Pub Date : 2026-01-01Epub Date: 2025-10-09DOI: 10.1016/j.marpetgeo.2025.107614
C.K. Mishra , P. Dewangan , G. Sriram , P.A. Mohammed Masood , S.K. Arun
Gas hydrates have been identified in the Cauvery-Mannar Basin, a passive rift setting largely devoid of recent tectonic activity as evidenced by seismic data. This study provides novel insights into gas migration pathways from deep-seated reservoirs to the shallow subsurface, with particular emphasis on the role of seismic chimneys as focused conduits for fluid and gas transport. The Bottom Simulating Reflector (BSR), a key seismic indicator of gas hydrates, is observed intermittently across multiple seismic profiles, underlain by extensive gas-charged sediments. A prominent feature in one of the seismic profile is a chimney-like structure, ∼650 m tall and 1000 m wide, originating from deeper gas-rich strata at depth. Formed through overpressure-induced hydrofracturing, the chimney acts as a conduit for vertical gas migration from deep-seated gas reservoirs to the Gas Hydrate Stability Zone (GHSZ). At the base of GHSZ, hydrates form impermeable layers that restrict vertical migration of free gas and promote lateral migration. Amplitude variation with angle (AVA) analysis reveals strong Class III anomalies in the updip direction of BSR, indicating preferential lateral gas migration along the base of GHSZ. Class IV anomalies observed in the updip region may signify high-concentration gas hydrates or fracture-filled deposits formed through focused gas accumulation. In this tectonically quiescent setting, hydrostatic pressure gradient drives both vertical and lateral gas migration, transporting gas from deep reservoirs to the shallow subsurface in the Mannar basin. These findings have important implications for understanding gas hydrate systems in other passive continental margin environments.
{"title":"Seismic chimneys as gas migration pathways and their role in hydrate accumulation: AVA insights from the Cauvery-mannar basin","authors":"C.K. Mishra , P. Dewangan , G. Sriram , P.A. Mohammed Masood , S.K. Arun","doi":"10.1016/j.marpetgeo.2025.107614","DOIUrl":"10.1016/j.marpetgeo.2025.107614","url":null,"abstract":"<div><div>Gas hydrates have been identified in the Cauvery-Mannar Basin, a passive rift setting largely devoid of recent tectonic activity as evidenced by seismic data. This study provides novel insights into gas migration pathways from deep-seated reservoirs to the shallow subsurface, with particular emphasis on the role of seismic chimneys as focused conduits for fluid and gas transport. The Bottom Simulating Reflector (BSR), a key seismic indicator of gas hydrates, is observed intermittently across multiple seismic profiles, underlain by extensive gas-charged sediments. A prominent feature in one of the seismic profile is a chimney-like structure, ∼650 m tall and 1000 m wide, originating from deeper gas-rich strata at depth. Formed through overpressure-induced hydrofracturing, the chimney acts as a conduit for vertical gas migration from deep-seated gas reservoirs to the Gas Hydrate Stability Zone (GHSZ). At the base of GHSZ, hydrates form impermeable layers that restrict vertical migration of free gas and promote lateral migration. Amplitude variation with angle (AVA) analysis reveals strong Class III anomalies in the updip direction of BSR, indicating preferential lateral gas migration along the base of GHSZ. Class IV anomalies observed in the updip region may signify high-concentration gas hydrates or fracture-filled deposits formed through focused gas accumulation. In this tectonically quiescent setting, hydrostatic pressure gradient drives both vertical and lateral gas migration, transporting gas from deep reservoirs to the shallow subsurface in the Mannar basin. These findings have important implications for understanding gas hydrate systems in other passive continental margin environments.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107614"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-09DOI: 10.1016/j.marpetgeo.2025.107620
Louison Mercier , Sébastien Migeon , Jean-Loup Rubino , Yamirka Rojas-Agramonte , Anna Hagen , Romain Bousquet , Regina Mertz-Kraus
Submarine canyons are key elements of the evolution of convergent margins. Their infilling can be mud-prone and thus represents a good seal if they cut through reservoir series, this erosion phase may be enhanced by tectonic activity. The present study focuses on the Western Alpine Foreland Basin where we use the outcrops of the Schistes à Blocs Formation to study the syn-tectonic evolution of a Lower Oligocene submarine canyon that cuts through the Annot Sandstones Formation. The Intra Schistes à Blocs Erosion Surface (ISaBES) has been mapped in the field. Airborne and drone pictures were also used. Moreover, the deposition model and the stratigraphic architecture of the canyon-fill were reconstructed from the analysis of seven sedimentary logs cumulating 410 m of series, particularly crossing the under described Schistes Bruns Member. The sedimentary system of this lower unit of the canyon-fill has been also constrained by the measurement of paleocurrents, and the provenance analysis of detrital zircons from four samples. The paleocurrent measurements on the unidirectional ripples deposited within the Schistes Bruns Member is witness of a turbulent flow rebound against the steep northern flank of the canyon, during the construction of internal levees which often experimented gravity collapse. Slumping of internal levees improves the seal properties of the canyon-fill, while the canyon thalweg was dominated by by-pass processes. Detrital zircons reveal that the provenance of the Schistes Bruns Member is sourced by the same sedimentary system of the Annot Sandstones Formation. Thus, we interpreted that both the canyon excavation and the sediment by-pass within its thalweg during the deposition of the Schistes Bruns Member, were triggered by an increase in basin slope related to the tectonic evolution of the accretionary prism. Finally, the ISaBES is a composite and diachronous surface resulting both from the morphology of the internal levees, and from their reworking during the deposition of the olistostromes of the Schistes à Blocs Exotiques Member, that predates the emplacement of the Alpine nappes within the foreland basin.
{"title":"A mud-filled submarine canyon cutting through a sand-prone turbidite succession: A Lower Oligocene field analogue of stratigraphic-structural trap in the Western Alpine Foreland Basin, France","authors":"Louison Mercier , Sébastien Migeon , Jean-Loup Rubino , Yamirka Rojas-Agramonte , Anna Hagen , Romain Bousquet , Regina Mertz-Kraus","doi":"10.1016/j.marpetgeo.2025.107620","DOIUrl":"10.1016/j.marpetgeo.2025.107620","url":null,"abstract":"<div><div>Submarine canyons are key elements of the evolution of convergent margins. Their infilling can be mud-prone and thus represents a good seal if they cut through reservoir series, this erosion phase may be enhanced by tectonic activity. The present study focuses on the Western Alpine Foreland Basin where we use the outcrops of the Schistes à Blocs Formation to study the syn-tectonic evolution of a Lower Oligocene submarine canyon that cuts through the Annot Sandstones Formation. The Intra Schistes à Blocs Erosion Surface (ISaBES) has been mapped in the field. Airborne and drone pictures were also used. Moreover, the deposition model and the stratigraphic architecture of the canyon-fill were reconstructed from the analysis of seven sedimentary logs cumulating 410 m of series, particularly crossing the under described Schistes Bruns Member. The sedimentary system of this lower unit of the canyon-fill has been also constrained by the measurement of paleocurrents, and the provenance analysis of detrital zircons from four samples. The paleocurrent measurements on the unidirectional ripples deposited within the Schistes Bruns Member is witness of a turbulent flow rebound against the steep northern flank of the canyon, during the construction of internal levees which often experimented gravity collapse. Slumping of internal levees improves the seal properties of the canyon-fill, while the canyon thalweg was dominated by by-pass processes. Detrital zircons reveal that the provenance of the Schistes Bruns Member is sourced by the same sedimentary system of the Annot Sandstones Formation. Thus, we interpreted that both the canyon excavation and the sediment by-pass within its thalweg during the deposition of the Schistes Bruns Member, were triggered by an increase in basin slope related to the tectonic evolution of the accretionary prism. Finally, the ISaBES is a composite and diachronous surface resulting both from the morphology of the internal levees, and from their reworking during the deposition of the olistostromes of the Schistes à Blocs Exotiques Member, that predates the emplacement of the Alpine nappes within the foreland basin.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107620"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-15DOI: 10.1016/j.marpetgeo.2025.107639
Samy K. Moawad , Adel R. Moustafa , Hany M. Helmy
Previous studies of the Gulf of Suez rift show a main subsidence phase in the Burdigalian during deposition of the lower Rudeis Formation followed by slow subsidence afterwards. By contrast, the southern part of the rift shows continued deformation and subsidence since the Late Miocene evidenced by continued faulting as well as deposition of larger thicknesses of the Upper Miocene evaporites and post-Miocene sediments. Present-day deformation is manifested by recent seismicity in the southern part of the rift as well as faulting of the seabed forming a deepwater area. Additional extension in the southern part of the rift is attributed to the effect of the nearby Dead Sea Transform. This led to increased crustal thinning and higher heat flow, causing more maturation of the hydrocarbon source rocks indicated by high API gravity oil with the presence of a primary gas cap. Continued extension in the nearby northern Red Sea area is expected to lead to higher magnitudes of heat flow. This would enhance the maturation of hydrocarbon source rocks, turning the Red Sea marginal basins into potential gas or gas/light oil provinces. This study provides new considerations for the tectonic history of the southern Gulf of Suez rift that influences the petroleum system evaluation both in the southern Gulf of Suez and the northern Red Sea basins.
{"title":"Superposed deformation in the southern gulf of Suez rift and impact on hydrocarbon maturation","authors":"Samy K. Moawad , Adel R. Moustafa , Hany M. Helmy","doi":"10.1016/j.marpetgeo.2025.107639","DOIUrl":"10.1016/j.marpetgeo.2025.107639","url":null,"abstract":"<div><div>Previous studies of the Gulf of Suez rift show a main subsidence phase in the Burdigalian during deposition of the lower Rudeis Formation followed by slow subsidence afterwards. By contrast, the southern part of the rift shows continued deformation and subsidence since the Late Miocene evidenced by continued faulting as well as deposition of larger thicknesses of the Upper Miocene evaporites and post-Miocene sediments. Present-day deformation is manifested by recent seismicity in the southern part of the rift as well as faulting of the seabed forming a deepwater area. Additional extension in the southern part of the rift is attributed to the effect of the nearby Dead Sea Transform. This led to increased crustal thinning and higher heat flow, causing more maturation of the hydrocarbon source rocks indicated by high API gravity oil with the presence of a primary gas cap. Continued extension in the nearby northern Red Sea area is expected to lead to higher magnitudes of heat flow. This would enhance the maturation of hydrocarbon source rocks, turning the Red Sea marginal basins into potential gas or gas/light oil provinces. This study provides new considerations for the tectonic history of the southern Gulf of Suez rift that influences the petroleum system evaluation both in the southern Gulf of Suez and the northern Red Sea basins.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107639"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-14DOI: 10.1016/j.marpetgeo.2025.107647
Mariana I. Olariu, Nikhil Sharma, Vann Smith, Maria Antonieta Lorente, Lorena Moscardelli
Understanding how climatically-driven changes can produce significant sea level fluctuations, especially during periods of Earth's history that lacked continental-scale ice sheets remains a key geological question. We use an example from the Paleocene Lower Wilcox greenhouse time to illustrate how climatically-influenced short-term (100–400 kyr) sea-level changes controlled sedimentary deposition. Our interpretations are based on a geochemical proxy model for greenhouse humid–arid climatic shifts and on palynological analysis. Provenance tracers in the studied Lower Wilcox section (∼3 Myr) indicate that the average source composition remained steady, suggesting that variations observed in cores could have been mainly driven by climate. During the humid greenhouse phases, enhanced weathering and precipitation likely increased sediment supply and promoted progradation of deltas. A higher influx of freshwater during humid intervals might have favored the development of coastal marshy conditions characterized by the presence of the fern spore Deltoidospora. Arid greenhouse phases appear to correspond to diminished sediment input and shoreline retreat. The presence of Classopollis, a pollen produced by plants of the extinct Cheirolepidiaceae, is indicative of arid coastal salt marshes and generally higher abundances of Classopollis in the Selandian core sections may suggest more arid conditions.
Repetitive 4th order regressive-transgressive cycles and modest facies belt shifts are observed in cores from two wells. Subsurface sandstone mapping reflects short excursions of the shoreline during repeated cross shelf transits amid an overall backstepping 3rd order depositional sequence. We interpret these as potentially reflecting climatically modulated changes, though we recognize the limitations and uncertainties associated with interpreting weathering signals from marginal marine deposits. A multiproxy approach strengthens the case for climate-related influences on short-term sea-level dynamics.
{"title":"Short-term climatic perturbations in the Paleocene Lower Wilcox","authors":"Mariana I. Olariu, Nikhil Sharma, Vann Smith, Maria Antonieta Lorente, Lorena Moscardelli","doi":"10.1016/j.marpetgeo.2025.107647","DOIUrl":"10.1016/j.marpetgeo.2025.107647","url":null,"abstract":"<div><div>Understanding how climatically-driven changes can produce significant sea level fluctuations, especially during periods of Earth's history that lacked continental-scale ice sheets remains a key geological question. We use an example from the Paleocene Lower Wilcox greenhouse time to illustrate how climatically-influenced short-term (100–400 kyr) sea-level changes controlled sedimentary deposition. Our interpretations are based on a geochemical proxy model for greenhouse humid–arid climatic shifts and on palynological analysis. Provenance tracers in the studied Lower Wilcox section (∼3 Myr) indicate that the average source composition remained steady, suggesting that variations observed in cores could have been mainly driven by climate. During the humid greenhouse phases, enhanced weathering and precipitation likely increased sediment supply and promoted progradation of deltas. A higher influx of freshwater during humid intervals might have favored the development of coastal marshy conditions characterized by the presence of the fern spore <em>Deltoidospora</em>. Arid greenhouse phases appear to correspond to diminished sediment input and shoreline retreat. The presence of <em>Classopollis,</em> a pollen produced by plants of the extinct Cheirolepidiaceae, is indicative of arid coastal salt marshes and generally higher abundances of <em>Classopollis</em> in the Selandian core sections may suggest more arid conditions.</div><div>Repetitive 4th order regressive-transgressive cycles and modest facies belt shifts are observed in cores from two wells. Subsurface sandstone mapping reflects short excursions of the shoreline during repeated cross shelf transits amid an overall backstepping 3rd order depositional sequence. We interpret these as potentially reflecting climatically modulated changes, though we recognize the limitations and uncertainties associated with interpreting weathering signals from marginal marine deposits. A multiproxy approach strengthens the case for climate-related influences on short-term sea-level dynamics.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107647"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145620208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-09-29DOI: 10.1016/j.marpetgeo.2025.107613
E. Luzzi , M. D'Emidio , L. Macelloni
Brine pools are underwater hypersaline and often anoxic lakes, which occur abundantly in the Gulf of America (Gulf) due to its complex geological and structural setting, particularly because of the presence of the buried Louann salt deposit. Fluids migrating upward dissolve this salt, and the resulting brine ascends until it is expelled at the seafloor through cold seeps. In instances where the brine accumulates without significant overflow, brine pools are formed. These extreme environments host interconnected communities of bacteria and archaea, and at their edges, chemosynthetic communities thrive, forming extensive mussel beds. By studying the variable geochemical gradients and biological settings of the Gulf brine pools, researchers have significantly advanced our understanding of these extreme environments. However, due to the limited accessibility of these sites, brine pools remain understudied compared to more accessible locations, leaving many questions unanswered. This review synthesizes current knowledge of Gulf brine pools, providing a standardized foundation for future exploration, assessments of critical minerals, and research efforts, which could shed light on the habitability limits on our planet and inform the search for life in similar environments within our solar system.
{"title":"Brine pools in the Gulf of America: A review","authors":"E. Luzzi , M. D'Emidio , L. Macelloni","doi":"10.1016/j.marpetgeo.2025.107613","DOIUrl":"10.1016/j.marpetgeo.2025.107613","url":null,"abstract":"<div><div>Brine pools are underwater hypersaline and often anoxic lakes, which occur abundantly in the Gulf of America (Gulf) due to its complex geological and structural setting, particularly because of the presence of the buried Louann salt deposit. Fluids migrating upward dissolve this salt, and the resulting brine ascends until it is expelled at the seafloor through cold seeps. In instances where the brine accumulates without significant overflow, brine pools are formed. These extreme environments host interconnected communities of bacteria and archaea, and at their edges, chemosynthetic communities thrive, forming extensive mussel beds. By studying the variable geochemical gradients and biological settings of the Gulf brine pools, researchers have significantly advanced our understanding of these extreme environments. However, due to the limited accessibility of these sites, brine pools remain understudied compared to more accessible locations, leaving many questions unanswered. This review synthesizes current knowledge of Gulf brine pools, providing a standardized foundation for future exploration, assessments of critical minerals, and research efforts, which could shed light on the habitability limits on our planet and inform the search for life in similar environments within our solar system.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107613"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-10DOI: 10.1016/j.marpetgeo.2025.107651
Junjie Wang , Pengfei Zhang , Weizheng Gao , Panxue Li , Yangjian Yi , Chenxi Wu , Han Wu , Xinlin Song , Wenbiao Li , Guohui Chen , Nengwu Zhou , Chao Liu , Shuangfang Lu
Understanding the occurrence and enrichment mechanisms of shale oil is essential for the effective exploration of continental basins with complex reservoir characteristics. In this study, an integrated approach combining nuclear magnetic resonance (NMR) with fluid restoration techniques, Rock-Eval pyrolysis, total organic carbon (TOC) analysis, X-ray diffraction (XRD), crude oil composition analysis, and microscopic observation was used to investigate the shale in the Erennaoer Depression of the Erlian Basin. Based on the innovative in-situ fluid content characterization method, the shale micromigration characteristics were quantitatively analyzed by micromigrated hydrocarbons (ΔQ). The coupling relationship between shale pore fluid content, pore structure, and mineral composition was analyzed, elucidating the shale pore fluid occurrence mechanisms. Three dominant shale lithofacies, felsic-rich, felsic, and calcareous, were identified, with interparticle pores at quartz grain edges serving as the primary storage space. Shale oil occurrence is jointly governed by lithofacies, pore structure, and hydrocarbon micromigration. While most samples exhibit minimal micromigration (−200 mg/g TOC < ΔQ < 107 mg/g TOC), interlaminar redistribution is common. In organic-lean shales (TOC < 0.7 %), hydrocarbon generation capacity limits oil content, and no extra-micromigration occurs. In organic-rich shales (TOC >0.7 %), excess hydrocarbons are expelled and stored in interparticle pores of quartz laminae, with free oil content positively correlated with the development of meso- to macropores. Notably, felsic-rich shales with low clay content show evidence of intra-micromigration and preferential accumulation of light-saturated hydrocarbons (C14–C18), resulting in ΔQ < −200 mg/g TOC, OSI > 200 mg/g TOC, and Tmax < 425 °C. These hydrocarbons form multi-scale source–reservoir coupling systems through selective micromigration into adjacent quartz laminae and felsic-rich shale interbeds with low clay, while heavier fractions remain in organic-rich layers. These findings provide new insights into the spatial distribution of shale oil and identify favorable sweet spots in the Erlian Basin, offering a foundation for resource assessment and development strategies in similar shale oil basins.
{"title":"Shale oil in the Lower Cretaceous of the Erennaoer Depression, Erlian Basin: Insights from in-situ fluid content and hydrocarbon micromigration","authors":"Junjie Wang , Pengfei Zhang , Weizheng Gao , Panxue Li , Yangjian Yi , Chenxi Wu , Han Wu , Xinlin Song , Wenbiao Li , Guohui Chen , Nengwu Zhou , Chao Liu , Shuangfang Lu","doi":"10.1016/j.marpetgeo.2025.107651","DOIUrl":"10.1016/j.marpetgeo.2025.107651","url":null,"abstract":"<div><div>Understanding the occurrence and enrichment mechanisms of shale oil is essential for the effective exploration of continental basins with complex reservoir characteristics. In this study, an integrated approach combining nuclear magnetic resonance (NMR) with fluid restoration techniques, Rock-Eval pyrolysis, total organic carbon (TOC) analysis, X-ray diffraction (XRD), crude oil composition analysis, and microscopic observation was used to investigate the shale in the Erennaoer Depression of the Erlian Basin. Based on the innovative in-situ fluid content characterization method, the shale micromigration characteristics were quantitatively analyzed by micromigrated hydrocarbons (ΔQ). The coupling relationship between shale pore fluid content, pore structure, and mineral composition was analyzed, elucidating the shale pore fluid occurrence mechanisms. Three dominant shale lithofacies, felsic-rich, felsic, and calcareous, were identified, with interparticle pores at quartz grain edges serving as the primary storage space. Shale oil occurrence is jointly governed by lithofacies, pore structure, and hydrocarbon micromigration. While most samples exhibit minimal micromigration (−200 mg/g TOC < ΔQ < 107 mg/g TOC), interlaminar redistribution is common. In organic-lean shales (TOC < 0.7 %), hydrocarbon generation capacity limits oil content, and no extra-micromigration occurs. In organic-rich shales (TOC >0.7 %), excess hydrocarbons are expelled and stored in interparticle pores of quartz laminae, with free oil content positively correlated with the development of meso- to macropores. Notably, felsic-rich shales with low clay content show evidence of intra-micromigration and preferential accumulation of light-saturated hydrocarbons (C<sub>14</sub>–C<sub>18</sub>), resulting in ΔQ < −200 mg/g TOC, OSI > 200 mg/g TOC, and T<sub>max</sub> < 425 °C. These hydrocarbons form multi-scale source–reservoir coupling systems through selective micromigration into adjacent quartz laminae and felsic-rich shale interbeds with low clay, while heavier fractions remain in organic-rich layers. These findings provide new insights into the spatial distribution of shale oil and identify favorable sweet spots in the Erlian Basin, offering a foundation for resource assessment and development strategies in similar shale oil basins.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107651"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-30DOI: 10.1016/j.marpetgeo.2025.107648
Xiaobo Zheng , Hongtao Zhu , Sen Li , Haifeng Yang , Zhiwei Zeng , Zhongheng Sun
Lacustrine source-to-sink systems offer essential insights into sediment generation, transport, and deposition processes. However, the dynamics of ancient lacustrine source-to-sink systems, especially in rift basins, remain poorly understood due to limited well data. In this study, we use high-resolution 3D seismic data, supplemented by limited well information, to reconstruct the source-to-sink architecture and evolution on the southern slope of the Bozhong Depression, Bohai Bay Basin, China. The system consists of granite-dominated catchments, incised paleovalleys, and sedimentary fans that evolved from confined deltas to braided river deltas. Quantitative morphometric (e.g. fan area, catchment area, and catchment relief) analysis reveals a two-stage depositional evolution, driven by topographic slope variations and lake-level fluctuations. We identify two types of catchment-to-fan coupling, confined and unconfined, each reflecting distinct topographic and hydrodynamic controls. These findings refine our understanding of sediment routing in lacustrine rift basins and offer predictive value for reservoir characterization in similar tectonic settings.
{"title":"Seismic characterization of ancient lacustrine source-to-sink systems in a rift basin: The Bozhong Depression, Bohai Bay Basin, China","authors":"Xiaobo Zheng , Hongtao Zhu , Sen Li , Haifeng Yang , Zhiwei Zeng , Zhongheng Sun","doi":"10.1016/j.marpetgeo.2025.107648","DOIUrl":"10.1016/j.marpetgeo.2025.107648","url":null,"abstract":"<div><div>Lacustrine source-to-sink systems offer essential insights into sediment generation, transport, and deposition processes. However, the dynamics of ancient lacustrine source-to-sink systems, especially in rift basins, remain poorly understood due to limited well data. In this study, we use high-resolution 3D seismic data, supplemented by limited well information, to reconstruct the source-to-sink architecture and evolution on the southern slope of the Bozhong Depression, Bohai Bay Basin, China. The system consists of granite-dominated catchments, incised paleovalleys, and sedimentary fans that evolved from confined deltas to braided river deltas. Quantitative morphometric (e.g. fan area, catchment area, and catchment relief) analysis reveals a two-stage depositional evolution, driven by topographic slope variations and lake-level fluctuations. We identify two types of catchment-to-fan coupling, confined and unconfined, each reflecting distinct topographic and hydrodynamic controls. These findings refine our understanding of sediment routing in lacustrine rift basins and offer predictive value for reservoir characterization in similar tectonic settings.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107648"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145467356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-10DOI: 10.1016/j.marpetgeo.2025.107623
Eduardo Roemers-Oliveira , Sophie Viseur , François Fournier , Ítalo Gomes Gonçalves , Felipe Guadagnin , Guilherme Pederneiras Raja Gabaglia , Ednilson Bento Freire , Daniel Galvão Carnier Fragoso , Juan Ignacio Hernández , Ana Clara Freccia , Guilherme de Godoy Rangel
Digital Outcrop Models (DOMs), empowered by advanced digital techniques, have revolutionized the study of outcrop analogs for petroleum reservoir characterization by enabling the extraction of key quantitative parameters for modeling. The limited availability of subsurface data often constrains reservoir characterization, making outcrop analogs essential tools for improving geological models. The analogs bridge the gap between borehole-derived information and regional-scale seismic data, providing crucial mesoscale insights. In this context, this study proposes an integrative workflow combining high-resolution sequence stratigraphy (HRSS) with digital techniques to enhance the understanding of depositional settings and extract data from the Balbuena III Sequence of the Salta Basin, Argentina, a well-established stratigraphic basin analog for Brazilian pre-salt carbonate reservoirs. The workflow combines traditional field-based methods with advanced digital techniques applied to photogrammetric data, including Local Binary Pattern (LBP) analysis and Convolutional Neural Networks (CNNs). LBP analysis correlated with stratigraphic interpretation demonstrated promising potential for characterizing the high-frequency cyclicity observed in the study area. CNN-based segmentation classified and delineated eleven lithofacies, including carbonate, siliciclastic, mixed, and volcanic facies. This segmentation allows for the generation of lithofacies-classified 3D point clouds and a detailed spatial representation of facies distribution across the outcrop. Digital approaches enable more in-depth analysis by increasing efficiency, accuracy, and the capacity to analyze large datasets. By combining digital and traditional methods, this work improves the analysis of outcrop analogs, which contributes to more accurate geological modeling and enhances the predictive capability of petroleum fields and hydrocarbon recovery.
{"title":"Advanced digital techniques applied to outcrop models: Integrating Local Binary Pattern (LBP) and Convolutional Neural Network (CNN) to support stratigraphic and sedimentological interpretation of reservoir analogs in the Salta Basin, Argentina","authors":"Eduardo Roemers-Oliveira , Sophie Viseur , François Fournier , Ítalo Gomes Gonçalves , Felipe Guadagnin , Guilherme Pederneiras Raja Gabaglia , Ednilson Bento Freire , Daniel Galvão Carnier Fragoso , Juan Ignacio Hernández , Ana Clara Freccia , Guilherme de Godoy Rangel","doi":"10.1016/j.marpetgeo.2025.107623","DOIUrl":"10.1016/j.marpetgeo.2025.107623","url":null,"abstract":"<div><div>Digital Outcrop Models (DOMs), empowered by advanced digital techniques, have revolutionized the study of outcrop analogs for petroleum reservoir characterization by enabling the extraction of key quantitative parameters for modeling. The limited availability of subsurface data often constrains reservoir characterization, making outcrop analogs essential tools for improving geological models. The analogs bridge the gap between borehole-derived information and regional-scale seismic data, providing crucial mesoscale insights. In this context, this study proposes an integrative workflow combining high-resolution sequence stratigraphy (HRSS) with digital techniques to enhance the understanding of depositional settings and extract data from the Balbuena III Sequence of the Salta Basin, Argentina, a well-established stratigraphic basin analog for Brazilian pre-salt carbonate reservoirs. The workflow combines traditional field-based methods with advanced digital techniques applied to photogrammetric data, including Local Binary Pattern (LBP) analysis and Convolutional Neural Networks (CNNs). LBP analysis correlated with stratigraphic interpretation demonstrated promising potential for characterizing the high-frequency cyclicity observed in the study area. CNN-based segmentation classified and delineated eleven lithofacies, including carbonate, siliciclastic, mixed, and volcanic facies. This segmentation allows for the generation of lithofacies-classified 3D point clouds and a detailed spatial representation of facies distribution across the outcrop. Digital approaches enable more in-depth analysis by increasing efficiency, accuracy, and the capacity to analyze large datasets. By combining digital and traditional methods, this work improves the analysis of outcrop analogs, which contributes to more accurate geological modeling and enhances the predictive capability of petroleum fields and hydrocarbon recovery.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107623"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-09DOI: 10.1016/j.marpetgeo.2025.107637
Jochen Knies , Stephen Killops , Trond Brekke , Kari Grøsfjeld , Kasia K. Sliwinska , Sverre Planke , Carmen Gaina , Giuliana Panieri , Claudio Argentino , Ute Mann , Wiktor Bönke , Tomas Kjennerud , Rune Mattingsdal
This study evaluates the source rock potential, organic matter input, and depositional environments of Miocene-aged sediments in the eastern Nordic Seas. It focuses on ODP/IODP Sites 909, 985, and U1572, two exploration wells (7316/5-1 and 6608/10-1), and oil seeps offshore western Svalbard. Integrated marine palynological, biomarker, and geochemical analyses indicate a mainly Early to Middle Miocene age and a mixed terrestrial-marine origin of the sedimentary organic matter and associated oil seeps. Angiosperm-derived biomarkers, especially triterpenoids like oleananes and oleanenes, are abundant and help link seeping oils to deltaic terrestrial sources. Depositional settings ranged from oxic in the Fram Strait (Hole 909C) to dysoxic or anoxic in southern Sites (Holes 985A and U1572B), influenced by the semi-enclosed Nordic Seas. Geochemical indicators such as sulfur content, TOC/S ratios, and Pr/Ph values reflect variations in bottom water oxygenation and sediment conditions. Terrestrial organic input is linked to Miocene deltaic systems, likely formed by tectonic uplift in East Greenland, the Barents Sea, and central Norway.
Basin modeling in the southwestern Barents Sea, using seismic and well data, shows that Miocene source rocks have reached maturity levels sufficient for hydrocarbon generation, especially beneath thick Plio-Pleistocene glacial overburden. The presence of oleanene and oleanane in both boreholes and oil seeps supports the conclusion that these Miocene source rocks are regionally widespread and part of an active petroleum system.
{"title":"A prolific Tertiary source rock of terrestrial origin in the eastern Nordic Seas","authors":"Jochen Knies , Stephen Killops , Trond Brekke , Kari Grøsfjeld , Kasia K. Sliwinska , Sverre Planke , Carmen Gaina , Giuliana Panieri , Claudio Argentino , Ute Mann , Wiktor Bönke , Tomas Kjennerud , Rune Mattingsdal","doi":"10.1016/j.marpetgeo.2025.107637","DOIUrl":"10.1016/j.marpetgeo.2025.107637","url":null,"abstract":"<div><div>This study evaluates the source rock potential, organic matter input, and depositional environments of Miocene-aged sediments in the eastern Nordic Seas. It focuses on ODP/IODP Sites 909, 985, and U1572, two exploration wells (7316/5-1 and 6608/10-1), and oil seeps offshore western Svalbard. Integrated marine palynological, biomarker, and geochemical analyses indicate a mainly Early to Middle Miocene age and a mixed terrestrial-marine origin of the sedimentary organic matter and associated oil seeps. Angiosperm-derived biomarkers, especially triterpenoids like oleananes and oleanenes, are abundant and help link seeping oils to deltaic terrestrial sources. Depositional settings ranged from oxic in the Fram Strait (Hole 909C) to dysoxic or anoxic in southern Sites (Holes 985A and U1572B), influenced by the semi-enclosed Nordic Seas. Geochemical indicators such as sulfur content, TOC/S ratios, and Pr/Ph values reflect variations in bottom water oxygenation and sediment conditions. Terrestrial organic input is linked to Miocene deltaic systems, likely formed by tectonic uplift in East Greenland, the Barents Sea, and central Norway.</div><div>Basin modeling in the southwestern Barents Sea, using seismic and well data, shows that Miocene source rocks have reached maturity levels sufficient for hydrocarbon generation, especially beneath thick Plio-Pleistocene glacial overburden. The presence of oleanene and oleanane in both boreholes and oil seeps supports the conclusion that these Miocene source rocks are regionally widespread and part of an active petroleum system.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107637"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-12-03DOI: 10.1016/j.marpetgeo.2025.107653
Hyun Suk Lee , Soonmi Cho , Junghee Son , Gihun Song , Juhyeon Oh , Wonjun Kwak
{"title":"Corrigendum to “Chronostratigraphy and petrophysical properties for the middle to late Miocene sediments in the shelf to abyssal plain of the Ulleung Basin, Korea” [Mar. Petrol. Geol. 183 (2026) 107650]","authors":"Hyun Suk Lee , Soonmi Cho , Junghee Son , Gihun Song , Juhyeon Oh , Wonjun Kwak","doi":"10.1016/j.marpetgeo.2025.107653","DOIUrl":"10.1016/j.marpetgeo.2025.107653","url":null,"abstract":"","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"183 ","pages":"Article 107653"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145732853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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