Marine Geology最新文献

{"title":"A landslide tsunami hazard assessment in the Makran Subduction Zone","authors":"Amin Rashidi ,&nbsp;Mohammad Mokhtari ,&nbsp;Katsuichiro Goda ,&nbsp;Mehdi Masoodi ,&nbsp;Parvaneh Faridi","doi":"10.1016/j.margeo.2025.107580","DOIUrl":"10.1016/j.margeo.2025.107580","url":null,"abstract":"<div><div>Seismic profiles have revealed historical submarine landslides within the western part of the Makran Subduction Zone (MSZ). A specific underwater landslide, identified off the coast of Chabahar, Iran, has been modeled to assess the potential hazard of the resultant tsunami waves in the MSZ. This submerged landslide near Chabahar has a volume of 7 km³. To evaluate the tsunami hazard, three scenarios have been developed: one static and two dynamic. According to the simulations<strong>,</strong> Chabahar experiences high waves, reaching heights of 5 m around its coast, with corresponding runup amplitudes of up to 10 m. Emphasizing the significance of dynamic considerations in understanding the tsunamigenesis of submarine landslides, the two dynamic scenarios differ primarily in landslide travel distance and, consequently, duration. The numerical modeling outcomes indicate that the dynamic scenario with the longer travel distance yields higher tsunami waves, reaching a maximum height of 15 m in the Oman Sea. Conversely, the other dynamic scenario generates waves with amplitudes similar to those produced in the static scenario. It takes about 15 min for the tsunami to reach Chabahar Station. Major ports in the region, including Chabahar, Jask, Muscat, and Sur, face elevated threats from the potential impact of this landslide-triggered tsunami. Notably, the shoreline of Pakistan exhibits a comparatively lower threat level in contrast to Iran and Oman. Looking ahead, future studies aim to compile a comprehensive database of tsunamigenic scenarios based on all potential landslides identified through seismic sections and bathymetry topology. This will enhance our understanding of the region's tsunami hazard from landslide-tsunamis.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107580"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of exposure on the vertical variation of mudflat sediment erodibility","authors":"Chuning Dong ,&nbsp;Yongping Chen ,&nbsp;Ian Townend ,&nbsp;Yiming Wu ,&nbsp;Zichao Guo ,&nbsp;Qin Jiang ,&nbsp;Giovanni Coco ,&nbsp;Karin R. Bryan ,&nbsp;Zeng Zhou","doi":"10.1016/j.margeo.2025.107579","DOIUrl":"10.1016/j.margeo.2025.107579","url":null,"abstract":"<div><div>Variations in meteorological conditions are known to influence the erodibility of sediments on tidal flats. However, there is limited understanding of how evaporation during exposure affects the stability of mudflats. In this study, we conducted field tests spanning 5 days in January 2021 and 14 days in August 2022 in the intertidal zone along the Yancheng coast in Jiangsu Province, China. We selected critical shear stress for erosion (τ_cr) and shear strength (SS) as erosion parameters, and analyzed the variations in hydrodynamic and meteorological parameters, and vertical sediment properties. Our results indicate that bed exposure in summer significantly enhances sediment stability, an effect that extends below the surface layer and even to deeper layers. As exposure duration increases, the differences with depth become more pronounced, leading to increased variability in τ_cr. This vertical gradient increases with exposure duration and atmospheric evaporation intensity, with both the values of vertical τ_cr and SS in summer showing a nearly 2 times increase compared to that in winter. The primary controlling parameter for changes in sediment erodibility during summer exposure is water content, while in winter, the mean grain size (D50) and salinity are more significant. The causal relationship between summer and winter exposure and resistance to vertical erosion of mudflats, shown in this study, underscores the need to pay greater attention to the seasonal influence of atmospheric processes on the spatial heterogeneity of sediments that arises from tidal exposure.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107579"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovery of the world's largest cliff-top boulder: Initial insights and numerical simulation of its transport on a 30–40 m high cliff on Tongatapu (Tonga)","authors":"Martin Köhler ,&nbsp;Annie Lau ,&nbsp;Koki Nakata ,&nbsp;Kazuhisa Goto ,&nbsp;James Goff ,&nbsp;Daniel Köhler ,&nbsp;Mafoa Penisoni","doi":"10.1016/j.margeo.2025.107567","DOIUrl":"10.1016/j.margeo.2025.107567","url":null,"abstract":"<div><div>This study provides the first scientific investigation of the <em>Maka Lahi</em> boulder, a large limestone cliff-top boulder, measuring 14 × 12 × 6.7 m and weighing approximately 1180 t, located 200 m inland at 39 m elevation on the southern coast of Tongatapu, Tonga. The boulder is one of the largest known wave-transported boulders worldwide. Fieldwork conducted in 2024 revealed its presence, geomorphic setting, and karstification features. Utilizing numerical modelling, we established that wave heights of approximately 50 m and periods of 90 s were required to transport the boulder from its cliff-edge origin, suggesting that its emplacement likely resulted from a landslide-triggered tsunami event. U/Th dating of flowstone on the surface is indicative of a minimum age of 6891 cal yr BP and contributes critical evidence of a significant early Holocene tsunami event in Tonga. Notably, this represents the earliest known Holocene tsunami in the Pacific, offering new insights into the long-term history of extreme wave events in the region. This research strengthens the understanding of megaclast transport mechanisms and their implications for coastal hazard assessments in tsunami-prone regions.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107567"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sources and transport-sedimentation processes of surficial detrital sediments in the southwest Arabian Sea: Insights from grain-size end-member component analysis","authors":"Dongyi Li,&nbsp;Yonghang Xu,&nbsp;Jian Chen,&nbsp;Yunhai Li,&nbsp;Liang Wang","doi":"10.1016/j.margeo.2025.107578","DOIUrl":"10.1016/j.margeo.2025.107578","url":null,"abstract":"<div><div>The Arabian Sea is an ideal region for exploring the sources and transport-sedimentation processes of surficial detrital sediments. Notably, grain-size end-member component (EMC) separation methods are powerful tools for this exploration. Through integration of this method with mineralogical and morphological characterization analyses, we identified four EMCs (EMC1-EMC4) suitable for the study area and elucidated the role of multiple forcings in controlling sources and transport-sedimentation processes. The findings revealed that variations in sources and diverse transport mechanisms govern the grain-size distribution patterns of surficial detrital sediments in the study area. The EMC1 ultrafine end-member is dominated by basalt weathering products from the Deccan Plateau and the west Indian Ocean, and is slightly influenced by aeolian dust from the interior of the Arabian Peninsula and northeast Africa. EMC2, EMC3, and EMC4 represent fine, coarse, and ultra-coarse fractions of aeolian dust primarily from different regions of the Arabian Peninsula, respectively. Monsoon circulation transports smectite-rich ultrafine sediments eastward across the Indian shelf, while Lower Circumpolar Deep Water (LCDW) carries them northward over long distances. Furthermore, the LCDW flows anticlockwise in the north Somali Basin, hindered by the Carlsberg Ridge, leading to the deposition of the ultrafine sediments it carries. Various wind systems interactions enable size-selective transport: fine EMCs traverse via mid-tropospheric pathways, whereas coarse EMCs are confined to the lower troposphere. The southwest monsoon facilitating the transport of fine EMC southward while impeding the transport-sedimentation of coarse EMCs.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107578"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controls of paleosedimentary environments and anthropogenic activities on coastal groundwater salinization: A case study of Laizhou Bay, China","authors":"Zhen Cui ,&nbsp;Guangquan Chen ,&nbsp;Xin Shan ,&nbsp;Haitao Zhang ,&nbsp;Qingjie Zhou ,&nbsp;Tengfei Fu ,&nbsp;Hongjun Yu ,&nbsp;Xingyong Xu ,&nbsp;Shenliang Chen","doi":"10.1016/j.margeo.2025.107594","DOIUrl":"10.1016/j.margeo.2025.107594","url":null,"abstract":"<div><div>Groundwater salinization presents a substantial environmental challenge for coastal regions globally, particularly along the southern shore of Laizhou Bay. The processes contributing to groundwater salinization are intricate and involve interactions between natural factors and human activities. This study examines the mechanisms underlying groundwater salinization at varying depths in the southern Laizhou Bay area, with a particular emphasis on the effects of extensive groundwater extraction. Excessive groundwater extraction has intensified salinization by altering hydraulic gradients and promoting seawater intrusion. Utilizing sediment and pore water samples from two boreholes (SG100 and WF80) alongside shallow seismic data, we identified that sedimentary strata consisting of alternating marine and terrestrial deposits, formed during multiple transgressive events since the Late Pleistocene, are a significant source of salinity. Paleoenvironmental reconstructions based on grain size analysis, combined with Cl/Br ratios and stable isotope analysis, indicated that modern seawater intrusion is a primary driver of shallow groundwater salinization. In contrast, variations in deep groundwater salinity reflect differing paleoenvironmental recharge conditions. Ancient riverbed sediments exhibit high permeability, providing an efficient pathway for the transport of water and salts from upstream freshwater bodies. This process facilitates the dilution within the aquifer, leading to the formation of low-salinity groundwater. In contrast, the low permeability of floodplain sediments significantly restricts the renewal capacity of water bodies. As a result, the saline water layer maintains a high salinity state over extended periods due to the combined effects of evaporation and limited recharge. Notably, offshore freshwater was detected within ancient river channel deposits. These findings underscore the intricate interplay between sedimentary evolution and anthropogenic activities in influencing groundwater salinization, highlighting the necessity for scientifically informed, water-type-specific management strategies.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"487 ","pages":"Article 107594"},"PeriodicalIF":2.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The geomorphic evolution of the Tasmantid Seamount Chain","authors":"Alysha M. Johnson ,&nbsp;Mark E. Dickson ,&nbsp;Sarah Hamylton ,&nbsp;Colin D. Woodroffe","doi":"10.1016/j.margeo.2025.107560","DOIUrl":"10.1016/j.margeo.2025.107560","url":null,"abstract":"<div><div>Oceanic volcanoes develop distinct post-eruptive morphologies depending on the geomorphic conditions they experience. Submerged, truncated, flat-topped volcanoes, known as guyots, result from marine erosion and subsidence, whereas on reefs or carbonate-capped volcanoes, carbonate accretion veneers the summit. New and existing bathymetric data are utilised to identify different geomorphic forms of oceanic volcanoes in the Tasmantid Seamount Chain, a hotspot chain off the east coast of Australia, dated from ∼6 Ma in the south to &gt;50 Ma in the north. Profiles and slope calculations across long and short axes provide morphometric values on the basis of which four morphologic forms are identified: seamount, guyot, modern reef, and carbonate-capped guyot. Volcanoes which erupted on oceanic lithosphere are estimated to have subsided at an average rate of 46.5 mMyr⁻¹, faster than the subsidence rate of volcanoes that erupted on continental lithosphere (33.0 mMyr⁻¹). The guyots are estimated to have eroded at an average rate of 1.9 ± 0.5 kmMyr⁻¹. Substantial carbonate accretion has formed on the summits of eleven volcanoes, ranging in thickness from 1146 m in the north to 93 m in the south. The geomorphic evolution of the Tasmantid Seamount Chain, since the Oligocene, is synthesised into a conceptual model. This study finds that the post-eruptive morphology of each volcano in the chain is a product of the combined influence of the northward movement of the Australian Plate, erosion, subsidence, and carbonate accretion.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"486 ","pages":"Article 107560"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing spatial interpolation methods for deep-time organic carbon burial in epicontinental seas by taking Sunda Shelf as an example","authors":"Yida Yang ,&nbsp;Pengfei Ma ,&nbsp;Xiumian Hu ,&nbsp;Yuan Gao ,&nbsp;Chengshan Wang","doi":"10.1016/j.margeo.2025.107566","DOIUrl":"10.1016/j.margeo.2025.107566","url":null,"abstract":"<div><div>Quantifying the burial of organic carbon (OC) in epicontinental seas is crucial for understanding its role in regulating global long-term carbon cycle and climate. Utilizing spatial interpolation methods, prior works have quantified OC burial globally or regionally based on limited, unevenly distributed measurements. However, there remains a notable lack of comparative studies and assessments regarding their applicability and uncertainty in deep-time research. Taking the middle Miocene Sunda Shelf OC burial estimation as an example, four popular spatial interpolation methods are assessed quantitatively and qualitatively, including Thiessen polygons, Inverse Distance Weighting (IDW), Ordinary Kriging (OK) and Random Forests (RF). Based on quantitative and qualitative evaluation, the data-driven RF method demonstrates superior performance due to fewer assumptions, effectively capturing nonlinear relationships and complex spatial patterns in heterogeneous, non-Gaussian deep-time data, and demonstrating strong generalizability and robustness. High-resolution RF-based reassessment reveals significant spatial-temporal heterogeneity of OC burial on the Sunda Shelf between the Miocene Climatic Optimum (MCO) and Middle Miocene Climate Transition (MMCT). Although the overall OC burial and sediment accumulation rates (SAR) increase during the MMCT, notable spatial discrepancies emerge, with OC burial rates elevated near basin margins but decreased in distal regions. These variations primarily reflect the combined influences of eustatic sea-level fall and enhanced terrigenous input, highlighting the complex interplay of factors modulating OC burial efficiency. Machine learning methods such as RF prove highly effective in handling deep-time spatial data, but their application should be adapted to specific objectives, geological conditions, and data characteristics.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"486 ","pages":"Article 107566"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology and Holocene activity of a high-latitude Canyon – Channel system: The proximal Lofoten Basin channel system (Norwegian Sea)","authors":"Hilde B. Amundsen ,&nbsp;Jan Sverre Laberg,&nbsp;Daniel H. Wiberg ,&nbsp;Tom Arne Rydningen,&nbsp;Amando P.E. Lasabuda ,&nbsp;Stine Bjordal-Olsen,&nbsp;Matthias Forwick","doi":"10.1016/j.margeo.2025.107574","DOIUrl":"10.1016/j.margeo.2025.107574","url":null,"abstract":"<div><div>Canyon – channel systems have the potential to be biological and marine litter “hotspots”, and they can act as important carbon sinks. However, knowledge about the modern (Holocene) activity of many of these systems remains poor. This includes the high-latitude Andøya Canyon - Lofoten Basin Channel located in the Norwegian Sea (∼69^oN). This study focuses on the proximal Lofoten Basin Channel and associated deposits (the Andøya Canyon is previously reported). The Lofoten Basin Channel includes two channel branches representing the canyon continuation beyond the foot of the continental slope, terminating in an area resembling a braidplain including braided channels, bars, as well as MTDs. Sediment cores included sandy turbidites. Based on their age and Ca/Fe ratios, we infer that the youngest sandy turbidites were deposited during the same event, suggesting that the event covered an area of c. 120 km × 20 km. Assuming an average thickness of ∼10 cm, this result in a volume of ∼0,24 km³ of terrigenous sand deposited in the basin over an area of ∼2400 km² sometime during the period from 3.7 to 2.4 kyrs BP. This equals a sand thickness of 4.8 m in the c. 50 km long and 1 km wide thalweg part of the Andøya Canyon, here considered to be the source area. The sand could derive from failure of sandy accumulations within the canyon and/or from sand piracy. Another aspect of this Holocene turbidite event is that it represented a substantial export of inorganic carbon into the deep sea which in this way got buried, representing a carbon sink removing carbon from the carbon cycle (a carbon draw-down effect). These results shows that the canyon is a potential source and route for sediments that may cover ∼2400 km² of the sea floor, large deep-sea areas that also represent carbon sinks so far not well accounted for.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"486 ","pages":"Article 107574"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A coral microatoll record of sea-level rise, interseismic deformation, and El Niño in La Union, Philippines since 1906 CE","authors":"Gina M. Sarkawi ,&nbsp;Aron J. Meltzner ,&nbsp;Dongju Peng ,&nbsp;Joanne T.Y. Lim ,&nbsp;Xinnan Li ,&nbsp;Rohan Gautam ,&nbsp;Anandh Gopal ,&nbsp;Andrew Mitchell ,&nbsp;Loraine Faye Sarmiento ,&nbsp;Jennifer Weil-Accardo ,&nbsp;Kathrine V. Maxwell ,&nbsp;Junki Komori ,&nbsp;Noelynna T. Ramos","doi":"10.1016/j.margeo.2025.107565","DOIUrl":"10.1016/j.margeo.2025.107565","url":null,"abstract":"<div><div>Relative sea level (RSL) along western Luzon is influenced by climate change, tectonic deformation, and the El Niño–Southern Oscillation. Long, high-resolution records of past changes in sea level and land level are crucial to distinguish these contributions for forecasting future RSL or identifying tectonic hazards. Coral microatolls are invaluable proxies for reconstructing RSL, but their interpretation relies on understanding how short- and long-term changes are recorded in the coral skeleton. We analyzed growth bands from 1906 to 2018 CE of a <em>Porites</em> microatoll from Balaoan, La Union, Philippines, using X-rays of vertical cross sections. The microatoll's surface morphology, annual banding, and growth history reveal RSL rise during its lifetime punctuated by 17 diedowns. Coral diedowns generally coincide with low water near the site, often resulting from El Niño events. Excluding eroded sections, 10 of the 11 strongest El Niños since 1918 produced a diedown. Similarly, excluding a diedown caused by the coral tilting, 10 of the 12 preserved diedowns exceeding 3 mm in amplitude occurred during strong El Niños. Between 1948 and 2018 CE, RSL rose at 1.3 ± 1.8 mm/yr (2σ). Comparing sea-level rates from satellite altimetry and RSL from the coral, we estimate vertical land motion at −0.1 ± 12.1 mm/yr between 1995 and 2018 CE. The indicative meaning at Balaoan, defined as the relationship between local water levels and the highest level of growth of a coral microatoll before its most recent diedown, is estimated at 31.5 ± 10.0 cm (2σ) above lowest astronomical tide.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"486 ","pages":"Article 107565"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrodynamic processes and extreme events recognized from the sedimentary records at ancient Port Shuomen in the Oujiang River mouth, Southeast China","authors":"Xin Wei ,&nbsp;Yanhua Liang ,&nbsp;Tuanhui Liu ,&nbsp;Zhihang Ma ,&nbsp;Xiaolin Ma ,&nbsp;Shiyu Ji ,&nbsp;Fangyou Lin ,&nbsp;Hao Xu ,&nbsp;Zhanghua Wang (王张华)","doi":"10.1016/j.margeo.2025.107562","DOIUrl":"10.1016/j.margeo.2025.107562","url":null,"abstract":"<div><div>Identifying extreme events from geological records is fundamental to Paleotempestology. Archaeological excavations at the ancient Port Shuomen on the Southeast Chinese coast have provided high-resolution stratigraphic data for recognizing deposits associated with extreme events. This study examined three profiles from the Port and surficial sediments from modern colluvial and estuarine environments in the lower Oujiang River basin. Analyses including chronology, sedimentology, alkaline earth metal geochemistry, and ancient environmental DNA (eDNA) were performed on the sedimentary records to identify hydrodynamic processes and extreme events during the Song Dynasty (960–1279 CE). Comparisons of alkaline earth metal compositions between the profiles and surficial sediments suggest a reduction in salinity at the Port Shuomen, driven by increased freshwater discharge during the mid- to late-Northern Song Dynasty. High eDNA concentrations and consistent frequency distributions of fragment lengths further suggest rapid channel siltation during a single typhoon season. Following this typhoon season, the Port evolved into tide-dominated regime and experienced five periods of flooding, three of which were characterized by intensified salinity intrusion as evidenced by elevated Sr content. In particular, a mud unit (U10) exhibits the highest Sr content and is interpreted as a depositional record of extreme typhoon events that occurred in the 1160s CE. Furthermore, this study demonstrates that in estuarine environments, the preservation of eDNA is more impacted by sedimentary processes than grain size.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"486 ","pages":"Article 107562"},"PeriodicalIF":2.6,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851841","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}