Marine and Petroleum Geology最新文献

{"title":"Response of source-to-sink patterns during the Mesozoic to tectonic setting in southwestern Tarim Basin: Insights from detrital zircon geochronology and morphology","authors":"Junjian Li ,&nbsp;Liqiang Zhang ,&nbsp;Zuotao Wang ,&nbsp;Yiming Yan ,&nbsp;Cai Chen","doi":"10.1016/j.marpetgeo.2024.107272","DOIUrl":"10.1016/j.marpetgeo.2024.107272","url":null,"abstract":"<div><div>Multiple Mesozoic tectonic movements in the southwestern Tarim Basin led to the change of accommodation space caused by tectonic setting switch, which resulted the process from source to sink being dominated by drainage systems. The source-to-sink pattern with structural features has complicated the distribution of the Mesozoic strata. Since all information is recorded in the associated basin infill, we conducted research on new samples from the Jurassic, Cretaceous, Permian that can provide limitations for the missing Triassic stratum. By analyzing the difference between the depositional age and the crystallization age of zircon grains, we confirmed the Jurassic extensional tectonic setting and the collisional tectonic setting of the Triassic and Cretaceous. By comparing the new detrital zircon geochronological data with the published data, a morphological classification of zircons applicable to complex transport processes was proposed, and the characteristics of provenance indicated by this classification were combined with new sedimentary and seismic stratigraphic evidence to establish two source-to-sink patterns, namely dominated by drainage basin under the Jurassic extensional setting and dominated by drainage channels under the Cretaceous collision setting. Under the Jurassic extensional setting, the debris mainly originated from the Tiekelike Uplift, and the subsidence of the hanging wall resulted in an increase in the accommodation space. The sedimentary system was small, and the distribution direction of isolated sedimentary centers in the sedimentary basin is parallel to the fault, which indicated that drainage basin which perpendicular to the direction of the provenance dominating, reducing the catchment area. Under the Cretaceous collision setting, the transportation of debris from the West Kunlun Orogenic Belt and the Tiekelike Uplift to the basin means that the catchment area increases and the role of drainage basin weakens. The overlapping sedimentary systems and changes in sedimentary facies indicate an increase in number and scale of drainage channels.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107272"},"PeriodicalIF":3.7,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147822","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":"Comprehensive sedimentary studies of mid-late Quaternary strata in the outer shelf of the East China Sea: Facies architecture, chronology, sediment sources, and depositional model","authors":"Taoyu Xu ,&nbsp;Jianxing Liu ,&nbsp;Xiaohui Liu ,&nbsp;Shengfa Liu ,&nbsp;Xisheng Fang ,&nbsp;Zhifang Xiong ,&nbsp;Yanguang Liu ,&nbsp;Xuefa Shi","doi":"10.1016/j.marpetgeo.2024.107274","DOIUrl":"10.1016/j.marpetgeo.2024.107274","url":null,"abstract":"<div><div>The vast East China Sea (ECS) shelf provides a valuable opportunity for validating and refining stratigraphic and sedimentological principles. This research aims to investigate fundamental inquiries regarding facies architecture, chronology, sediment sources, and evolutionary processes of the shallow Quaternary strata of the outer ECS shelf using two deep boreholes, DH02 and DH03, in combination with a comprehensive collection of high-quality boreholes. By integrating sedimentological analyses and identification of benthic foraminifera assemblages, the interpretation of sedimentary facies from various boreholes were systematically reassessed. The facies were classified into four depositional systems: continental system (consisting of river and tidal river facies), estuary system (comprising tidal channel, intertidal, and subtidal flat facies), offshore system (distinguished by tidal ridge facies), and delta-inner shelf system (encompassing prodelta and inner shelf facies). Based on the revision of sedimentary facies, a latitudinal cross-section reveals three sedimentary cycles of the four depositional systems formed the approximately 100 m thick shallow strata. According to the borehole ages (radiocarbon and Optical Stimulation Luminescence), these three sedimentary cycles correspond to glacial eustacy since marine isotope stage 8. The clay mineral composition of borehole DH02 indicates that the Changjiang River likely played a significant role in supplying sediment to the ECS shelf during the mid to late Quaternary period. A spatiotemporal analysis of facies architecture reveals the existence of multiple depocenters, which were presumably influenced by the branching channels and/or channel diversions of the paleo-Changjiang River during this timeframe. A comparison of facies architectures with those of other global shelves indicates that similar sedimentary evolutionary processes are influenced by glacio-eustatism. The integration of findings related to facies architecture, sediment sources, and depocenters contributes to the development of a conceptual depositional model in response to glacio-eustatism.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107274"},"PeriodicalIF":3.7,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147824","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":"Decarbonation generates considerable CO2 in sedimentary basin environments: Implications for the formation of secondary pores","authors":"Lei Song ,&nbsp;Xiaolin Wang ,&nbsp;Wenxuan Hu ,&nbsp;Yuanxian Yang","doi":"10.1016/j.marpetgeo.2024.107273","DOIUrl":"10.1016/j.marpetgeo.2024.107273","url":null,"abstract":"<div><div>Carbon dioxide (CO₂) is a crucial acidic component in sedimentary basins, significantly influencing the formation and evolution of dissolution-type reservoirs. While carbonate decarbonation is a primary source of CO₂, its occurrence under basin conditions remains debated. To address this, we conducted high-temperature, high-pressure <em>in situ</em> and <em>ex situ</em> experiments on the CaCO₃-SiO₂-H₂O, CaMg(CO₃)₂-SiO₂-H₂O, and CaCO₃-SiO₂-H₂O-MgCl₂ systems to investigate decarbonation conditions and mechanisms. The results indicate that temperature is the dominant controlling factor: calcite decarbonation occurs above 275 °C, while magnesium-rich diagenetic systems react at temperatures as low as 100 °C. Pressure inhibits decarbonation, and system openness determines the solid-phases products. In nearly closed systems, kerolite forms and dehydrates into talc, while calcite undergoes dolomitization in the presence of Mg-rich fluids. In open systems, talc dominates, with less dolomitization, and the release of CO₂ promotes decarbonation. Based on these results and previous case studies of silica- and magnesium-rich hydrothermal fluids interacting with carbonate strata, we propose that carbonate decarbonation is a significant source of CO₂ in sedimentary basins, contributing to the development of dissolution-type reservoirs. Further research should explore the implications of these mechanisms for hydrocarbon reservoir formation.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107273"},"PeriodicalIF":3.7,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147823","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":"Passive seismic measurements to characterize gas reservoirs in a mud volcano field in Northern Italy","authors":"Albachiara Brindisi ,&nbsp;Enrico Paolucci ,&nbsp;Nicolò Carfagna ,&nbsp;Dario Albarello","doi":"10.1016/j.marpetgeo.2024.107275","DOIUrl":"10.1016/j.marpetgeo.2024.107275","url":null,"abstract":"<div><div>The presence of a minimum in the average Horizontal to Vertical Spectral Ratios (HVSR) of ambient vibrations has been suggested to be representative of hydrocarbon reservoirs in active oil and gas fields in the Middle East and Europe. Similar evidence has been also found in correspondence of active mud volcanoes in Italy. To explore the possibility of using ambient vibrations to identify and characterize reservoir corresponding to mud volcanoes vents, a dense network of velocimetric measurements (with average inter-distance of 30 m) has been deployed in the Nirano mud volcanoes area (Northern Italy) by considering single station and array configurations (at 59 and 8 sites respectively). Results obtained confirm that measurements with a clear HVSR minimum only characterize the area of emitting vents. In the assumption that this minimum depends on the characteristics of the reservoir responsible for fluid emissions, the Biot–Gassmann theory for seismic waves velocities of gas hydrate-bearing sediments has been considered to infer reservoir characteristics from <em>V</em>_<em>s</em> and <em>V</em>_<em>p</em> profiles obtained by the inversion of the HVSR curves. The satisfactory fit of model outcomes with observations testifies one more the effectiveness of ambient vibration measurements to characterize mud volcanoes and relevant subsoil configuration.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107275"},"PeriodicalIF":3.7,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Salt expulsion triggered by prograding clinoforms in the SW Valencia Trough (SE Spain)","authors":"Adrià Ramos ,&nbsp;Menno J. de Ruig ,&nbsp;Antonio Pedrera ,&nbsp;Pedro Alfaro ,&nbsp;Iván Martin-Rojas","doi":"10.1016/j.marpetgeo.2024.107268","DOIUrl":"10.1016/j.marpetgeo.2024.107268","url":null,"abstract":"<div><div>The impact of salt mobilisation on prograding clinoforms in salt-bearing basins has been documented by several studies. In this work, we have studied a Plio-Quaternary prograding megasequence lying in the SW Valencia Trough in eastern Iberia, aiming to determine the influence of halokinesis on the geometry, extension and trajectory of the prograding clinoforms. Using an integrated dataset comprising 2D seismic profiles and wellbore data, we constructed three restored cross-sections that depict a progradational megasequence predominantly affected by salt-related structures located on the continental shelf. The sequential restorations of the cross-sections illustrate how the Pliocene-Quaternary depocentre of the prograding shelf wedge was controlled by dip-directed normal faults detaching into Triassic evaporites. The subsequent sedimentary loading produced by the prograding clinoforms was associated with salt withdrawal and the collapse of previously inflated Cretaceous-Miocene salt structures (e.g., passive diapirs). Simultaneously, expulsion of salt triggered the development of diapirs around the depocentres. The clinoform architecture captures lateral changes in accommodation space caused by salt mobilisation during the Pliocene and the Quaternary. These changes, alongside other controlling factors such as relative sea level changes and climate, resulted in different rollover point trajectories of clinoforms. The expulsion of salt has also played an important role in the orientation of the main depocentre, which is NNW-SSE in the southern part and changes to a N-S trend in the north due to the influence of the normal fault system. Temporal differences in accommodation space are therefore be explained by the relationship between the rates of sediment progradation and the salt flow. During the Pliocene, when the rate of sediment progradation was lower than the rate of salt flow, wedge-shaped depocentres developed in the hanging wall of the main normal fault along the margin. This disrupted the architecture of the prograding clinoforms. In contrast, during most of the Quaternary, the rate of sediment progradation exceeded the rate of salt flow. As a result, the salt flow was largely suppressed by a prograding overburden formed by well-preserved clinoforms. The interaction between these processes also affected the evolution of the shelf edge location and geometry.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107268"},"PeriodicalIF":3.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The evolution of sulfur during coalification in marine land interaction environments based on the sequential extraction of different sulfur species","authors":"Shuangxue Du ,&nbsp;En Long ,&nbsp;Yu Qi ,&nbsp;Yiwen Ju ,&nbsp;Pan Wu ,&nbsp;Yong Fu ,&nbsp;Shangyi Gu ,&nbsp;Hao Zhang ,&nbsp;Qingguang Li","doi":"10.1016/j.marpetgeo.2024.107266","DOIUrl":"10.1016/j.marpetgeo.2024.107266","url":null,"abstract":"<div><div>The geochemical study of sulfur in coal can not only reveal the source and occurrence of sulfur in coal and provide information about the depositional environment and coal formation process, but also provide necessary theoretical guidelines for coal desulfurization and acid mine wastewater treatment. This study established an extraction method for different forms of sulfur in coal and systematically analyzed the content, distribution and isotopic composition characteristics of various forms of sulfur in Andi-anticline coal in the Qianbei coal field, Guizhou Province, southwest China. The results showed that the main form of sulfur in coal in the research area is pyrite (S_py, averaging 50.3 ± 22.5%), with humic sulfur (HS, averaging 14.3 ± 10.2%) being relatively secondary. Elemental sulfur (S⁰, averaging 1.3 ± 0.5%) is a key intermediate, while ES (sulfur in water-soluble and exchangeable state, averaging 24.5 ± 11.6%) is the product of the oxidation of S_py and HS in the later stage of coalification. The sulfur isotope composition of the total sulfur in the coals was low (−34.1‰ ∼ +13.9‰, with a mean of −3.6‰). The δ³⁴S values of S_py and HS are notably lower than those of seawater sulfate (+10‰) from the Permian coal-forming period. The abundance of sulfate and the extent of sulfate reduction reactions control the evolution of total sulfur content and sulfur isotope composition in different layers. The sulfur isotope offset values Δ³⁴S_SO4-Spy of all coal samples are between +5‰ and +47‰, indicating that the bacterial sulfate reduction is the main controlling factor affecting the sulfur isotope offset in sulfate and sulfide in the entire coal formation system. The light sulfur isotope composition of S⁰ (−2.0 ± 7.3‰) indicate that some of the S⁰ comes from the thermal evolution of HS. In the future, it is necessary to further investigate the specific conversion mechanism between S⁰, organic sulfur and pyrite in the coal formation processes.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107266"},"PeriodicalIF":3.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148059","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":"Gas migration phenomena and pockmark evolution in a Gulf of Mexico minibasin","authors":"Muhedeen A. Lawal,&nbsp;Ann E. Cook","doi":"10.1016/j.marpetgeo.2024.107270","DOIUrl":"10.1016/j.marpetgeo.2024.107270","url":null,"abstract":"<div><div>Seafloor pockmarks vent potent greenhouse gasses into the ocean, support lush chemosynthetic communities and sequester carbon on the seafloor. However, the processes controlling gas migration in the subsurface, gas escape at the seafloor and pockmark evolution are not well constrained. Here, we investigate the evolution of three large, elongated pockmarks and the subsurface gas migration system driving their evolution, using 3D seismic reflection data from a northern Gulf of Mexico salt-withdrawal minibasin. These pockmarks are unique in that they elongate in opposite directions, deepen away from mounds within them and are located in the center of a salt-withdrawal minibasin, a location where vents are rarely documented. The mounds are characterized by high root mean square amplitude anomalies, which are typical of methane derived authigenic carbonate mounds precipitated via anaerobic oxidation of seeping methane over thousands of years in such setting. The pockmarks are underlain by vertical zones of masked reflections (chimneys or gas migration conduits) occurring across a ∼638 m thick sub-seafloor mass transport complex. Below the chimneys, NW-SE oriented normal faults extend upward, terminating below the mass transport complex. These features are geo-spatially related to deeper multi-layer potential gas reservoir sands observed at 3–5 s TWT of the dataset. We argue that the pockmarks elongated under the combined influence of long-term seepage of methane sourced from deep reservoirs and driven vertically upward along faults and chimneys, and authigenic carbonate precipitation. The carbonates sealed part of the pockmarks, causing a deflection in the foci of methane venting and promoting elongation and deepening away from the intra-pockmark carbonates. These seafloor-subsurface linkages may occur in other marine sedimentary basins around the globe.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107270"},"PeriodicalIF":3.7,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148057","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":"A comprehensive review of the characteristics, formation, evolution, resource potential, and ultradeep exploration fields of oil-cracking gas in the Ediacaran–Cambrian formations of the Sichuan super gas basin","authors":"Zeqing Guo,&nbsp;Wenzhi Zhao,&nbsp;Weihong Liu,&nbsp;Hua Jiang,&nbsp;Zhidong Gu,&nbsp;Zengye Xie","doi":"10.1016/j.marpetgeo.2024.107271","DOIUrl":"10.1016/j.marpetgeo.2024.107271","url":null,"abstract":"<div><div>Since the past decade, a super-large gas field with reserves of ∼2 trillion cubic meters has been discovered in the Ediacaran–Cambrian Formations (referred to as Ediacaran–Cambrian hereafter) of the Sichuan super gas basin. In carbonate rocks of the Ediacaran–Cambrian, the geological conditions and reservoir formation issues of natural gas have drawn extensive attention, leading to numerous research advances. However, key geological aspects—such as the genesis of the Deyang–Anyue aulacogen, origin and source of natural gas, process of oil and gas formation, mechanism of gas-reservoir pressure formation and evolution, main controlling factors of natural gas enrichment, and calculation method of oil-cracking gas resources—remain unclear. This study systematically reviews the advancements in research on the Ediacaran–Cambrian of the Sichuan Basin, including the geochemical characteristics and genesis of natural gas and solid bitumen, geological conditions responsible for natural gas accumulation, cracking and gas generation processes in paleo-oil reservoirs, accumulation models, and controlling factors of natural gas accumulation. Results revealed that the understanding of the genesis of the Deyang–Anyue aulacogen has been unified, and the genesis and sources of natural gas have been clarified based on extensive geochemical data of natural gas. In addition, based on a detailed explanation of the geological conditions responsible for the formation of large gas reservoirs in the Ediacaran–Cambrian, the review elucidates the formation of oil and gas along with the formation and evolution mechanisms of gas-reservoir pressure. Further, it establishes an accumulation model and identifies the main controlling factors of the accumulation. Moreover, a calculation formula for the natural gas dissipation coefficient is established to address the deficiencies in existing methods used for calculating the resource quantity of oil-cracking gas. Using a genetic method and PetroMod three-dimensional basin simulation software, the resource quantity of cracking gas is estimated following the technical route of oil formation from kerogen, formation of paleo-oil reservoirs, and subsequent cracking to generate gas. In addition, the oil generation history of the basin and five tectonic units is studied, yielding the resource quantity of paleo-oil reservoirs. Finally, the directions for ultradeep natural gas exploration was further pointed out further indicate. Hence, this study is critical for the oil and gas geological theory and exploration activities of ultradeep, ancient strata. Moreover, this study offers a reference, which is expected to promote the exploration of Ediacaran–Cambrian natural gas in domestic basins (such as Sichuan, Ordos, and Tarim), and holds substantial scientific and practical importance for pioneering the exploration of natural gas in ancient strata from the Middle–Upper Proterozoic to the Lower Paleozoic eras worldwide.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107271"},"PeriodicalIF":3.7,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143147821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water-saturated CO2 injection in a carbonate rock – Effect of pore heterogeneity","authors":"Hang Yin ,&nbsp;Jiachao Ge ,&nbsp;Patrick Kin Man Tung ,&nbsp;Yamin Wang ,&nbsp;Saira ,&nbsp;Ahmad Khayyat ,&nbsp;Furqan Hussain","doi":"10.1016/j.marpetgeo.2024.107260","DOIUrl":"10.1016/j.marpetgeo.2024.107260","url":null,"abstract":"<div><div>Water-saturated CO₂ (wsCO₂) injection is a novel technology that provides better CO₂ storage compared to pure CO₂ injection, due to the superior sweep efficiency of wsCO₂ injection. Previous wsCO₂ injection studies investigated only into sandstones, which have homogeneous pore size distribution. However, wsCO₂ injection into carbonate rock should also be investigated because its substantial heterogeneity hinders sweep efficiency.</div><div>In this study, we use an Indiana limestone core and classify its pores by diameter: large (&gt;200 μm), medium (21–200 μm), and small (&lt;21 μm). The core is saturated with brine first, then oil -in the form of either pure decane (C₁₀) or crude oil - is injected to reduce water saturation. Subsequently, injections of 16 pore volumes (PVs) of either pure CO₂ or wsCO₂ are performed under near-miscible conditions (70 °C and 12 MPa).</div><div>When C₁₀ is used, wsCO₂ injection and pure CO₂ injection are found to have similar CO₂ stored, oil recovery and pressure difference. But when crude oil is used, wsCO₂ injection yields additional CO₂ stored (3%–8.8%) and oil recovery (5%–14%), and greater pressure difference (19–36 times) than does pure CO₂ injection. This study observes that wsCO₂ injection creates emulsion because water vapor from wsCO₂ might be condensed into the oil phase, which consequently increases both flow resistance and pressure difference. Additionally, pure CO₂ could only enter large and medium pores (&gt;21 μm), whereas wsCO₂ was able to enter pores up to 10 times smaller.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107260"},"PeriodicalIF":3.7,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence and formation mechanism of silicate-interlayered iron minerals in hydrate-bearing sediment","authors":"Yuanyuan Li ,&nbsp;Xindi Lu ,&nbsp;Xin Huang ,&nbsp;Hailong Lu","doi":"10.1016/j.marpetgeo.2024.107265","DOIUrl":"10.1016/j.marpetgeo.2024.107265","url":null,"abstract":"<div><div>In this investigation, the geochemical properties of carbonates and iron sulfides in bulk sediment were systematically investigated to elucidate the original depositional characteristics and post-seepage alterations in hydrate-bearing sediments from the mid-continental slope of the Shenhu area, South China Sea. The paleo-sulfate methane transition zone at site W07B was delineated using proxies for carbonate (elevated dolomite levels and δ¹³C-TIC exhibiting negative bias) alongside indicators for iron sulfide (enhanced pyrite levels and δ³⁴S-pyrite showing positive bias) between 132 and 151mbsf. Beyond the typical marine sediment inclusion such as framboid pyrite and foram-shell-filled pyrite, this research reveals a notable occurrence of interlayered silicate pyrite and interlayered siderite, as revealed by EDS and Raman spectrum, marking the novel documentation of such iron-rich secondary minerals in hydrate-bearing sediments. The formation mechanisms and conditions for these authigenic, iron-rich minerals are explored, with their formation linked to the microbial weathering of iron-rich silicate minerals during methane metabolism by entities like methanogens and sulfate-reducing bacteria. The genesis of these minerals is fundamentally driven by the presence of methane-rich fluids and microbial activities. Additionally, the weathering of silicates results in unique secondary mineral assemblages within various chemical zones, where interlayered pyrite appears in the sulfate reduction zone, and interlayered siderite forms within the Fe-Mn reduction zone and/or methanogenic zone. This study shed light on the complex interactions between microbial activities and sediment geochemistry in hydrate-bearing marine settings.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"173 ","pages":"Article 107265"},"PeriodicalIF":3.7,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148058","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}