Marine and Petroleum Geology最新文献

{"title":"Methanogenetic evolution of a buried pinnacle structure overlying a fluid-escape pipe in the Western Exmouth Plateau, Australia","authors":"Kamaldeen Olakunle L. Omosanya ,&nbsp;Muhedeen A. Lawal ,&nbsp;Yakufu Niyazi ,&nbsp;Ayomipo O. Bankole ,&nbsp;Ovie Emmanuel Eruteya","doi":"10.1016/j.marpetgeo.2025.107521","DOIUrl":"10.1016/j.marpetgeo.2025.107521","url":null,"abstract":"<div><div>The formation and evolution of carbonate pinnacles in sedimentary basins remain a subject of significant scientific interest, particularly in relation to their interaction with subsurface fluid migration. This study uses high-resolution three-dimensional (3D) seismic reflection data to investigate an isolated and buried carbonate pinnacle (∼700 m wide and 99 m high) in the Exmouth Plateau, offshore Australia. The pinnacle shows a cone-shaped morphology with internally admixed low- to moderate-amplitude seismic reflections and is spatially associated with an underlying vertical zone of low-amplitude and chaotic reflections, interpreted as a fluid-escape pipe. The presence of this pipe suggests focused vertical fluid migration from a potential deep-seated source, likely the early Triassic Locker Shale. Seismic onlap of overlying sediments on the pinnacle flanks precludes its interpretation as a seismic artifact, supporting its in situ origin. The observed structural and stratigraphic relationships indicate that episodic methane expulsion influenced pinnacle development, suggesting a methanogenetic origin. These findings provide added insights into the role of fluid migration in carbonate system evolution and have broader implications for understanding reservoir formation, diagenetic alteration, and subsurface fluid storage. Importantly, our study advances the geoscientific understanding of carbonate diagenesis and basin evolution in both modern and ancient settings by elucidating the interaction between fluid escape features and carbonate build-ups.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107521"},"PeriodicalIF":3.7,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490629","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":"Provenance, sedimentary paleoenvironment and organic matter accumulation mechanisms in shales from the Lower Cambrian Qiongzhusi Formation, SW Yangtze Block, China","authors":"Hao Xu ,&nbsp;Jie Shen ,&nbsp;Feng Yang ,&nbsp;Qinhong Hu ,&nbsp;Yu Yu ,&nbsp;Liang Xiong ,&nbsp;Tao Zhang ,&nbsp;Hucheng Deng ,&nbsp;Jianhua He","doi":"10.1016/j.marpetgeo.2025.107520","DOIUrl":"10.1016/j.marpetgeo.2025.107520","url":null,"abstract":"<div><div>Sulfur is a critical participant in biogeochemical cycles and in the deposition and preservation of organic carbon, and sulfur compounds and isotope ratios can indicate paleoenvironments. In this study, the major elements, trace and rare earth elements, pyrite morphology, sulfur isotope ratios and detrital zircon U-Pb age dating of shales was performed on shale samples from the Lower Cambrian Qiongzhusi Formation in the Yangtze Block to determine the Early Cambrian marine depositional conditions, the provenance of the shale, and the mechanisms of organic matter (OM) enrichment. The results show that: 1) The source rocks in the sedimentary system were deposited in a continental island arc environment, and originated mainly from the felsic magmatic rocks (such as monzonitic granite) and from tuffaceous rocks in the ancient Kangdian emergent block. 2) Due to the moderate degree of chemical weathering and a generally semi-arid to semi-humid climate, the input of Terrestrial clastics was stable, and the OM dilution effect by Terrestrial clastics was weak; 3) The input of nutrients and the widespread occurrence of hydrothermal activities led to the eutrophication of surface seawater, resulting in high degree of primary productivity; 4) In the restricted sedimentary system, the anoxic-sulfidic bottom water enhanced the enrichment of OM in the Ziyang area, while the bottom water environment was dysoxic with bioturbated sediments and limited preservation of OM in Jingyan area. The lateral heterogeneity of the total organic carbon content in the shale of this formation was greatly affected by changes in OM preservation conditions. These results provide an important basis for a reconstruction of the sedimentary tectonic environment of the Early Cambrian Yangtze Block for a potential shale gas development.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107520"},"PeriodicalIF":3.7,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144489593","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":"Late Permian - Early Triassic transition in the carbonate-evaporite strata of the eastern part of the Qatar-Fars Arch, Persian Gulf basin","authors":"F. Rezvannia ,&nbsp;H. Mosaddegh ,&nbsp;B. Biranvand ,&nbsp;G.P. Nestell ,&nbsp;V. Tavakoli","doi":"10.1016/j.marpetgeo.2025.107524","DOIUrl":"10.1016/j.marpetgeo.2025.107524","url":null,"abstract":"<div><div>The carbonate – evaporite succession of the Permian upper part of the Dalan formation and the Lower Triassic Kangan formation was studied in four wells (A, C, E, and F) from four different fields situated east of the Qatar-Fars Arc in the central part of the Persian Gulf basin, offshore Iran. Foraminiferal species distribution enabled the establishment of the <em>Paraglobivalvulina-Paradagmarita</em> Assemblage zone assigned to the early Wuchiapingian-Changhsingian age. This biozone is divided into two subzones, the Wuchiapingian <em>Globivalvulina vonderschimitti –Paraglobivalvulina</em> aff. <em>mira</em> Assemblage subzone and the Changhsingian <em>Paradagmarita monodi-P. flabelliformis-Paynita permotaurica</em> Assemblage subzone in the upper member of the Dalan formation. The <em>Microconchus-Claraia-Ammodiscus</em> Assemblage zone was also established in the Kangan formation, indicative of an Early Triassic Induan age. The abundance of <em>Paradagmarita monodi, P. flabelliformis</em> in the upper member of the Dalan plays a significant role in paleobiogeographic sub-province correlation within the Neotethys realm. The final occurrence of foraminiferal genera from the Permian-Triassic boundary across all wells reveals a consistent stepwise extinction pattern between 10 and 5 m below the boundary. Furthermore, the presence of a thin thrombolite unit and small framboidal pyrite particles (5–10 μm in diameter) immediately above the Permian-Triassic Boundary (PTB) in wells A, C, F indicates the dominance of dysoxic conditions, which are consistent with a decrease in δ¹³C and δ¹⁸O values, coinciding with a rapid rise in water levels shortly after the extinction event.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107524"},"PeriodicalIF":3.7,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523393","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":"Sedimentology, stratigraphy and reservoir architecture of the Lower Triassic Main Buntsandstein in the Roer Valley Graben, the Netherlands","authors":"E. Cecchetti ,&nbsp;A.W. Martinius ,&nbsp;M. Felder ,&nbsp;M.E. Donselaar ,&nbsp;H.A. Abels","doi":"10.1016/j.marpetgeo.2025.107519","DOIUrl":"10.1016/j.marpetgeo.2025.107519","url":null,"abstract":"<div><div>The Main Buntsandstein Subgroup in the Roer Valley Graben in the southern Dutch subsurface is a sand-prone sedimentary interval deposited in a fluvial-aeolian environment, and is currently investigated for its suitability as target for low-entalpy geothermal exploration. The current depositional models in the Roer Valley Graben do not fully address the facies heterogeneities within and between Buntsandstein sedimentary units and their impact on the prediction of reservoir architecture. A detailed analysis of the Main Buntsandstein sedimentary facies heterogeneities to de-risk future sustainable energy operations is therefore crucial. In the present study, the sedimentology and lithostratigraphy of the Buntsandstein are assessed in a multidisciplinary analysis by use of a subsurface dataset composed of well cores, gamma-ray logs, and thin section data.</div><div>The deposition of the Main Buntsandstein sediments in the Roer Valley Graben is dominated by different fluvial processes, with minor aeolian reworking. River planform style evolved through geological time from highly mobile and ephemeral to more perennial in nature. These changes in river style seem to be dictated by a decrease in climatic aridity along with a decrease in tectonic activity.</div><div>The depositional processes resulted in the development of six lithofacies associations, developing three different types of reservoir architectures with their own set of heterogeneities at different spatial scales. Amalgamated, stacked sandstones have the highest net-to-gross (N/G) with a high degree of lateral and vertical connectivity, and the highest average porosity and permeability. Compensational-stacked sandstone reservoirs have a lower N/G and are the most heterogeneous due to the frequent occurrence of cemented intervals as well as mud drapes in the sandstone bodies. Marginal isolated sandstones show a well preserved relationship between reservoir properties and depositional facies, while more data are needed to resolve the spatial connectivity and lateral continuity of these sandstone bodies.</div><div>The results of this study enhance the understanding of Lower Triassic reservoir architecture and sedimentary heterogeneities in the Roer Valley Graben that can be applied well beyond the area and provide a solid basis for future investigation of the relationship between sedimentary facies, diagenesis, and reservoir quality.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107519"},"PeriodicalIF":3.7,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144595631","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":"Visual representation of machine learning for low-contrast pay logging identification using 2D formation water resistivity variables","authors":"Jingzhe Guo ,&nbsp;Yuxia Wang ,&nbsp;Ya Li ,&nbsp;Pan Zhang ,&nbsp;Lifa Zhou","doi":"10.1016/j.marpetgeo.2025.107518","DOIUrl":"10.1016/j.marpetgeo.2025.107518","url":null,"abstract":"<div><div>Owing to their similar resistivity to water layers, low-contrast pay (LCP) zones may be misinterpreted. While machine learning (ML) methods offer advantages in identifying LCP zones over conventional approaches, their interpretability remains a challenge. This study employs novel approaches to construct sensitive parameters and develop visual representation models, aiming to achieve accurate identification and enhanced model interpretability of Jurassic LCPs in the southwestern Ordos Basin. The key points can be summarized as follows: 1) True and apparent formation water resistivities (FWRs) were calculated from conventional parameters. Based on FWR spectra, the innovative 2D FWR variables were constructed, thereby enhancing distinctions among production-layer types. 2) Nine models were trained using three base learners—support vector machine (SVM), decision tree (DT), and artificial neural network (ANN)—with three sets of input features: conventional parameters, true and apparent FWRs, and 2D FWR variables. The ANN model performed best with an F₁-score of 95.55 % on the testing set when using 2D FWR variables. 3) Cross-plots of 2D FWR variables visually represent model performance. The ANN model's superior performance is attributed to its hidden layer neurons generating four demarcation lines that finely divide the cross-plot into nine zones for classification. In contrast, the SVM model divides the cross-plot into three zones using two demarcation lines, and the DT model's stepped demarcation lines lead to overfitting. The novelties can be summarized as follows: 1) During domain-specific feature transformation, the introduction of 2D FWR variables integrates both morphological information from logging curves and the differences between true and apparent FWRs. 2) Application of 2D FWR variables provides visual insights into ML model principles and performances, thereby facilitating a clearer understanding.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107518"},"PeriodicalIF":3.7,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523392","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":"Seismic evidence for magmatism-driven mud volcanism in the northern continental margin of the South China Sea","authors":"Junhui Yu ,&nbsp;Pin Yan ,&nbsp;Yanlin Wang ,&nbsp;Guangjian Zhong ,&nbsp;Changliang Chen","doi":"10.1016/j.marpetgeo.2025.107523","DOIUrl":"10.1016/j.marpetgeo.2025.107523","url":null,"abstract":"<div><div>The Chaoshan Depression in the northern South China Sea (SCS) margin is abundant with submarine mud volcanoes, and hosts two primary sets of hydrocarbon source rocks within its thick Mesozoic strata. However, the driving mechanism for submarine mud volcanism there remains enigmatic. Here multichannel seismic and ocean bottom seismometer data of line CS-L1 across several mud volcanoes in the Chaoshan Depression are processed and analyzed. Beneath the mud volcanoes, several vertical fuzzy reflection zones are imaged within the Mesozoic strata. They feature distinctly lower velocities than their host strata, and are interpreted as mud diapirs formed by vigorous fluid infilling. High-velocity bodies (HVBs) with Vp &gt; 7.0 km/s are widely imaged below the lower crust and interpreted as post-drift magma underplating bodies. Beneath the mud volcanoes, a thicker HVB extending upward to the depth of ∼15 km is observed, implying locally stronger magma underplating. Moreover, the overlying crust of this thicker HVB also features higher velocities than the surrounding crust. This crustal high-velocity zone extends upward to the shallow depth of ∼9 km, probably representing local magma intrusions sourced from the underlying magma underplating body. This strong association between the submarine mud volcanism and the stronger deep magma underplating and intrusion indicates that the mud volcanism in the Chaoshan Depression of the northern SCS margin was probably magmatism-driven. The deep magma underplating and intrusion firstly caused the surface uplift and the formation of high-angle normal faults. Subsequently, the heat from these intruded magmas promoted hydrocarbon gas generation of the Mesozoic source rocks and increased the pore-fluid pressure, generating mud diapirs within the Mesozoic strata with abundant fluid charging. The submarine mud volcanoes were finally formed with abundant fluids migrating from these mud diapirs to the seafloor along the high-angle faults.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107523"},"PeriodicalIF":3.7,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144336018","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":"Different AOM processes driving the formation of carbonate crusts and nodules in the Okinawa Trough","authors":"Yucheng Zhou ,&nbsp;Hong Cao ,&nbsp;Zhilei Sun ,&nbsp;Wei Geng ,&nbsp;Chenhui Liu ,&nbsp;Xilin Zhang ,&nbsp;Cuiling Xu ,&nbsp;Taiheng Lv ,&nbsp;Shixing Li ,&nbsp;Ye Chen ,&nbsp;Xuejun Jiang ,&nbsp;Dong Zhang ,&nbsp;Yunbao Sun ,&nbsp;Bin Zhai","doi":"10.1016/j.marpetgeo.2025.107510","DOIUrl":"10.1016/j.marpetgeo.2025.107510","url":null,"abstract":"<div><div>Anaerobic oxidation of methane (AOM) serves as a critical process that consumes methane formed in marine sediments and induces the precipitation of cold seep carbonates. However, the factors influencing sulfate-driven AOM (SD-AOM) and iron-driven AOM (Fe-AOM) during the formation of different types of carbonates remain unclear. In this study, mineralogical and geochemical studies were conducted on cold seep carbonate crusts and nodules in the northern Okinawa Trough (OT). Carbonate crusts exhibit rough surfaces with loose textures, while carbonate nodules are characterized by dense and homogeneous textures. The carbonate minerals in the crust samples are predominantly aragonite, whereas the primary carbonate minerals in the nodule samples are calcite and dolomite, as well as calcite and aragonite. The negative δ¹³C values of all samples indicate that the carbon is mainly sourced from biogenic methane. The δ¹⁸O enrichment suggests that the fluid involved in authigenic carbonate formation could be derived from the dissociation of natural gas hydrates. Mineralogical and rare earth element (REE) features reveal that carbonate crusts formed close to the seafloor under high methane fluxes, whereas carbonate nodules developed at greater depths under lower methane fluxes. The predominance of aragonite and low δ¹⁸O_CAS/δ³⁴S_CAS slope (carbonate-associated sulfate, CAS) indicate that SD-AOM drove the precipitation of carbonate crusts. In contrast, the presence of dolomite and siderite, iron-rich microbial structures, and elevated levels of carbonate-associated Fe collectively support the contribution of Fe-AOM during the formation of carbonate nodules. Our study highlights that the distinct formation conditions of carbonate crusts and nodules govern their differential AOM processes.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107510"},"PeriodicalIF":3.7,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321810","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":"Effect of deep-sourced CO2 release on marine silicate weathering as a carbon sink","authors":"Jiyoung Choi ,&nbsp;Ji-Hoon Kim ,&nbsp;Bo-Yeon Yi ,&nbsp;Kyoung-Jin Kim ,&nbsp;Ji-Hyun Kim ,&nbsp;Yuri Kim","doi":"10.1016/j.marpetgeo.2025.107516","DOIUrl":"10.1016/j.marpetgeo.2025.107516","url":null,"abstract":"<div><div>Natural carbon dioxide (CO₂) is produced through various geological and biological processes, including volcanic activity, tectonic movements, and microbial actions in marine sediments. Geochemical analyses of the pore water and gas samples obtained from four sites on the Korea Plateau in the East Sea combined with one-dimensional (1D) modeling was conducted to investigate the origins and behavior of CO₂ in the liquid and gas phases. The sites were classified into two groups based on CO₂ concentration and stable C isotopic composition. The first group, comprising sites 22GH-P02 and 22GH-P09, primarily exhibited biogenic CO₂ from microbial degradation of organic matter. 1D reactive transport (diffusion) modeling indicated that sulfate reduction dominated geochemical processes affecting the vertical distribution of aqueous and gaseous species in the shallow sediments of site 22GH-P02. The modeled biogenic CO₂ concentration in pore water reached up to 38,500 ppmv at a depth of 9.5 m below the seafloor (mbsf). The accumulated biogenic CO₂ contributed to authigenic carbonate precipitation based on the variation of Ca²⁺ and Mg²⁺ profiles and saturation state for carbonates with depth. In contrast, the second group, including sites 22GH-P04 and 22GH-P06, exhibited significantly higher CO₂ concentrations (up to 152,517 and 232,307 ppmv, respectively) with isotopic signatures indicative of a non-biogenic origin. These elevated levels suggest an external CO₂ flux likely originating from thermogenic sources associated with volcanic sills and lava flows, alongside basement faults impacting these sites. This interpretation is further supported by the chemical and isotopic signatures of CO₂ and diverging trends in Ca²⁺ and Mg²⁺ profiles, suggesting that processes other than authigenic carbonate precipitation dominate in Group II. Collectively, this study demonstrates the complex interactions between biogenic and non-biogenic CO₂ sources, highlighting the importance of these dynamics in marine carbon cycling and climate change predictions.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107516"},"PeriodicalIF":3.7,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365771","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":"Paleoenvironment and organic matter enrichment in the Kaijiang–Liangping Trough across the Emeishan Large Igneous Province (ELIP)","authors":"Mengxiang Yu ,&nbsp;Jianhua Zhao ,&nbsp;Keyu Liu ,&nbsp;Qinhong Hu ,&nbsp;Wei Wu ,&nbsp;Quanyou Liu ,&nbsp;Chao Luo ,&nbsp;Yang Chen ,&nbsp;Hongyu Ma ,&nbsp;Zhijun Jin","doi":"10.1016/j.marpetgeo.2025.107517","DOIUrl":"10.1016/j.marpetgeo.2025.107517","url":null,"abstract":"<div><div>The Emeishan Large Igneous Province (ELIP) substantially influenced Permian environmental conditions. This study focused on Middle–Late Permian strata in the Kaijiang and Liangping regions, located ∼800 km northeast of the ELIP center, integrating petrology and geochemistry to investigate the influence of the ELIP on the sedimentary environment and organic matter enrichment. Results indicate that the stratigraphic records preserve eruptive products from different developmental stages of the ELIP. The Kaijiang–Liangping Trough underwent initial uplift followed by subsidence from the late Capitanian to the Wuchiapingian, with organic enrichment patterns differing between northern and southern sections owing to tectonic and volcanic activity. In the north, organic matter is enriched in the siliceous mudstones of the Gufeng Member in the late Capitanian and the upper Wujiaping Formation of the Wuchiapingian age, whereas the south additionally contains coastal swamp facies shales at the base of the Wujiaping Formation. Organic matter enrichment was controlled by high productivity and anoxic conditions during the late Capitanian, whereas elevated sedimentation rates and enhanced terrigenous input attributable to volcanic activity became dominant factors in the early Wuchiapingian. Late Wuchiapingian Emeishan felsic volcanic eruptions might have triggered climatic cooling, promoting upwelling restoration and biotic recovery, with anoxic–euxinic conditions and high productivity jointly governing organic matter enrichment. The negative δ¹³C_org excursion during this period might reflect reduced terrestrial organic matter input caused by sea level rise. This study revealed the spatiotemporal coupling of volcanic and sedimentary processes, offering new insights into hydrocarbon source rock formation in large igneous provinces.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107517"},"PeriodicalIF":3.7,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321809","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":"Mercury in source rocks on the Norwegian Continental Shelf; link to maturity, depositional environment and age","authors":"Sverre E. Ohm ,&nbsp;Guro Skarstein ,&nbsp;Tomas Naeraa ,&nbsp;Fridtjof Riis ,&nbsp;Alejandro Escalona","doi":"10.1016/j.marpetgeo.2025.107511","DOIUrl":"10.1016/j.marpetgeo.2025.107511","url":null,"abstract":"<div><div>The source of mercury (Hg) in petroleum is debated in the literature and could stem from; Hg rich black shales producing petroleum, coals, proximity to deep faults acting as migration routes from deep Hg sources, and proximity to large igneous provinces. In an attempt to cast light on the source of Hg in oils on the Norwegian Shelf 268 mainly organic rich core samples from wells in the North Sea, Norwegian and Barents Sea were analysed for Hg and other heavy metals. In addition 5 core samples from Devonian and Permian reservoir sands and 6 oils from the Embla field were analysed. Our study shows that sediments with elevated Hg concentrations are associated with anoxic depositional environments. The study also show that Hg is mobilized in the source rock at the same temperature interval that generates oil and that the concentration of Hg in the source rock decreases with expulsion of oil. It is suggested that Hg in oil may carry information about the origin of the oil; source rock type and age.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"181 ","pages":"Article 107511"},"PeriodicalIF":3.7,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331071","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}