic storm deposits.
{"title":"Event beds in Andaman beach sediments – records of 2004 Tsunami","authors":"Debaleena Majumdar, H.N. Bhattacharya","doi":"10.1016/j.margeo.2024.107470","DOIUrl":"10.1016/j.margeo.2024.107470","url":null,"abstract":"<div><div>The coastal zones of the Andaman Islands in the Bay of Bengal experienced the severe impact of an earthquake-generated tsunami on 26 December 2004. This study, conducted in 2023 investigates the sedimentary attributes of tsunami deposits found in trench and pit sections across three beaches: Bada Balu, Collinpur, and Mayabunder. The identified tsunami deposits include matrix-supported gravelly sand, massive sand, matrix-supported gravelly organic mud, normally graded to massive sand, and large bouldery gravel facies types. Bipartite flows, characterized by lower debris flows and upper turbidity currents generated after flow separation are responsible for the formation of gravelly mud or gravelly sand and sand couplets. Massive sand drapes over erosional surfaces are attributed to the waning phases of sand-laden tsunami run-up, while large bouldery gravel spreads, featuring rounded boulders, represent traction carpet deposits sourced from emerged coral reefs. The extreme variation in sediment composition and texture reveals that the strength of the tsunami waves and their propagation directions varied significantly across different coastal zones, largely influenced by coastal morphology. The distinct sedimentary structures of the studied 2004 earthquake-generated tsunami will serve as a valuable tool for interpreting tsunami deposits in the ancient record. Furthermore, the diagnostic criteria established in this study can be applied to distinguish between tsunami and cyclonic storm deposits.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107470"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2025.107476
José I. Isola , Fermín I. Palma , Sebastían Y. Principi , Graziella Bozzano , Ornella Silvestri , Juan P. Ormazabal , Alejandro A. Tassone
This study integrates a novel multi-beam bathymetry and high-resolution sub-bottom seismic database with previous works, to investigate a Late Quaternary Mixed (turbidite-contourite) Depositional System (MDS) related to a major submarine canyon system located on the Patagonian Continental Margin (PCM) between water depths of 1500 and 4000 m.
The studied MDS exhibits unique and unusual features, including the along-slope deviation of three submarine canyons, large-mounded drifts (>100 ms TWT) forming downstream of canyons, and small patchy drifts (a few tens ms TWT) accumulating in canyon-free slope areas. The genesis of these features is explained by a temporal substitution from contourite to mixed settings and different styles of interaction between along-slope and across-slope processes.
The along-slope deviation of the canyons is associated with the temporal substitution of contourite processes dominated period to the establishment of a MDS, marked by increased down-slope activity inferred to have occurred after the Mid-Pleistocene Transition (MPT). The fossil mounded morphologies developed during the dominant contourite period (pre MPT) acted as barriers to the subsequent submarine canyons formed during the increased down-slope activity period (post MPT), causing them to deviate by 90° along the slope.
After the MPT, spatial intercalation and interactions between along and across slope processes produced patchy and mounded drifts. The patchy drifts are associated with unconfined settings and are interpreted as the outcome of turbidites redistributed by bottom currents. Synchronous interactions between along-slope and across-slope processes appear to have played a crucial role in the formation of large, mounded drifts near submarine canyons.
This study highlights the temporal and spatial complexity of MDSs and provides new insights into their development within submarine canyon systems. Additionally, this work addresses the role that the stratification of deep-water masses could have played in the distribution of sediments along the PCM during the Late Quaternary.
{"title":"Morphology and evolution of a modern mixed (turbidite-contourite) depositional system associated with deeply-incised submarine canyons in the Patagonian Continental Margin","authors":"José I. Isola , Fermín I. Palma , Sebastían Y. Principi , Graziella Bozzano , Ornella Silvestri , Juan P. Ormazabal , Alejandro A. Tassone","doi":"10.1016/j.margeo.2025.107476","DOIUrl":"10.1016/j.margeo.2025.107476","url":null,"abstract":"<div><div>This study integrates a novel multi-beam bathymetry and high-resolution sub-bottom seismic database with previous works, to investigate a Late Quaternary Mixed (turbidite-contourite) Depositional System (MDS) related to a major submarine canyon system located on the Patagonian Continental Margin (PCM) between water depths of 1500 and 4000 m.</div><div>The studied MDS exhibits unique and unusual features, including the along-slope deviation of three submarine canyons, large-mounded drifts (>100 ms TWT) forming downstream of canyons, and small patchy drifts (a few tens ms TWT) accumulating in canyon-free slope areas. The genesis of these features is explained by a temporal substitution from contourite to mixed settings and different styles of interaction between along-slope and across-slope processes.</div><div>The along-slope deviation of the canyons is associated with the temporal substitution of contourite processes dominated period to the establishment of a MDS, marked by increased down-slope activity inferred to have occurred after the Mid-Pleistocene Transition (MPT). The fossil mounded morphologies developed during the dominant contourite period (pre MPT) acted as barriers to the subsequent submarine canyons formed during the increased down-slope activity period (post MPT), causing them to deviate by 90° along the slope.</div><div>After the MPT, spatial intercalation and interactions between along and across slope processes produced patchy and mounded drifts. The patchy drifts are associated with unconfined settings and are interpreted as the outcome of turbidites redistributed by bottom currents. Synchronous interactions between along-slope and across-slope processes appear to have played a crucial role in the formation of large, mounded drifts near submarine canyons.</div><div>This study highlights the temporal and spatial complexity of MDSs and provides new insights into their development within submarine canyon systems. Additionally, this work addresses the role that the stratification of deep-water masses could have played in the distribution of sediments along the PCM during the Late Quaternary.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107476"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107474
Storm Roberts , Alison Raby , Sarah J. Boulton , William Allsop , Alessandro Antonini , Ivo van Balen , David McGovern , Keith Adams , Ian Chandler , Jonas Cels , Irene Manzella
Coastal boulder deposits hold the potential to aid in the reconstruction of past extreme wave events. However, commonly used hydrodynamic equations for calculating wave heights from transported boulders can be inaccurate. New and alternative methods need to be explored in an interdisciplinary way to ensure a more complete picture of the phenomenon of boulder transport is achieved. Through the use of a physical experiment, this study aims to investigate the influence of different tsunami wave types, wave parameters and boulder shapes on boulder transport distance. The experimental results also allow for a novel application of dimensional analysis to enable comparisons with other experiments as well as a field case study. In the experiment an elongate irregularly shaped boulder showed transport distances up to 1 m farther than a cuboid shaped boulder under the influence of the same waves. The irregularly shaped boulder had a predominant transport mode of rolling, whereas the cuboid shaped boulder predominantly underwent sliding transport. Tsunami wave type also influenced boulder transport distances, with N-waves frequently showing greater transport than E-waves of a comparable wave steepness. Key offshore wave and boulder parameters were then compared through dimensional analysis using Buckingham's Pi Theorem, enabling comparisons to other datasets to be made. Data from another published experimental study and a field study in Settai, Japan, showed reasonable agreement, particularly for the shorter period field data. These findings emphasize the importance of incorporating boulder shape, wave type, and dimensional analysis into future studies, providing a foundation for more accurate reconstructions of past tsunami events.
{"title":"Tsunami boulder transport in coastal environments: insights from physical experiments and dimensional analysis","authors":"Storm Roberts , Alison Raby , Sarah J. Boulton , William Allsop , Alessandro Antonini , Ivo van Balen , David McGovern , Keith Adams , Ian Chandler , Jonas Cels , Irene Manzella","doi":"10.1016/j.margeo.2024.107474","DOIUrl":"10.1016/j.margeo.2024.107474","url":null,"abstract":"<div><div>Coastal boulder deposits hold the potential to aid in the reconstruction of past extreme wave events. However, commonly used hydrodynamic equations for calculating wave heights from transported boulders can be inaccurate. New and alternative methods need to be explored in an interdisciplinary way to ensure a more complete picture of the phenomenon of boulder transport is achieved. Through the use of a physical experiment, this study aims to investigate the influence of different tsunami wave types, wave parameters and boulder shapes on boulder transport distance. The experimental results also allow for a novel application of dimensional analysis to enable comparisons with other experiments as well as a field case study. In the experiment an elongate irregularly shaped boulder showed transport distances up to 1 m farther than a cuboid shaped boulder under the influence of the same waves. The irregularly shaped boulder had a predominant transport mode of rolling, whereas the cuboid shaped boulder predominantly underwent sliding transport. Tsunami wave type also influenced boulder transport distances, with N-waves frequently showing greater transport than E-waves of a comparable wave steepness. Key offshore wave and boulder parameters were then compared through dimensional analysis using Buckingham's Pi Theorem, enabling comparisons to other datasets to be made. Data from another published experimental study and a field study in Settai, Japan, showed reasonable agreement, particularly for the shorter period field data. These findings emphasize the importance of incorporating boulder shape, wave type, and dimensional analysis into future studies, providing a foundation for more accurate reconstructions of past tsunami events.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107474"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107439
Chengfeng Xue , Yang Yang , Xibin Han , Ya Ping Wang , Yining Chen , Xiaoming Xia , Jianjun Jia
The sediment source-to-sink process is an important topic in marine sedimentology. However, how sedimentary signals evolve along source-to-sink path remains less clear. This study focuses on the southward shift of the Huanghe River course between AD 1128 and 1855, and the manifestation and variation of sedimentary signals in a natural diffusion system were investigated through sedimentological analysis of three spatially adjacent regions, the abandoned Huanghe Delta, the central coast of Jiangsu, and the Changjiang Delta. Laboratory analyses including Optically Stimulated Luminescence (OSL), geochemical element analysis, and grain size analysis, were conducted. The results show that sedimentary signals manifest in various forms, primarily manifested in two ways: grain size refinement and sedimentation rate acceleration. The fining of grain size is most pronounced in the abandoned Huanghe delta, followed by the central coast of Jiangsu, and is least pronounced in the Changjiang subaqueous delta. The response of the coastal system to the event was delayed by approximately 0–100, 100–300, and 300–500 years for the abandoned Huanghe Delta, the central coast of Jiangsu, and the Changjiang River Delta, respectively. These findings indicate that sediment transport processes exhibit sedimentary signal attenuation and response lag. This study not only highlights the variation along the source-sink path of coastal sedimentary signals but also illuminates the sedimentary record of drastic changes in sediment flux, which will help study the source-to-sink process given the variable changes in sedimentary fluxes.
{"title":"Delayed response of the coastal sedimentary record to the southward shift of the Huanghe (Yellow River) course during AD1128–1855","authors":"Chengfeng Xue , Yang Yang , Xibin Han , Ya Ping Wang , Yining Chen , Xiaoming Xia , Jianjun Jia","doi":"10.1016/j.margeo.2024.107439","DOIUrl":"10.1016/j.margeo.2024.107439","url":null,"abstract":"<div><div>The sediment source-to-sink process is an important topic in marine sedimentology. However, how sedimentary signals evolve along source-to-sink path remains less clear. This study focuses on the southward shift of the Huanghe River course between AD 1128 and 1855, and the manifestation and variation of sedimentary signals in a natural diffusion system were investigated through sedimentological analysis of three spatially adjacent regions, the abandoned Huanghe Delta, the central coast of Jiangsu, and the Changjiang Delta. Laboratory analyses including Optically Stimulated Luminescence (OSL), geochemical element analysis, and grain size analysis, were conducted. The results show that sedimentary signals manifest in various forms, primarily manifested in two ways: grain size refinement and sedimentation rate acceleration. The fining of grain size is most pronounced in the abandoned Huanghe delta, followed by the central coast of Jiangsu, and is least pronounced in the Changjiang subaqueous delta. The response of the coastal system to the event was delayed by approximately 0–100, 100–300, and 300–500 years for the abandoned Huanghe Delta, the central coast of Jiangsu, and the Changjiang River Delta, respectively. These findings indicate that sediment transport processes exhibit sedimentary signal attenuation and response lag. This study not only highlights the variation along the source-sink path of coastal sedimentary signals but also illuminates the sedimentary record of drastic changes in sediment flux, which will help study the source-to-sink process given the variable changes in sedimentary fluxes.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107439"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107469
P.H. Adema , J.T. Eggenhuisen , J. Bleeker , R. Silva Jacinto , E. Miramontes
Turbidity currents are the main agent transferring sediment, carbon, nutrients and pollutants (e.g. micro-plastics) from the continents to the deep sea. They flow through submarine canyons, connecting the continents to the oceans. Along their trajectory, these flows may interact with a suite of oceanographic processes, such as geostrophic contour currents, forming a mixed system, entraining material from the turbidity current into the large-scale ocean system. Turbidity current–contour current interaction is scarcely evaluated and their combined three-dimensional flow structure is poorly constrained. We conducted experiments showing the 3D flow structure of turbidity currents and how this structure is modified by contour currents for different contour current velocities, channel depths, and morphologies. Secondary flow cells are observed in the experimental turbidity currents inside the straight channel. This secondary flow is bi-cellular for the purely gravity-driven experiments. Contour currents collapse this bi-cellular structure into a single cell constrained to the downstream channel margin. Additionally, the contour currents modulate the overspilling behavior of the flow by reducing overspill on the upstream overbank and making overspill thicker and faster on the downstream overbank. Our results illustrate the importance of secondary circulation in turbidity currents and their structural modulation by contour currents.
{"title":"Turbidity current flow structure and its modulation by contour currents: Insights from 3D flume experiments","authors":"P.H. Adema , J.T. Eggenhuisen , J. Bleeker , R. Silva Jacinto , E. Miramontes","doi":"10.1016/j.margeo.2024.107469","DOIUrl":"10.1016/j.margeo.2024.107469","url":null,"abstract":"<div><div>Turbidity currents are the main agent transferring sediment, carbon, nutrients and pollutants (e.g. micro-plastics) from the continents to the deep sea. They flow through submarine canyons, connecting the continents to the oceans. Along their trajectory, these flows may interact with a suite of oceanographic processes, such as geostrophic contour currents, forming a mixed system, entraining material from the turbidity current into the large-scale ocean system<em>.</em> Turbidity current–contour current interaction is scarcely evaluated and their combined three-dimensional flow structure is poorly constrained. We conducted experiments showing the 3D flow structure of turbidity currents and how this structure is modified by contour currents for different contour current velocities, channel depths, and morphologies. Secondary flow cells are observed in the experimental turbidity currents inside the straight channel. This secondary flow is bi-cellular for the purely gravity-driven experiments. Contour currents collapse this bi-cellular structure into a single cell constrained to the downstream channel margin. Additionally, the contour currents modulate the overspilling behavior of the flow by reducing overspill on the upstream overbank and making overspill thicker and faster on the downstream overbank. Our results illustrate the importance of secondary circulation in turbidity currents and their structural modulation by contour currents.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107469"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107449
Mark Lundine , Arthur Trembanis
This study compiles a myriad of previously published and novel results from field-based and remote sensing investigations of Carolina Bays (shallow, circular to elliptic, sandy-rimmed, coastal plain depressions), aiming at identifying possible origin mechanisms as well as future research avenues. These investigations include neural network-based detection and morphometric analysis of over 20,000 Carolina Bays across the Atlantic Coastal Plain from digital elevation models; sedimentological investigations at Bays in Delaware, Virginia, North Carolina, and South Carolina; satellite-based surface water mapping of Bay lakes in North Carolina; a compilation of published geochronological data extracted from Carolina Bay sediments; collection of hydrodynamic data from a Carolina Bay pond; and geologic and geomorphic comparisons between Bays and similar depressions found in North America. This synthesis shows that Carolina Bays and similar depressions are widespread on unglaciated provinces composed of unconsolidated sediments, where wind was likely the main forcing mechanism which initially scoured out the depressions. Wave processes likely produced the Bays' characteristic round to ovate planform shape, with water-level fluctuations leaving behind sand rims as paleoshorelines. Holocene warming, increased humidity, and an increase in vegetation cover has induced more benign geomorphic conditions within Carolina Bays, during which finer sediment and organic matter has filled in these depressions. Modern observations of Carolina Bays and related features show little modern geomorphic activity. Geochronological data shows that Bays originated and underwent geomorphic modification from Marine Isotope Stage 5 to Marine Isotope Stage 1, coeval with the growth and decay of the Laurentide Ice Sheet, as well as with the development of nearby sand dunes. The available geochronological evidence is not compatible with an impact origin for the Bays, particularly one related to the Younger Dryas impact hypothesis or one related to Australasian tektites dating to 788 ka. The results of this synthesis should encourage future research into field-based, modeling, and synthetic investigations of Bays and similar depressions.
{"title":"Investigating the origin and dynamics of Carolina Bays","authors":"Mark Lundine , Arthur Trembanis","doi":"10.1016/j.margeo.2024.107449","DOIUrl":"10.1016/j.margeo.2024.107449","url":null,"abstract":"<div><div>This study compiles a myriad of previously published and novel results from field-based and remote sensing investigations of Carolina Bays (shallow, circular to elliptic, sandy-rimmed, coastal plain depressions), aiming at identifying possible origin mechanisms as well as future research avenues. These investigations include neural network-based detection and morphometric analysis of over 20,000 Carolina Bays across the Atlantic Coastal Plain from digital elevation models; sedimentological investigations at Bays in Delaware, Virginia, North Carolina, and South Carolina; satellite-based surface water mapping of Bay lakes in North Carolina; a compilation of published geochronological data extracted from Carolina Bay sediments; collection of hydrodynamic data from a Carolina Bay pond; and geologic and geomorphic comparisons between Bays and similar depressions found in North America. This synthesis shows that Carolina Bays and similar depressions are widespread on unglaciated provinces composed of unconsolidated sediments, where wind was likely the main forcing mechanism which initially scoured out the depressions. Wave processes likely produced the Bays' characteristic round to ovate planform shape, with water-level fluctuations leaving behind sand rims as paleoshorelines. Holocene warming, increased humidity, and an increase in vegetation cover has induced more benign geomorphic conditions within Carolina Bays, during which finer sediment and organic matter has filled in these depressions. Modern observations of Carolina Bays and related features show little modern geomorphic activity. Geochronological data shows that Bays originated and underwent geomorphic modification from Marine Isotope Stage 5 to Marine Isotope Stage 1, coeval with the growth and decay of the Laurentide Ice Sheet, as well as with the development of nearby sand dunes. The available geochronological evidence is not compatible with an impact origin for the Bays, particularly one related to the Younger Dryas impact hypothesis or one related to Australasian tektites dating to 788 ka. The results of this synthesis should encourage future research into field-based, modeling, and synthetic investigations of Bays and similar depressions.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107449"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107467
Gemma Ercilla , Jesús Galindo-Zaldívar , Carmen Juan , Ferran Estrada , Jorge Iglesias , Javier Valencia , Víctor Tendero-Salmerón , Elia d'Acremont , María del Carmen Fernández-Puga , Lourdes González-Castillo , Asier Madarieta-Txurruka , Desiree Palomino , Manuel Teixeira , Juan Tomás Vázquez
Through a comparison of the physiography and Quaternary deposits and features of three tectonically deformed Iberian continental margins by the NW–SE convergent Eurasia-Iberian-Africa plates, we attempt to address the influence of the interplay of tectonics and sedimentation on their geomorphology. The areas include the currently active southern Iberian Alboran and Gulf of Vera margins in the SW Mediterranean and the inactive northern Iberian Cantabrian margin in the Atlantic. The margin study comprises two major physiographic compartments, the continental shelf and the distal margin, where the latter also includes the adjacent bathyal water depths. Similarities and differences are highlighted in the tectonic influences and their signatures in the sedimentary geomorphology during the Quaternary. On the continental shelf, the active or inactive onshore uplift appears to have conditioned the seafloor gradients and the preservation of the Quaternary deposits, which subsequently influenced their width. In the distal continental margin, offshore regional structural features (whether active or inactive) govern the complex and oversteepened topography, overall geometry of the sea basin, along-margin intraslope basins and regional tectonic tilting, influencing all the downslope and alongslope sedimentary processes. Thus, Quaternary tectonic processes and/or inherited morphotectonic parameters have influenced the geomorphology of shelf regressive deposits, canyons, gullies, fans, mass movement deposits, and contourites. Two types of tectonic margins based on sedimentary geomorphology are characterised: dismantled (Gulf of Vera and Cantabrian margins) and constructional (Iberian Alboran margin). This study has relevance far beyond the Iberian regional scale because it provides insights into the tectonic signatures of sedimentary geomorphology. The categorised margin types may serve as analogues for contemporary marine sedimentary basins where tectonics plays a prominent role in sediment transport, deposition, erosion, and remobilisation via their influence on both active and inactive topography.
{"title":"Geomorphology of the northern and southern continental margins of the Iberian Peninsula: Quaternary interplay of tectonics and sedimentation","authors":"Gemma Ercilla , Jesús Galindo-Zaldívar , Carmen Juan , Ferran Estrada , Jorge Iglesias , Javier Valencia , Víctor Tendero-Salmerón , Elia d'Acremont , María del Carmen Fernández-Puga , Lourdes González-Castillo , Asier Madarieta-Txurruka , Desiree Palomino , Manuel Teixeira , Juan Tomás Vázquez","doi":"10.1016/j.margeo.2024.107467","DOIUrl":"10.1016/j.margeo.2024.107467","url":null,"abstract":"<div><div>Through a comparison of the physiography and Quaternary deposits and features of three tectonically deformed Iberian continental margins by the NW–SE convergent Eurasia-Iberian-Africa plates, we attempt to address the influence of the interplay of tectonics and sedimentation on their geomorphology. The areas include the currently active southern Iberian Alboran and Gulf of Vera margins in the SW Mediterranean and the inactive northern Iberian Cantabrian margin in the Atlantic. The margin study comprises two major physiographic compartments, the continental shelf and the distal margin, where the latter also includes the adjacent bathyal water depths. Similarities and differences are highlighted in the tectonic influences and their signatures in the sedimentary geomorphology during the Quaternary. On the continental shelf, the active or inactive onshore uplift appears to have conditioned the seafloor gradients and the preservation of the Quaternary deposits, which subsequently influenced their width. In the distal continental margin, offshore regional structural features (whether active or inactive) govern the complex and oversteepened topography, overall geometry of the sea basin, along-margin intraslope basins and regional tectonic tilting, influencing all the downslope and alongslope sedimentary processes. Thus, Quaternary tectonic processes and/or inherited morphotectonic parameters have influenced the geomorphology of shelf regressive deposits, canyons, gullies, fans, mass movement deposits, and contourites. Two types of tectonic margins based on sedimentary geomorphology are characterised: dismantled (Gulf of Vera and Cantabrian margins) and constructional (Iberian Alboran margin). This study has relevance far beyond the Iberian regional scale because it provides insights into the tectonic signatures of sedimentary geomorphology. The categorised margin types may serve as analogues for contemporary marine sedimentary basins where tectonics plays a prominent role in sediment transport, deposition, erosion, and remobilisation via their influence on both active and inactive topography.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107467"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107447
Amando P.E. Lasabuda , Domenico Chiarella , Tor Oftedal Sømme , Sten-Andreas Grundvåg , Isak Eikelmann , Stig-Morten Knutsen , Anthony George Doré , Jan Sverre Laberg , Tom Arne Rydningen , Alfred Hanssen , Bent Kjølhamar
During the Paleocene and Eocene, many Arctic basins experienced multiple, yet synchronous periods of increased sedimentation rates. Several causal factors have been suggested including major volcanic events, tectonic plate reorganization and plate break-up, as well as widespread uplift along with contemporaneous and short-lived hyperthermal events. However, the significance of and relation between tectonic and climatic forcing on Arctic sediment transfer during the early Paleogene are poorly understood. In this case study from the Barents Shelf margin in the Norwegian Arctic, we present previously unpublished cores combined with exploration wells, and new high-resolution 3D seismic data to investigate sedimentary stacking patterns and geomorphological features in the Sørvestsnaget Basin. Our integrated investigations reveal the development of climate-controlled and tectonically-driven submarine fans. The PETM fans display an individual fan as a result of single depositional event compared to the middle Eocene fans that show stacked submarine fans probably deposited during multi-phase events. Our stratigraphic forward modelling analysis indicates that regional-scale tectonically induced uplift significantly increased the amount of sand delivered to the basin as documented by a thickening of the basin fill succession. The climatic component contributes to sand transport variability to the basin, and thus the temporal evolution pattern of sand is much varied. Finally, we discuss our findings with the tectonic and climatic forcing factors in a circum-Arctic perspective.
{"title":"Impact of Paleocene–Eocene tectonic and climatic forcing on Arctic sediment transfer variability: SW Barents Sea, Norway","authors":"Amando P.E. Lasabuda , Domenico Chiarella , Tor Oftedal Sømme , Sten-Andreas Grundvåg , Isak Eikelmann , Stig-Morten Knutsen , Anthony George Doré , Jan Sverre Laberg , Tom Arne Rydningen , Alfred Hanssen , Bent Kjølhamar","doi":"10.1016/j.margeo.2024.107447","DOIUrl":"10.1016/j.margeo.2024.107447","url":null,"abstract":"<div><div>During the Paleocene and Eocene, many Arctic basins experienced multiple, yet synchronous periods of increased sedimentation rates. Several causal factors have been suggested including major volcanic events, tectonic plate reorganization and plate break-up, as well as widespread uplift along with contemporaneous and short-lived hyperthermal events. However, the significance of and relation between tectonic and climatic forcing on Arctic sediment transfer during the early Paleogene are poorly understood. In this case study from the Barents Shelf margin in the Norwegian Arctic, we present previously unpublished cores combined with exploration wells, and new high-resolution 3D seismic data to investigate sedimentary stacking patterns and geomorphological features in the Sørvestsnaget Basin. Our integrated investigations reveal the development of climate-controlled and tectonically-driven submarine fans. The PETM fans display an individual fan as a result of single depositional event compared to the middle Eocene fans that show stacked submarine fans probably deposited during multi-phase events. Our stratigraphic forward modelling analysis indicates that regional-scale tectonically induced uplift significantly increased the amount of sand delivered to the basin as documented by a thickening of the basin fill succession. The climatic component contributes to sand transport variability to the basin, and thus the temporal evolution pattern of sand is much varied. Finally, we discuss our findings with the tectonic and climatic forcing factors in a circum-Arctic perspective.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107447"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.margeo.2024.107438
Pedro Dunán-Avila , Christine Authemayou , Marion Jaud , Kevin Pedoja , Julius Jara-Muñoz , Stephane Bertin , Leandro Peñalver-Hernández , France Floc'h , Arelis Nuñez-Labañino , Patricio Winckler , Jean Pierre-Toledo , Pedro Benítez-Frometa , Hassan Ross-Cabrera , Pauline Letortu , Angel Raúl Rodríguez-Valdés , Noel Coutín-Lobaina , Denovan Chauveau
Coastal boulder deposits, observed worldwide, provide geomorphological evidence of extreme wave events such as storms, hurricanes and tsunamis. Theoretical formulations have been developed for determining hydrodynamic conditions responsible for boulder emplacement on the shore, which increasingly make use of boulder geometry and associated site geomorphology. Nevertheless, information on extreme events responsible for the emplacement of coastal boulders is rarely available, meaning there has been limited opportunity to test existing formulations in the light of real hydrodynamic and geomorphic data. In this study, we take advantage of the important record of coastal boulder deposits on Cuba Island to compare the hydrodynamic parameters (minimum flow velocity) deduced from the boulders' morphology and emplacement characteristics, with hydrodynamic conditions (maximum wave height and orbital velocity) that occurred during the tropical cyclones responsible for the boulders' actual emplacement. We selected four sites where three hurricanes have emplaced five boulders on low-lying coral reef terraces over the last 50 years. Using terrestrial Structure-from-Motion photogrammetry, we determined with precision the boulders' shape and volume, which in combination with density, mode of emplacement and distance from the shore, were used to calculate the minimum flow velocity responsible for dislocation of the coral reef terrace and inland transport. To serve as comparisons, available modelled data of wave height and period were used to estimate the maximum orbital velocity that possibly occurred during the weather event using linear wave theory. Our results show that for all boulders studied except one, there is a good agreement between the values of minimum flow and maximal orbital velocities, with minimum flow velocities for boulder emplacement consistently smaller than the maximum wave orbital velocity during the weather event. The difference observed for one boulder is attributed to specific site effects, highlighting in this case the limitation of using distant hydrometeorological data for characterizing wave processes responsible for coastal boulder deposits. Helped by detailed data collected on boulders with large differences in morphology including size, and mode of emplacement, this study confirms the pertinence of using formulations relating boulder morphology and site characteristics to the minimum flow velocity that detached and transported the boulder. It further emphasizes the importance of obtaining adequate boulder and geomorphic setting characterizations to link geomorphological proxies and extreme wave events.
{"title":"Geomorphological signatures of known hurricanes and validation of theoretical emplacement formulations: Coastal boulder deposits on Cuban low-lying marine terraces","authors":"Pedro Dunán-Avila , Christine Authemayou , Marion Jaud , Kevin Pedoja , Julius Jara-Muñoz , Stephane Bertin , Leandro Peñalver-Hernández , France Floc'h , Arelis Nuñez-Labañino , Patricio Winckler , Jean Pierre-Toledo , Pedro Benítez-Frometa , Hassan Ross-Cabrera , Pauline Letortu , Angel Raúl Rodríguez-Valdés , Noel Coutín-Lobaina , Denovan Chauveau","doi":"10.1016/j.margeo.2024.107438","DOIUrl":"10.1016/j.margeo.2024.107438","url":null,"abstract":"<div><div>Coastal boulder deposits, observed worldwide, provide geomorphological evidence of extreme wave events such as storms, hurricanes and tsunamis. Theoretical formulations have been developed for determining hydrodynamic conditions responsible for boulder emplacement on the shore, which increasingly make use of boulder geometry and associated site geomorphology. Nevertheless, information on extreme events responsible for the emplacement of coastal boulders is rarely available, meaning there has been limited opportunity to test existing formulations in the light of real hydrodynamic and geomorphic data. In this study, we take advantage of the important record of coastal boulder deposits on Cuba Island to compare the hydrodynamic parameters (minimum flow velocity) deduced from the boulders' morphology and emplacement characteristics, with hydrodynamic conditions (maximum wave height and orbital velocity) that occurred during the tropical cyclones responsible for the boulders' actual emplacement. We selected four sites where three hurricanes have emplaced five boulders on low-lying coral reef terraces over the last 50 years. Using terrestrial Structure-from-Motion photogrammetry, we determined with precision the boulders' shape and volume, which in combination with density, mode of emplacement and distance from the shore, were used to calculate the minimum flow velocity responsible for dislocation of the coral reef terrace and inland transport. To serve as comparisons, available modelled data of wave height and period were used to estimate the maximum orbital velocity that possibly occurred during the weather event using linear wave theory. Our results show that for all boulders studied except one, there is a good agreement between the values of minimum flow and maximal orbital velocities, with minimum flow velocities for boulder emplacement consistently smaller than the maximum wave orbital velocity during the weather event. The difference observed for one boulder is attributed to specific site effects, highlighting in this case the limitation of using distant hydrometeorological data for characterizing wave processes responsible for coastal boulder deposits. Helped by detailed data collected on boulders with large differences in morphology including size, and mode of emplacement, this study confirms the pertinence of using formulations relating boulder morphology and site characteristics to the minimum flow velocity that detached and transported the boulder. It further emphasizes the importance of obtaining adequate boulder and geomorphic setting characterizations to link geomorphological proxies and extreme wave events.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"480 ","pages":"Article 107438"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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