Sedimentary Geology最新文献

{"title":"Residual beachrock and coastal eolianite patches without anthropogenic components on the eastern coast of Cantabria (Spain)","authors":"Javier Elorza ,&nbsp;Clemente Recio","doi":"10.1016/j.sedgeo.2025.106925","DOIUrl":"10.1016/j.sedgeo.2025.106925","url":null,"abstract":"<div><div>Isolated beachrocks appear as relict patches normally attached to protrusions of lower-upper Cretaceous limestones outcropping at Noja, Somo and Sonabia zones in the eastern coast of Cantabria (northern Spain). Additionally, remnant cemented dunes (eolianites) are present at different heights above present sea level. We concentrate on the petrographic features of first-generation cements, that are different in the lower foreshore and upper foreshore-backshore. δ¹³C and δ¹⁸O values measured in the cements of both beachrock and eolianite suggest mixing between marine and meteoric waters, generally with preponderance of the continental contribution. In all the studied examples, <em>Coccus</em>-type bacterial activity has been recognized, suggesting that it is the main trigger for the initiation of cementation. ¹⁴C dating shows that the different cementations studied did not occur in a single event at a specific age, since there is a notable variation, from the highest values of 8760 years BP to 2740 years BP, despite the beachrock patches being at the height of the current intertidal zone. In the non-cemented intertidal sands that form the current beaches there are also important variations, difficult to justify, from similar ages of 3050 years BP (Noja) and 3010 years BP (Somo) to a mere 390 years BP (Sonabia).</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"486 ","pages":"Article 106925"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580846","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}

{"title":"Constructive and destructive processes affecting a tufa system in semi-arid Sierras Pampeanas, Argentina","authors":"Santiago Centorbi ,&nbsp;R. Agustin Mors ,&nbsp;Ricardo A. Astini ,&nbsp;Fernando J. Gomez ,&nbsp;Brenda Y. Alvarez","doi":"10.1016/j.sedgeo.2025.106931","DOIUrl":"10.1016/j.sedgeo.2025.106931","url":null,"abstract":"<div><div>This study focuses on a modern tufa system developing under a semi-arid climate at mid-latitude in the Sierras Pampeanas of central Argentina, currently undergoing degradation. The research integrates a geomorphological, sedimentological, mineralogical, and hydrochemical approach to analyze constructive and destructive processes in tufa systems and their preservation potential in the stratigraphic record. The tufa features a 12.2-m-high, semi-conical structure, perched in a waterfall at the confluence of the Los Quebrachitos stream and Cabana River, overlying crystalline basement rocks rich in marble belts. The main lithofacies identified are: biohermal tufa, laminated tufa crusts, sandy tufa. Additionally, rubble tufa deposits occur at the base of the waterfall. Biohermal tufas are dominated by phytohermal components and associated invertebrate remains, with irregular clotted-micrite and peloidal fabrics. At the microscale, microbial activity becomes more significant, where cyanobacteria, diatoms, and exopolymeric substances contribute to the development of irregular laminated fabrics. Laminated tufa crusts consist of alternating micritic, microsparitic, and sparitic low-Mg calcite layers. The Los Quebrachitos stream, classified as fresh (total dissolved solids between 81.57 and 79.5 mg/L), slightly alkaline (pH between 7.9 and 8.3) waters, has a calcium-bicarbonate composition (Ca²⁺ between 23.10 and 26.16 mg/L, carbonate alkalinity between 95.95 and 112.18 mg/L). Flow rate variations, due to rainfall, appear to control the carbonate saturation state of waters in the Los Quebrachitos system. During dry season, the combined effects of aeration, low pressure, and jet flow enhance CO₂ degassing, enabling slightly saturated conditions with respect to calcite (Ω_cal = 1.1), promoting tiny water droplets evaporation, and thereby, inducing calcite precipitation. Conversely, increased rainfall dilutes water, reducing total dissolved solids and calcite saturation. Currently, the tufa system is in a destructive phase, showing gravitational collapse, bio-fracturing from tree root colonization, and surface erosion-dissolution features. The ongoing destructive processes seem to exceed the precipitation rates in this depleted carbonate system, mainly due to changes in climate conditions.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"486 ","pages":"Article 106931"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144589079","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}

{"title":"Abrupt changes in continental sedimentation triggered by monsoon-type event during EECO hyperthermals, Minervois Basin, Southern France","authors":"Cindy BOYRIE ,&nbsp;Flavia GIRARD ,&nbsp;Johan YANS ,&nbsp;Grégory BALLAS ,&nbsp;Fabrice LIHOREAU ,&nbsp;Mouloud BENAMMI ,&nbsp;Hélène BOURGET ,&nbsp;Géraldine GARCIA ,&nbsp;Christine LEREDDE ,&nbsp;Aimée PELLISSIER-TANON ,&nbsp;Xavier VALENTIN ,&nbsp;Dominique VIDALENC ,&nbsp;Rodolphe TABUCE","doi":"10.1016/j.sedgeo.2025.106923","DOIUrl":"10.1016/j.sedgeo.2025.106923","url":null,"abstract":"<div><div>Recent studies on Early Eocene climate have established that global climatic warming, characterized by negative carbon isotopic excursions (CIE, hyperthermals) in the atmosphere, are responsible for drastically changes in the terrestrial sedimentary record of sub-tropical basins. Here we present a key sedimentary record to understand geological and climatological changes in order to evaluate the impact of hyperthermals on sediment transport and deposition in continental setting during the Early Eocene Climatic Optimum (EECO) in Europe. Based on an integrative study combining sedimentology, sequential stratigraphy, magnetostratigraphy and chemostratigraphy (carbon isotopes, δ¹³C_org), the study proposes a detailed constrained chronostratigraphic framework of continental sedimentary series of the Minervois Basin (South of France). Using facies association analysis, the sedimentary succession is divided into three continental sequences bounded by subaerial unconformity deposited through the development of an endoreic underfilled basin. The sequences are composed of floodplain to palustrine-shallow lacustrine carbonate deposits reflecting arid climatic conditions during the EECO. They are cyclically punctuated by the sudden arrival of detrital fluxes with deposits of supercritical bedforms associated to an ephemeral multistorey braided channel plain, reflecting intense and extreme rainfall events in the hinterland. The latter coincides to CIEs corresponding to hyperthermals identified as C24n.1nH1/K (ETM3), C23rH2 (M), and C23n.2nH1-C23n.2nH2 (N<img>O) interval. Extreme monsoon-type events triggered by intense warm-ups during hyperthermals are proposed to explain sudden detrital inputs in the basin. This work confirms that transient hyperthermals can generate drastic hydrological changes in the sedimentary record.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"486 ","pages":"Article 106923"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518051","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}

{"title":"Clay mineral authigenesis as an example of organomineralization in Paleozoic coated grains and peloids","authors":"Stanislava Vodrážková ,&nbsp;Magdalena Koubová ,&nbsp;Axel Munnecke ,&nbsp;Tomáš Kumpan ,&nbsp;Radek Vodrážka ,&nbsp;Ondřej Pour ,&nbsp;Jiří Frýda","doi":"10.1016/j.sedgeo.2025.106912","DOIUrl":"10.1016/j.sedgeo.2025.106912","url":null,"abstract":"<div><div>The formation of clay minerals in marine environments, referred to as reversed weathering, represents an important process significantly affecting seawater chemistry. In this study, we describe organomineralization represented by clay mineral authigenesis associated with remnants of carbonaceous microstructures, interpreted as extracellular polymeric substances (EPS), from Silurian, Devonian, and Carboniferous coated grains (ooids, oncoids, and cortoids) and peloids (micritized grains). Multiple lines of evidence support the authigenic origin of these clay minerals: (1) Systematic spatial relationships with organic templates demonstrated through BSE imaging and elemental mapping; (2) Consistent qualitative elemental compositions across samples of varying ages, depositional settings, and burial histories; (3) Systematic textural, morphological, and compositional differences from detrital clay minerals, including filamentous texture, diffuse irregular boundaries, and higher Mg/(Al + Mg) and Si/(Si + Al) ratios; (4) XRD identification of authigenic I/S R3 with a diagnostic 1Md polytype structure; and (5) Consistency with the well-documented association of authigenic clay minerals with microbial surfaces, as evidenced by numerous laboratory experiments.</div><div>The documentation of authigenic clays associated with microbial structures in these common constituents of carbonate rocks suggests a potentially significant impact on element sequestration at the sediment-water interface and in the pore-water environment. We conclude that when properly contextualized, authigenic clay minerals can serve as indicators of former microbial surfaces.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"484 ","pages":"Article 106912"},"PeriodicalIF":2.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144243448","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}

{"title":"Quantitative reconstruction of paleowind strength based on ancient marine longshore bars: A case study of the Pinghu Formation in Pingbei slope zone, Xihu Sag","authors":"Jinlin Chen ,&nbsp;Junhui Wang ,&nbsp;Guofeng Yin ,&nbsp;Yang Wu ,&nbsp;Zhengming Dai ,&nbsp;Yonglin Li ,&nbsp;Jinhao Ma ,&nbsp;Zaixing Jiang ,&nbsp;Jie Xu","doi":"10.1016/j.sedgeo.2025.106903","DOIUrl":"10.1016/j.sedgeo.2025.106903","url":null,"abstract":"<div><div>Paleowind is an important paleoclimate parameter, but its study has been limited due to the lack of research methods. Recently, some researchers have proposed a method combining wind fields, waves, and the scale of ancient bar sand bodies to indirectly reconstruct paleowind. However, this method can only be used in lacustrine environments since in existing reconstruction methods, the fetch—a necessary parameter approximating the distance that wind blows—is difficult to obtain in marine environments. This study introduces the concept of “fully developed waves”, eliminating the need of fetch, which improves the current method of reconstructing paleowind using bars and extends its application to marine environments. The method is easy to operate and it only needs two parameters: the thickness of longshore bars and the seabed slope. This study further focuses on the bars of the Pinghu Formation in the Pingbei slope zone of the Xihu Sag within the East China Sea Shelf Basin. Using the proposed method, the paleowind variations during the depositional period (37.2–35.5 Ma) were reconstructed. The results show that the Xihu Sag was primarily influenced by easterly winds during this time, with wind speeds ranging from 8.76 to 19.71 m/s. This method removes the limitation of using bars for quantitative paleowind reconstruction exclusively in lacustrine settings, thereby enhancing its application potential and contributing to providing more data for paleoclimate reconstruction.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"484 ","pages":"Article 106903"},"PeriodicalIF":2.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221429","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}

{"title":"Holocene seismically induced soft-sediment deformation structures in the Qingshuihe Basin, northeastern Tibetan Plateau","authors":"Ting Huang ,&nbsp;Zhenhong Li ,&nbsp;Xiaopeng Dong ,&nbsp;Zhonghai Wu ,&nbsp;Linlin Kou ,&nbsp;Fang Wu","doi":"10.1016/j.sedgeo.2025.106902","DOIUrl":"10.1016/j.sedgeo.2025.106902","url":null,"abstract":"<div><div>This study focuses on the extensive development of soft-sediment deformation structures (SSDS) within the Holocene fluvial-lacustrine strata in the central and southern Qingshuihe Basin, located on the northeastern margin of the Tibetan Plateau. Through basin-wide sedimentological analysis, the study systematically examines the development characteristics, formation mechanisms, and triggering factors of SSDS across various sedimentary facies, while also exploring their relationship with regional seismic events.</div><div>The results reveal that a wide variety of SSDS are present in the basin, including small-scale faults, pseudofaults, load structures, water-escape structures, clastic dikes, deformed laminations, tension veins, and mixed accumulations. Most SSDS occur alongside syn-sedimentary faults (small-scale faults or pseudofaults) and exhibit significant directional features. SSDS in fluvial facies are more prominent than those in lacustrine facies, with the former displaying clear stratification, while the latter shows multi-phase deformation. Both fluvial and lacustrine SSDS are closely correlated in stratigraphic position and formation age with tension veins observed in loess deposits on the western side of the basin. Furthermore, the intensity of deformation exhibits a significant negative correlation with the distance from boundary faults. Most SSDS display characteristics of liquefaction, fluidization, and brittle deformation, consistent with seismic shaking.</div><div>Radiocarbon dating of 35 samples and optically stimulated luminescence (OSL) dating of 7 samples indicate that the SSDS in the southern part of the basin (6220 ± 95 a BP to 717 ± 24 a BP) are strongly associated with three major seismic events along the Haiyuan-Liupan Mountain Fault (a paleo-earthquake from 6600 ± 500 a BP to 5640 ± 540 a BP, the 1219 Guyuan M7 earthquake, and the 1306 Guyuan M7 earthquake). Meanwhile, SSDS in the central basin (11,270 ± 1100 a BP to 7728 ± 36 a BP) likely reflect three significant seismic events along the southeastern segment of the Xiangshan-Tianjingshan fault (XS-TJSF). These earthquakes are estimated to have magnitudes ranging from 6.5 to 7.3, with epicenters located in the central region of the southeastern segment of the XS-TJSF.</div><div>This study refines the criteria for identifying earthquake-induced SSDS and provides critical evidence for reconstructing the regional paleo-seismic history, thereby enhancing the understanding of the complex tectonic activity in the area.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"484 ","pages":"Article 106902"},"PeriodicalIF":2.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169788","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}

{"title":"Origin and paleoenvironmental significance of ooids in South China during the Early Triassic hyperthermal climates","authors":"Mengqing Ye ,&nbsp;Bolin Zhang ,&nbsp;Peng Zhu ,&nbsp;Xia Wang ,&nbsp;Xianguo Lang ,&nbsp;Fengcun Xing ,&nbsp;Jingjing Liu","doi":"10.1016/j.sedgeo.2025.106901","DOIUrl":"10.1016/j.sedgeo.2025.106901","url":null,"abstract":"<div><div>The Early Triassic was a crucial period for biotic recovery immediately after the end-Permian mass extinction, with widespread development of ooid deposits around the world. However, two competing hypotheses regarding the inorganic or organic origins of ooids remain under debate. Here, we focus on the Lower Triassic Yelang Formation in the Yunfeng section of Guizhou Province and conduct sedimentological and geochemical analyses, combined with statistical analysis of ooid size and morphology, to reveal the origin of ooids and explore their formation in relation to extreme environmental changes. Our results show that hydrodynamic conditions and microbial activities are key factors influencing ooid formation. The evolution of sedimentary facies, changes in ooid size and types, and variations in ooid morphology and sorting all suggest that stronger hydrodynamic conditions favor ooid formation, leading to more abundant and larger ooid deposits. Low δ¹⁵N values (average +1.51 ‰) suggest flourishing microbes dominated by photoautotrophic nitrogen-fixing cyanobacteria, while the C/N vs. Δ¹³C_carb-org crossplot indicates a significant contribution from eukaryotic algae. Furthermore, microstructural evidence of microbial remains and borings in ooids indicates both constructive and destructive roles of these microbes in their formation. Abundant filamentous microbial fossils and nanograin aggregates observed in ooids also provide direct evidence of biogenic signatures intrinsically related to organomineralization. A comprehensive biochemical model of ooid formation is proposed here, involving microbial-induced mineralization and biomediated carbonate precipitation. In addition, we suggest that the combined effects of exacerbated marine anoxia and extreme hyperthermal climates contributed to the widespread development of ooids during the Early Triassic.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"483 ","pages":"Article 106901"},"PeriodicalIF":2.7,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138759","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}

{"title":"Impact of secondary geomorphic processes on sedimentary characteristics of alluvial fans: Implications for reservoir exploration and development","authors":"Zixiao Peng ,&nbsp;Jianhua Qu ,&nbsp;En Xie ,&nbsp;Chunqiang Chen ,&nbsp;Bang Zeng ,&nbsp;Dancheng Zhu ,&nbsp;Zhenghong Zhang","doi":"10.1016/j.sedgeo.2025.106892","DOIUrl":"10.1016/j.sedgeo.2025.106892","url":null,"abstract":"<div><div>Alluvial fans, typically characterized by a mixture of fine- and coarse-grained materials, high heterogeneity, and weakly structured organization, are formed through various depositional processes. Fan deposits are considered valuable reservoir exploration targets in the hydrocarbon field worldwide. A series of Quaternary fans in northwestern and northern China, subjected to secondary geomorphological processes of varying degrees, were analyzed. Primary geomorphic processes, characterized by lobe or sheet elements of debris flow, hyperconcentrated flow and sheet floods deposits, generally represent rapid fan aggradation and dominate the sedimentary succession of these fans. Deposition of secondary processes is mainly developed by streamflows reworking with identifiable features, such as sheet-like lag, braided/point bar, and channel elements. A lack of sediment input to the fan and the redistribution and remodification of the primary deposits characterize this process. Synsedimentary reservoir quality is significantly improved by reorganizing sorting, support styles, and bedding structures. The proportion of primary and secondary architectural elements is proposed to evaluate the relative intensity of secondary processes experienced by alluvial fans. The dominant drivers of strong secondary processes are attributed to frequent streamflow events in response to climate changes on millennial timescales. Physical properties and connectivity of alluvial fan reservoirs related to secondary processes are commonly improved compared to reservoirs directly originating from primary processes, as a deep-time example from the Karamay oilfield. The results of this study provide new insights into constructing alluvial fan models in deep-time terrestrial basins and contribute to predicting favorable reservoir distribution and adjusting development strategies for alluvial fan reservoirs worldwide.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"483 ","pages":"Article 106892"},"PeriodicalIF":2.7,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931367","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}

{"title":"Gastropod-rich lacustrine carbonate deposits in N Iberia: a depositional, climatic and ecological record of the Late Miocene","authors":"Zuriñe Larena ,&nbsp;Concha Arenas ,&nbsp;Josep Sanjuan ,&nbsp;Ana Pascual ,&nbsp;Mariano Larraz ,&nbsp;Xabier Murelaga ,&nbsp;Juan Ignacio Baceta","doi":"10.1016/j.sedgeo.2025.106899","DOIUrl":"10.1016/j.sedgeo.2025.106899","url":null,"abstract":"<div><div>The Tortonian Peña Adrian Formation represents the youngest depositional unit of the Miranda-Trebiño basin (Basque-Cantabrian Pyrenees), which developed on the Southern Basque-Cantabrian Pyrenees from late Eocene to Late Miocene times. The formation is a 50–160 m thick succession of alluvial detrital grading to lacustrine carbonates that contain rich and varied calcareous fossil biota (gastropods, ostracods and charophytes). The fossil association characterizes warm temperate, shallow lakes with vegetated bottoms and well‑oxygenated and alkaline fresh waters. Integration of stratigraphic, sedimentological, paleontological and C<img>O stable isotopic data allows the differentiation of a wide range of sedimentary facies, the construction of a depositional model and the definition of distinct evolutionary phases and relation to allogenic processes. Up to 3 metre-thick facies sequences record repetitive water-level changes, likely reflecting short-term climate changes. Overall, the succession outlines an asymmetric cycle of gradual expansion and faster contraction of a shallow ramp-like lake system evolving under oscillating climatic conditions. C and O stable isotopes are consistent with decreasing salinity and increasing precipitation/evaporation balance trough time. Excellent preservation of aragonitic and bimineralic gastropods characterizes the open lacustrine deposits, whereas shell dissolution and neomorphism are distinct in the palustrine ones. This contrasting degree of preservation of calcareous biota clearly reflects changes in the physico-chemical conditions that prevailed during sedimentation and early burial. The findings add to the knowledge of carbonate lake basins, help discern the factors that controlled their evolution and highlight specific depositional and preservation conditions for gastropod-rich carbonate records.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"483 ","pages":"Article 106899"},"PeriodicalIF":2.7,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144167723","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}

{"title":"Sequence architecture of a Miocene marginal shelf sea influenced by tectonic activity: A case study of Eastern Yinggehai Basin, South China Sea","authors":"Zhen Wang ,&nbsp;Benzhong Xian ,&nbsp;Qian Ma ,&nbsp;Caiwei Fan ,&nbsp;Jianping Liu ,&nbsp;Qianran Wu ,&nbsp;Rongheng Tian ,&nbsp;Hui Li ,&nbsp;Ximeng Zhang ,&nbsp;Wenmiao Zhang","doi":"10.1016/j.sedgeo.2025.106879","DOIUrl":"10.1016/j.sedgeo.2025.106879","url":null,"abstract":"<div><div>While sequence stratigraphic frameworks of passive continental margins have been extensively studied, their counterparts in semi-enclosed marginal shelf seas remain poorly understood. This study investigates the sequence architecture and depositional patterns of a marginal shelf sea system through integrated analysis of 3D seismic, well-log, and core data from the Miocene succession in the Yinggehai Basin, South China Sea. The Miocene strata were subdivided into seven third-order sequences whose architectures and sedimentary associations were governed by the interplay between slope-break geometries, sea-level fluctuations, and sediment supply. Three distinct shelf sequence types (A1, A2, and B) were recognized based on spatial configurations of slope breaks and relative sea-level positions. Type A1 sequence (Huangliu Formation and Mei1 Member) consists of multiple slope breaks at basin margins and in the interior basin, with sea-level falls exceeding the elevation of interior slope breaks. The sequence preserves complete systems tracts, including early lowstand (gravity flow-dominated), late lowstand, transgressive, and highstand tracts. In contrast, Type A2 sequence (Mei2 Member), though retaining multiple slope breaks, lacks early lowstand systems tracts due to insufficient sea-level fall to expose interior slope breaks. Type B sequence (Sanya Formation) features solely basin-margin fault-controlled slope breaks and shares systems tract compositions with Type A2. Sedimentary processes vary markedly among sequence types. Type A1 sequence hosts multi-phase, large-scale gravity flow deposits encompassing submarine fans, slope-perpendicular channels, and slope-parallel channels, with maximum development during early lowstand conditions. Type A2 sequence is characterized by braided river deltas interfingering with shelf mudstones, accompanied by limited gravity flow activity. Type B sequence comprises shallow marine facies and small-scale braided deltas. Hydrocarbon implications emerge from the preferential occurrence of reservoir-quality gravity flow sands in Type A1 lowstand systems tracts, while regional seals and source rocks are associated with shelf mudstones in Type A2 and B sequences. The sequence evolution is primarily controlled by <em>syn</em>-depositional tectonics (fault reactivation, post-rift subsidence) and semi-enclosed paleogeomorphology, secondarily by sediment influx and eustasy. This framework advances predictive models for shelf-scale sequence development in restricted marine settings and provides critical insights for global hydrocarbon exploration in analogous basins.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"482 ","pages":"Article 106879"},"PeriodicalIF":2.7,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807564","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}