Marine and Petroleum Geology最新文献

{"title":"‘’Geological characterization of a potential CO2 storage play in the Gela offshore (southern Sicily) and the role of a gravitational slide’’","authors":"Mariagiada Maiorana ,&nbsp;Attilio Sulli ,&nbsp;Matteo Marelli ,&nbsp;Mauro Agate","doi":"10.1016/j.marpetgeo.2024.107127","DOIUrl":"10.1016/j.marpetgeo.2024.107127","url":null,"abstract":"<div><div>In a context where European policies mandating a 55% reduction in CO2 emissions by 2030, Carbon Capture Storage (CCS) presents a viable solution for achieving substantial emissions cuts. Identifying existing and new potential sites for CCS in offshore southern Sicily is crucial to meeting this goal.</div><div>The Gela offshore region is predominantly characterized by the Gela Thrust System (GTS) and its associated Gela Foredeep (GF), a narrow (less than 20 km) and elongated (approximately 100–120 km) depozone that comprises the thicker Plio-Pleistocene sandy sediments of the offshore Sicilian sector. This area is covered by the Gela Slide, a 1500 km² gravitational slide.</div><div>The potential of Plio-Pleistocene clastic deposits in this regionfor CCS implementation has not been previously explored. In this study, we investigated a potential caprock-reservoir system covering around 840 km² in the Gela offshore area. Our analysis involved interpreting key horizons from a dense grid of 2D seismic reflection profiles, conducting well-to-seismic tie analysis and developing a refined velocity model.</div><div>The study reveals a promising storage play within the foredeep basin-filling deposits. This potential storage play consists of Lower Pleistocene foredeep turbidite sands of Sabbie di Irene Fm. (reservoir) and of the Middle-Upper Pleistocene pelitic deposits of the Argo Fm. (primary seal). Additionally, the basal shear level of the Gela Slide has been investigated as a potential secondary seal. Analyzing its extent, age, and interaction with the GTS offers valuable insights into the relationships between tectonics and sedimentation, which could lead to the identification of suitable sealing layers for CCS purposes.</div><div>This study thus provided new data on the thickness, depth, facies and rock volumes of the main reservoir and seals, highlighting their potential suitability for CCS applications.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107127"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327720","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":"Quantum physisorption behavior of methane in nanoporous shales: Model and new mechanism","authors":"Junqian Li ,&nbsp;Xiaodong Yang ,&nbsp;Min Wang ,&nbsp;Jianhua Zhao","doi":"10.1016/j.marpetgeo.2024.107129","DOIUrl":"10.1016/j.marpetgeo.2024.107129","url":null,"abstract":"<div><div>Methane adsorption in nanoporous shales plays a significant role in the storage and flow of shale gas. Although previously numerous theoretical models have been proposed to describe the gas adsorption behavior, how the potential energy distribution in nanopores impacts gas adsorption remains unclear. The mechanism of methane adsorption in extremely complicated nanopores is still no satisfactory explanation. In this study, a total of 28 shale samples located in the Paleozoic-Mesozoic strata from different sedimentary environments were utilized to investigate the nature and process of quantum physisorption of methane in nanoporous shales. It was suggested that methane confined within nanoscale space shows a quantum effect, and the physisorption behavior of methane may be the result of molecular energy level transition. Further, the quantum physisorption model was developed by considering the quantum potential energy distribution, maximum adsorption amount, gas temperature and gas pressure, which matches the isothermal adsorption data well for a various of shales under widely varied temperature and gas pressure condition. The adsorption amounts of methane with different energy levels can also be obtained by the model. Finally, a new mechanism of the methane quantum physisorption in nanoporous shales was proposed. Uneven spatial distribution of gas molecules and elementary space of gas adsorption are the intrinsic factors of controlling the quantum physisorption behavior. The former is mainly influenced by minimum potential unit (<em>E</em>₀) and gas temperature, while the latter is represented by the parameter of maximum adsorption amount (<em>n</em>_<em>L</em>) which impacted by specific surface area and gas temperature. Gas pressure only affects the molecule concentration with different energy levels, but does not affect the spatial distribution of molecule. <em>E</em>₀ and <em>n</em>_<em>L</em> vary in shales from different sedimentary environments, due to the difference in organic matter properties (TOC content and kerogen type), which indirectly impacts the methane physisorption behavior. These results are helpful to deeply understand the storage of methane in shales and improve the efficient development of shale gas. In addition, this study is expected to open a new research direction about the quantum physisorption of gas in nanoporous media.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107129"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359052","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":"Fault characterization and its significance on hydrocarbon migration and accumulation of western Tazhong Uplift, Tarim Basin: Insight from seismic, geochemistry, fluid inclusion and in situ U-Pb dating","authors":"Feifei Yuan ,&nbsp;Jinqiang Tian ,&nbsp;Fang Hao ,&nbsp;Zhuo Liu ,&nbsp;Ke Zhang ,&nbsp;Xiaoxue Wang","doi":"10.1016/j.marpetgeo.2024.107137","DOIUrl":"10.1016/j.marpetgeo.2024.107137","url":null,"abstract":"<div><div>Understanding the mechanisms of deep hydrocarbon accumulation is of paramount importance in the field of petroleum geology. Studying deep hydrocarbon accumulation mechanisms contributes to the development of effective reservoir management strategies and efficient extraction techniques. In this study, fluid inclusion observation, homogenization temperatures, in situ calcite U-Pb dating, geochemical analyses and seismic data were applied to investigate the hydrocarbon charging history of the western Tazhong Uplift, and the migration pathways were further analyzed to establish the history of oil and gas accumulation in the study area. The results reveal three distinct episodes of oil and gas charging processes in the western Tazhong Uplift. The first episode, determined by in situ calcite U-Pb dating bearing primary oil inclusions, occurred during the late Caledonian to early Hercynian orogeny. This episode is characterized by yellowish fluoresce color oil inclusions. The second episode involved a complex variation of the thermal maturity of oil. Mature oil, with oil inclusions preferentially fluorescing yellow-green color, was charged into the reservoirs near the Tazhong No.1 fault. Subsequently, the high mature oil characterized by blue-fluorescing oil inclusions was charged. At the same time, the mature oil migrated vertically into the reservoir away from the Tazhong No.1 fault along the strike slip faults. The third charging process is dominant by high mature oil in the Southwest of the western Tazhong Uplift, whereas the gas intrusion occurred in the area near the Shuntuoguole Low Uplift. Furthermore, the strike slip faults and reverse faults were distinguished based on the seismic profiles and coherence diagram. The intersections of strike slip faults and Tazhong No.1 fault developing more fractures served as oil and gas charging points. The oil production revealed that the strike slip faults acted as important hydrocarbon migration pathways. This study provides valuable insights into the processes of hydrocarbon accumulation and offers further evidence for deep oil exploration in the region.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107137"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428160","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":"The influence of shallow-water methane emissions on foraminiferal assemblages: The case of Scoglio d’Affrica (Northern Tyrrhenian Sea, Mediterranean Sea)","authors":"Letizia Di Bella ,&nbsp;Martina Pierdomenico ,&nbsp;Aida Maria Conte ,&nbsp;Irene Cornacchia ,&nbsp;Tania Ruspandini ,&nbsp;Daniele Spatola ,&nbsp;Stanley Eugene Beaubien ,&nbsp;Sabina Bigi ,&nbsp;Alessia Conti ,&nbsp;Giovanni Gaglianone ,&nbsp;Michela Ingrassia ,&nbsp;Francesco Latino Chiocci ,&nbsp;Daniele Casalbore","doi":"10.1016/j.marpetgeo.2024.107130","DOIUrl":"10.1016/j.marpetgeo.2024.107130","url":null,"abstract":"<div><div>Microfaunal analyses were conducted near Scoglio d’Affrica in the Tuscan Archipelago (Northern Tyrrhenian Sea), to study the response of benthic foraminifera to methane (CH₄) venting activity that occurs in this shallow water environment. Our data show that sedimentary processes linked to the CH₄ emissions exert a strong influence on foraminiferal assemblages, resulting in a very patchy spatial distribution linked to complex abiotic and biotic interactions. Methane emissions and mud represent the two main stressor factors for the benthic foraminiferal assemblages, although at present it is not possible to determine which impact dominates.</div><div>Five different morphological settings, controlled by venting activity, were defined on and off the mud volcanoes (MVs). Each of these settings has distinct assemblages: 1) areas with strong emission activity at the top of the MVs, locally associated with gryphons and mudflows, where the environmental conditions are clearly prohibitive for foraminiferal life; 2) mud flows along the MV flanks, where overlapping mudflows likely limit foraminiferal colonization; 3) muddy sediments associated with weak emissions where the development of foraminiferal community is favored, although with differences in terms of density, diversity and compositional features linked to the timing of colonization by each species; 4) intermatte zones with scarce or absent emissions, characterized by typical shallow water taxa indicative of well-oxygenated and highly hydrodynamic conditions; and 5) <em>Posidonia oceanica</em> substrates, characterized by higher foraminiferal content on the leaves compared to the rhizomes and surrounding sediments; indeed, sediments and rhizomes were more impacted by emissions, whereas <em>Posidonia</em> leaves offer “refugia” and a more mitigated environment.</div><div>Although it is difficult to define a pattern of biota response and to identify seep-exclusive taxa, foraminifera can represent good environmental proxies for both monitoring the variability of recent venting activity and detecting stressed conditions occurring in the geological record. The seafloor around Scoglio d’Affrica represents a very promising study site for multidisciplinary marine research regarding venting activity, geochemistry of cold seep fluids and their effects on benthic organisms.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107130"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324021","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":"Mio-pliocene evolution of deep-water channels on the northeastern Bengal fan: Records of signals of Himalaya uplift and South Asian Monsoon from source areas","authors":"Kun Qi ,&nbsp;Liangbo Ding ,&nbsp;Chenglin Gong ,&nbsp;Dali Shao ,&nbsp;Hongxia Ma","doi":"10.1016/j.marpetgeo.2024.107133","DOIUrl":"10.1016/j.marpetgeo.2024.107133","url":null,"abstract":"<div><div>Submarine channels, acting as major conduits for delivering terrestrial sediments into the deep sea, are sensitive to source-region uplift and climate variations. Using new 3D seismic data, previously published paleoenvironmental data, and IODP/ODP data, we characterize stratigraphic time changes in deep-water channels on the northeastern Bengal Fan and suggest that their long-term evolution relates to contemporaneous changes of Himalaya uplift and South Asian Monsoon. Our results show that around the boundary between the Miocene and Pliocene Epochs, the sedimentary characteristics of deep-water channels were changing at about the same time as decreased rates of Himalaya uplift and changes in the monsoonal climate. It is strongly suggested that environmental signals could successfully propagate from the Himalaya to the deep sea and play a dominant control on the long-term evolution of deep-water channels. During the late Miocene, orogen-wide and substantial Himalaya uplift and humid monsoonal climates (dominance of summer monsoon) generated a sediment supply with high fluxes, which allowed coarser-grained sediments to reach further into the basin and thus caused the formation of larger-scale, non-leveed erosional channels that have avulsion and confluence phenomena. After the Miocene, local and limited Himalaya uplift and arid monsoonal climates (dominance of winter monsoon) led to a sediment supply with low fluxes, during which only finer-grained sediments reached deep water and gave rise to smaller-scale, leveed aggradational channels that mainly have splay deposits. Between the late-Miocene and post-Miocene periods, detrital zircon U-Pb ages of Bengal Fan samples from IODP cores reflect a sediment provenance change from the mixing of Brahmaputra and Ganges Rivers to the end-member of Brahmaputra River, broadly coeval with the variations of Himalaya uplift and South Asian Monsoon. Moreover, Bengal Fan cores record a Mio-Pliocene decrease in sedimentation rates and maximum grain sizes and an increase in mudstone contents, consistent with the variations of sediment yield in the source catchments. Observations and interpretations from the current study, therefore, contribute to a better understanding of how the long-term evolution of submarine channels respond to tectonic and climatic perturbations in source areas and may help recognizing similar process-response relationships in other areas.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107133"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359050","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":"Chemostratigraphy and mineralogical characterization of Piacenzian sapropels cluster A (2.75–2.57 Ma) in the Gelasian GSSP type-section of Monte San Nicola (Sicily, Italy): Paleoenvironmental and paleogeographic implications","authors":"Stefano Fasone ,&nbsp;Giovanna Scopelliti ,&nbsp;François Baudin ,&nbsp;Antonio Caruso","doi":"10.1016/j.marpetgeo.2024.107131","DOIUrl":"10.1016/j.marpetgeo.2024.107131","url":null,"abstract":"<div><div>Mineralogical, geochemical and stable isotope (δ¹⁸O, δ¹³C) data from Marine Isotope Stages (MIS) G4 to 103 are here presented. The studied interval includes the sapropelic cluster A (A2-A5) from the Gelasian GSSP type-section, outcropping at Monte San Nicola (Sicily, Italy). The studied section exhibits a good response of the δ¹⁸O measured on the bulk carbonate to the Earth's astronomical parameters. The sapropelic red/brown layers (A2- A5) are alternated to grey marls and this cyclicity is clearly evident by the difference in colour, organic matter content, redox-sensitive elements and runoff indicators, tied to the precession/insolation cycles. Further, the obliquity signal is well evident in paleoproductivity indicators and mineralogical composition, driven by glacial-interglacial cycles. The obtained dataset has allowed the reconstruction of the paleoenvironmental conditions during marls/sapropels deposition, which appears to be influenced by the precessional forcing that induced strong changes in the marine water circulation. This scenario is also integrated by an original paleogeographic model including the presence of a high topographic structure in SE Sicily that limited water exchanges between the Ionian and Central Mediterranean Seas during sea level drawdowns, caused by glacial phases, triggered by obliquity minima.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107131"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359049","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":"Causal sources of the significant high-amplitude magnetic anomaly zone in the northern south China Sea continental margin","authors":"Wen-Bin Doo,&nbsp;Yin-Sheng Huang","doi":"10.1016/j.marpetgeo.2024.107128","DOIUrl":"10.1016/j.marpetgeo.2024.107128","url":null,"abstract":"<div><div>The magnetic anomaly map shows an obvious NE-SW trending high-amplitude magnetic anomaly zone (NSCSMA) in the northern South China Sea (SCS) continental margin that extends from southwest Taiwan to the area at approximately 114°E and 20°N. The origin of this high-amplitude magnetic anomaly zone is important for understanding the magmatism, margin rifting, and tectonic evolution of the SCS. To gain insight into this issue, in this study, wavelet spectrum analysis, 2D magnetic modeling, and compact inversion were used to identify the causal source of the NSCSMA. Combining wavelet spectrum analysis with magnetic modeling results, we find that the depths of the major magnetic sources are not consistent along the strike of the NSCSMA (∼15 km in the east and ∼25 km in the west). The compact inversion results along five profiles across the NSCSMA also revealed two kinds of geometries (quasi-dike in the east and dome-like in the west) of the causal sources of the NSCSMA with different depths. Based on our findings and previous paleo-subduction model, we propose that the major source of the NSCSMA is serpentinized upper mantle materials associated with paleo-Pacific plate subduction.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107128"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324019","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":"The paleo-oceanic environment and organic matter enrichment mechanism of the early Cambrian in the southern Lower Yangtze platform, China","authors":"Dongsheng Zhou ,&nbsp;Hezheng Dong ,&nbsp;Xiaowei Huang ,&nbsp;Yufei Liang ,&nbsp;Ziyan Deng ,&nbsp;Lei Huang ,&nbsp;Shu Jiang","doi":"10.1016/j.marpetgeo.2024.107119","DOIUrl":"10.1016/j.marpetgeo.2024.107119","url":null,"abstract":"<div><div>This study focuses on the Lower Yangtze Platform located in southern Anhui Province, focusing on the black shale of the early Cambrian Hetang Formation as the primary research subject. Three field sections representing distinct sedimentary structural units were selected for investigation. Analytical methodologies encompassing organic geochemistry, elemental geochemistry, and scanning electron microscopy were employed to reconstruct paleo-oceanic environmental conditions. These analyses aimed to elucidate the characteristics of marine surface productivity and identify the factors controlling organic matter formation, thereby establishing a model for organic matter accumulation processes. These findings suggest that the Jiangnan paleo-uplift exerted differentiated control over organic matter formation and accumulation. Specifically, the barrier function of the paleo-uplift fostered a relatively enclosed and restricted water environment in certain regions, which proved conducive to the formation, accumulation, and preservation of organic matter. Furthermore, the paleo-upwelling system and hydrothermal groundwater circulation triggered by the activation of the Jiangnan deep fault played crucial roles in controlling the formation and accumulation of organic matter in the early Cambrian. Notably, the research also revealed that intermittent hydrothermal activity had a dual impact on organic matter accumulation within various paleo-oceanic settings. This process potentially facilitated organic matter enrichment and led to the dilution of organic matter concentrations.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107119"},"PeriodicalIF":3.7,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327718","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":"Sedimentation-controlled double BSRs and implications for paleo hydrate dissociation in the Shenhu area, south China sea","authors":"Wei Deng ,&nbsp;Pin Yan ,&nbsp;Zenggui Kuang ,&nbsp;Jinqiang Liang ,&nbsp;Miaomiao Meng ,&nbsp;Lei Lu","doi":"10.1016/j.marpetgeo.2024.107132","DOIUrl":"10.1016/j.marpetgeo.2024.107132","url":null,"abstract":"<div><div>Double/multiple bottom-simulating reflectors (BSRs) have been discovered worldwide, but their preservation and formation mechanism remain unclear because most studies are based on seismic data, lacking direct evidence like well logging data. This study introduces a novel well log-based interpretation of double BSR, suggesting that the secondary BSR (BSR2) is the interface between little residual gas and the overlying water-saturated sediment, and the free gas is trapped by capillary seals. The BSR2's amplitude is influenced by the nearby porosity, with lower porosity resulting in stronger reflections. Seismic attributes reveal a dynamic process of hydrate cycle that hydrate dissociation occurs above BSR2, followed by gas migrate to form a new BSR1. The upshift of BSR2 is mainly controlled by sedimentation rate, which varies across different regions, leading to larger upshifts in areas with higher sedimentation rates. Moreover, BSR2's upshift is negatively related to the reflection magnitude of BSR2, because rapidly depositing sediments with higher porosity and lower percolation threshold allow lesser gas sealed beneath the BSR2. Our findings suggest that double BSRs are predominantly formed in muddy sediments under rapid geological events like rapid sedimentation. However, each BSR can be preserved as well as observed to indicate that the BSR has existed for an extended period of time during which the geologic environment has been relatively stable, e.g., low sedimentation rates. This detailed sedimentation-controlled BSR adjustment provides new insights for the interpretation of double BSR and the paleo hydrate dissociation.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107132"},"PeriodicalIF":3.7,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318784","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":"High-resolution chemofacies and pore system characterization of the Pennsylvanian Cline Shale, Midland Basin, Texas","authors":"Ximeng Wang,&nbsp;Ethan L. Grossman,&nbsp;Mauro R. Becker","doi":"10.1016/j.marpetgeo.2024.107120","DOIUrl":"10.1016/j.marpetgeo.2024.107120","url":null,"abstract":"<div><div>The connections between the depositional environment, sediment chemistry, and pore structure of deep-water mudstones are still not completely understood. This study: 1) investigates the sediment chemistry and the depositional conditions of the Pennsylvanian Cline Shale chemofacies in the center of the Midland Basin, 2) characterizes the conditions favorable to organic matter accumulation of each mudstone chemofacies, and 3) examines the connection between the pore structure and the mudstones’ paleo-environmental and paleo-geochemical context and processes. This study uses X-ray fluorescence (XRF) and statistical methods (Isolation Forest, Principal Component Analysis, and K-means) to identify four chemofacies of 127 m of Cline Shale core from the Matthew 'D' 0906 well located in the Midland Basin depocenter in Glasscock County, Texas. In addition, petrographic and scanning electron microscopy and measurements by dual-energy computed tomography, X-ray diffraction, Rock-Eval pyrolysis, N₂ isothermal adsorption tests, and mudrock reservoir properties were conducted on thin-sections, core slabs, and samples to understand the bulk geochemistry and petrophysical properties of the mudstones. Four chemofacies are identified: (1) Siliceous Mudstone with high Zr and low Ca and P, (2) Calcareous-argillaceous Mudstone I with high Ca and Zr, and low P, (3) Argillaceous Mudstone with high P and low Ca and Zr, and (4) Calcareous-argillaceous Mudstone II with high Ca and P, and low Zr. Based on elemental distribution, the first two and last two chemofacies are interpreted as low sea-level deposits and high sea-level deposits, respectively. Water stratification and P regeneration accounted for the highest total organic carbon (TOC) content, which resulted in the high porosity and pore volume of the low sea-level Siliceous Mudstone chemofacies, especially visible in the 8 nm–186 nm organic matter pores. Carbonate input hinders the development of the inorganic pore system, especially for organic lean Calcareous-argillaceous Mudstones. Nine sea-level cycles were observed in the cores and correlated to nine US mid-continent cycles attributed to the 405-kyr Milankovitch parameter (long orbital eccentricity) during the late Pennsylvanian. We hypothesize that late Pennsylvanian climate change, paced by orbital cycles, controlled the distribution and stacking pattern of mudstone chemofacies, which also controlled source rock quality and consequent pore system development.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107120"},"PeriodicalIF":3.7,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327719","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}