International Journal of Coal Geology最新文献

{"title":"Editorial of the special issue: 75th ICCP meeting: Organic petrology research and applications for the 21st Century","authors":"Angeles G. Borrego","doi":"10.1016/j.coal.2025.104842","DOIUrl":"10.1016/j.coal.2025.104842","url":null,"abstract":"","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"308 ","pages":"Article 104842"},"PeriodicalIF":5.7,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144621942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enrichment of Ni-Zn-Cd-Mo-V in the Şırnak asphaltites, Türkiye: The effects of organic matter, sedimentary processes, and hydrothermal fluids on element concentrations and occurrences","authors":"Emine Cicioglu Sutcu","doi":"10.1016/j.coal.2025.104846","DOIUrl":"10.1016/j.coal.2025.104846","url":null,"abstract":"<div><div>There are numerous asphaltite veins in southeastern Anatolia, Turkey. The Avgamasya, Anılmış, Harbul, Silip, and Üçkardeşler veins, which are the focus of this study, are enriched in elements such as As, Cd, Mo, Ni, Sb (except in Harbul), U, V, Zn, and Hg. Commonly detected minerals across all samples include dolomite, calcite, apatite, pyrite, sphalerite, alkali feldspar, quartz, illite, and iron oxides. Additionally, smectite, barite, celestine, ilmenite, galena, hematite, rutile, and strontianite were also observed. The mineral matter present can be both syngenetic and epigenetic. The microcrystalline minerals present within solid bitumen may have precipitated from supersaturated fluids during the maturation of hydrocarbons. In contrast, epigenetic minerals may have originated from hydrothermal fluids after the solid bitumen was formed or may have been incorporated from the surrounding host rocks during the hydrocarbon migration process. Organisms in the shelf environment likely played a crucial role in the enrichment of these elements. Sedimentary and diagenetic processes, sediment pore waters, and hydrothermal fluids may have significantly contributed to the formation of minerals that host these enriched elements. Solid bitumen, iron oxides, pyrite, and sphalerite can serve as major carriers of these enriched elements. Meanwhile, lithophile elements such as Sr, Ba, and Na are typically found in minerals like barite, strontianite, celestine, calcite, apatite, and fossil shells.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"308 ","pages":"Article 104846"},"PeriodicalIF":5.6,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maceral point counting for dispersed organic matter (DOM)","authors":"Zhiheng Zhou,&nbsp;Hamed Sanei","doi":"10.1016/j.coal.2025.104818","DOIUrl":"10.1016/j.coal.2025.104818","url":null,"abstract":"<div><div>Point counting is a widely used quantitative technique in microscopic analysis for estimating the volume percentage of target constituents within a sample. Its application in coal petrography has been standardized through international guidelines such as ISO 7404 and ASTM D2797/D2799, which were primarily developed for the analysis of carbonaceous materials such as coal and peat. These standards have governed sample preparation, maceral identification, and point counting procedures since the 1980s. However, modern applications of coal petrography point counting to dispersed organic matter (DOM), particularly in low-TOC samples, have revealed methodological incompatibilities. As a result, significant procedural modifications have been implemented across laboratories, but no universally adopted approach has been established.</div><div>To address these challenges, this study proposes and evaluates a point counting method for dispersed organic matter (DOM) using a 21-crosshair grid reticle. The method embeds 21 crosshairs within a 60-μm-diameter region (under 500× magnification) in the microscope system and requires counting at least 300 suitable microscopic fields where all crosshairs fall on sample particles. The use of 21-crosshair grid increases the probability of intersecting DOM in sample particles within pellets. This results in a 68 % reduction in analysis time (from 2.5 h to 1.0 h per sample) compared to when traditional coal petrography point counting is applied to DOM. Furthermore, the use of a denser grid in the 21-crosshair DOM point counting method improves measurement accuracy by more effectively capturing the areas of constituents within sample particles. By requiring the counting of at least 300 suitable microscopic fields, it generates a robust dataset of over 6300 points, achieving strong correlations (R² &gt; 0.80) between the volume percentage of maceral assemblage and TOC in case studies. The method has been validated in applications such as hydrocarbon potential assessment, solid bitumen characterization, thermal maturity analysis, and depositional environment reconstruction. This paper bridges the gap between traditional standards and modern analytical needs by proposing a standardized, efficient, and reliable method for DOM point counting.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"307 ","pages":"Article 104818"},"PeriodicalIF":5.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the ash samples before and after thermal processing aiming phosphorus extraction and residues valorization","authors":"Georgeta Predeanu ,&nbsp;Bruno Valentim ,&nbsp;Luminita Georgeta Popescu ,&nbsp;Alexandru Traian Abagiu ,&nbsp;Lucica Anghelescu ,&nbsp;Mihaela Niculina Bălănescu ,&nbsp;Barbara Białecka ,&nbsp;Elza Bontempi ,&nbsp;Magdalena Cempa ,&nbsp;Marius Florin Drăgoescu ,&nbsp;Alexandra Guedes ,&nbsp;Özben Kutlu ,&nbsp;Mattia Massa ,&nbsp;Elsayed Mousa ,&nbsp;Adrian Ionut Nicoară ,&nbsp;Hayati Olgun ,&nbsp;Valerica Slăvescu ,&nbsp;Bogdan Stefan Vasile ,&nbsp;Guozhu Ye","doi":"10.1016/j.coal.2025.104808","DOIUrl":"10.1016/j.coal.2025.104808","url":null,"abstract":"<div><div>This paper presents the prospect of phosphorus (P) - rich poultry litter manure ash (PLA) used to recover P through microwave heating methods, aiming for residual slag recycling in constructions.</div><div>The results show the complex composition of the ashes characterized by X-ray fluorescence (XRF), reflected light optical microscopy, X-ray microanalysis (SEM/EDS) and X-ray diffraction (XRD), which explains the differences between the ash types and the operation temperature in the combustion chamber. At the same time, the results present a novel approach of using microwave heating by reducing energy consumption to extract/enrich P from PLA and forming a by-product/residual slag used as a supplementary cementing material.</div><div>Samples of fly ash (FA) and bottom ash (BA) were collected from two fluidized bed incinerators (Güres and Beypi in Türkiye) operating at 750 °C and 850 °C within the PHIGO project funded by the 3rd ERA-MIN Program of the European Union Commission.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"307 ","pages":"Article 104808"},"PeriodicalIF":5.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial of the special issue: The 2023 joint 74th ICCP and 39th TSOP meeting: Organic petrology in the energy transition era: Challenges ahead","authors":"Stavros Kalaitzidis,&nbsp;Kimon Christanis","doi":"10.1016/j.coal.2025.104811","DOIUrl":"10.1016/j.coal.2025.104811","url":null,"abstract":"","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"307 ","pages":"Article 104811"},"PeriodicalIF":5.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144237512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating coalbed gas productivity response from hydrogeochemical and microbial perspectives: A case study of the Liulin block, eastern Ordos Basin, China","authors":"Yueguo Li ,&nbsp;Haijiao Fu ,&nbsp;Xianbo Su ,&nbsp;Detian Yan ,&nbsp;Gang Wang ,&nbsp;Shuguang Yang ,&nbsp;Xing Chen ,&nbsp;Jianzhang Liu ,&nbsp;Jintao Kong","doi":"10.1016/j.coal.2025.104817","DOIUrl":"10.1016/j.coal.2025.104817","url":null,"abstract":"<div><div>The benefits of coalbed gas (CBG) development are directly affected by the production capacity level. Previous studies of CBG productivity response have mainly focused on the hydrogeochemical characteristics of produced water, and paid less attention to the correlation between microbial communities and productivity. This study focuses on nine CBG wells in the Liulin Block of the eastern Ordos Basin, systematically analyzing the CBG genesis, as well as the relationships between hydrogeochemical parameters, microbial community characteristics and CBG productivity. The results show that the CBG in Liulin Block is a mixture of secondary biogenic gas and thermogenic gas, and the proportion of biogenic methane is 48.0 % to 49.7 %. The total dissolved solids (TDS) content is positively correlated with the average daily production of CBG, and the concentration of HCO₃⁻ is negatively correlated with the average daily gas production. The concentration of elemental Sn in the produced water is significantly correlated with average daily gas production. Positive δ¹³C_DIC values indicate the occurrence of microbial methanogenesis. Analysis of the microbial community shows that the bacterial community exhibits significant functional diversity, with <em>Hydrogenophaga</em> having the highest relative abundance and a positive correlation with average daily production of CBG. The archaeal community is dominated by methanogenic archaea. From the perspective of community diversity, the Operational Taxonomic Units (OTU) number, Chao1 and Ace indexes of the archaeal community show a positive correlation with average daily gas production. This study provides a novel perspective for research on microbial indicators of CBG production.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"307 ","pages":"Article 104817"},"PeriodicalIF":5.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Component identification of solid biomass fuels using reflected light microscopy: Interlaboratory study 2","authors":"Agnieszka Drobniak ,&nbsp;Maria Mastalerz ,&nbsp;Zbigniew Jelonek ,&nbsp;Iwona Jelonek ,&nbsp;Menandro N. Acda ,&nbsp;Tushar Adsul ,&nbsp;Neža Malenšek Andolšek ,&nbsp;Lorenzo Animali ,&nbsp;Omid H. Ardakani ,&nbsp;Telma Ataide ,&nbsp;Demberelsuren Batbold ,&nbsp;Mohd Younus Bhat ,&nbsp;Tara Congo ,&nbsp;Bryon S. Donohoe ,&nbsp;Olugbenga A. Ehinola ,&nbsp;Deolinda Flores ,&nbsp;Carolina Fonseca ,&nbsp;Santanu Ghosh ,&nbsp;Paula Gonçalves ,&nbsp;Paul C. Hackley ,&nbsp;Konrad Ziemianin","doi":"10.1016/j.coal.2025.104814","DOIUrl":"10.1016/j.coal.2025.104814","url":null,"abstract":"<div><div>As nations transition toward sustainable energy systems, biomass has become a vital component of global energy portfolios. Derived from organic materials such as wood, agricultural residues, forestry byproducts, and organic waste, biomass is a renewable energy source with significant environmental and economic benefits. Responsible biomass energy production can improve waste management, reduce emissions of greenhouse gases, and mitigate environmental pollution. However, as the diversity of biomass-derived fuels increases, robust quality assessment methods are essential to ensure their efficiency, safety, and minimal environmental impact.</div><div>Reflected light microscopy (RLM) is one such technique with the potential to complement conventional physico-chemical analyses by enabling a rapid identification of material constituents and impurities. To refine this methodology and evaluate the reproducibility of solid biomass component identification using RLM, an interlaboratory study (ILS) was conducted. The study involved the recognition of 58 components across 45 photomicrographs, with the participation of 65 scientists and students from 25 countries.</div><div>The participants faced high difficulty identifying some of the marked components, and as a result, the percentage of correct answers ranged from 19.0 % to 98.3 %, with an average correct identification rate of 62.7 %. The most challenging aspects of the identification process included distinguishing between woody and non-woody (agro) biomass, accurately identifying petroleum-derived materials, and differentiating agro biomass from inorganic matter.</div><div>The results suggest that while RLM is an important tool for characterizing solid biomass, further development of methodology guidelines and training are necessary to enhance its effectiveness. Future research should prioritize preparing detailed, image-rich, microscopic morphological descriptions of biomass fuel components, which could improve the accuracy and reliability of using RLM in biomass fuel characterization.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"307 ","pages":"Article 104814"},"PeriodicalIF":5.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluvial architectural style and stacking patterns in a high-accommodation coal-bearing succession: the upper Permian Newcastle Coal Measures, eastern Australia","authors":"Christopher R. Fielding ,&nbsp;Stephen McLoughlin ,&nbsp;Chris Mays ,&nbsp;Allen P. Tevyaw ,&nbsp;Tracy D. Frank","doi":"10.1016/j.coal.2025.104829","DOIUrl":"10.1016/j.coal.2025.104829","url":null,"abstract":"<div><div>The upper Permian Newcastle Coal Measures (NCM) host world-class coal resources in coastal New South Wales, Australia. They formed close to the foredeep axis of a developing retroarc foreland basin associated with the Hunter-Bowen contractional event. In addition to the typical coal-bearing lithological suite of mudrocks, heteroliths, sandstones, and coals (with several beds of volcanic ash), the NCM preserve numerous, linear bodies of conglomerate up to 100 m thick and 20 km wide that are anomalous in the context of paralic coal-bearing successions worldwide. Four facies associations are recognized: A) linear bodies of conglomerate, gravelly sandstone and sandstone, interpreted as the deposits of major coastal plain channels, B) interbedded mudrocks and sandstones, interpreted as the product of coastal plain floodplains and floodbasins, C) coals and coaly mudrocks, interpreted as the product of coastal plain mires, and D) massive and bedded tuffs, interpreted as the product of pyroclastic falls and flows from nearby stratovolcanoes. Despite having formed on a coastal plain during a time of known sea-level changes, no depositional sequences can be recognized in the NCM, due to high rates of accommodation and sediment supply. The repeated co-occurrence of southward-trending major channel belts across the Newcastle coalfield is attributed to the area being located in the axial foredeep of the basin. A new palaeogeographic reconstruction is proposed in which the northern Sydney Basin, in the late Permian, extended further northwards across what is now the southern New England Orogen, and the north-south-elongate basin was drained by continental scale, basin-axial river systems that carried significant volumes of gravel.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"307 ","pages":"Article 104829"},"PeriodicalIF":5.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144337817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The evolution of interdunal peat-forming environments in the Maputaland coastal plain, Mozambique","authors":"Marios Panagiotis Chrysochos ,&nbsp;Stavros Kalaitzidis ,&nbsp;Mussa Achimo ,&nbsp;Lopo Vasconcelos ,&nbsp;Chrysoula Chrysakopoulou ,&nbsp;Kimon Christanis","doi":"10.1016/j.coal.2025.104828","DOIUrl":"10.1016/j.coal.2025.104828","url":null,"abstract":"<div><div>In the Elephant Game Reserve (EGR) in Mozambiquan Maputaland, several small peatlands have been developed between dunes. The aim of the study is to determine the peat-forming conditions and elucidate the evolution of the peatlands. Herbaceous vegetation (reeds and sedges) thrive on the surface of the mires. Fifty-five organic and inorganic samples were picked up from nine manually-retrieved cores up to 4.4 m deep, across several locations in the EGR. The maximum thickness of the organic sediments is 2.5 m. The determinations performed included proximate and ultimate analyses, pH and electrical Conductivity (eC) measurements, organic-petrography examination, as well as mineralogical and geochemical analyses applying X-ray diffraction and X-ray fluorescence spectrometry, respectively. The peat samples display ash yields between 10.1 and 46.8 % (on dry basis), sulphur content up to 8.9 % (db), pH and eC values from 2-7.3 and 142–2360 μS/cm, respectively. Quartz, K-feldspars and pyrite are the major minerals contained in peat; accordingly, silica is the major element with iron, aluminum, calcium and magnesium being minors. The maceral composition of peat reveals the predominance of the huminite group (57.6–78.6 vol%, on mineral matter-free basis), followed by inertinite (13.8–38.2 vol%) and liptinite (&lt;9.6 vol%). The prevalence of the detrohuminite subgroup, particularly of attrinite, along with inertodetrinite, points to intense mechanical decomposition of the plant remains and periodical lowering of the local watertable with subsequent fires, during which the mire surface was exposed to oxidation. Overall, peat accumulation took place under rheo- to mesotrophic conditions.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"307 ","pages":"Article 104828"},"PeriodicalIF":5.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144513683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrocarbon generation potential and organic carbon enrichment in evaporitic lacustrine source rocks from the Qianjiang Formation, Jianghan Basin (Central China): An integrated geochemical-petrological investigation","authors":"Rongbin Yang ,&nbsp;Qingyong Luo ,&nbsp;Jiapeng Wu ,&nbsp;Qixiang Huang ,&nbsp;Man Lu ,&nbsp;Wenxin Hu ,&nbsp;Dandan Wang ,&nbsp;Zhengyu Chen ,&nbsp;Jinqi Qiao","doi":"10.1016/j.coal.2025.104827","DOIUrl":"10.1016/j.coal.2025.104827","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Continental hypersaline lacustrine basins constitute critical repositories of unconventional shale oil resources, often hosting source rocks with primary exploration value. The hydrocarbon generation potential and organic matter accumulation within the Qianjiang Formation of Jianghan Basin, however, remain elucidated inadequately. This study targets the third member of the Qianjiang Formation (Eq&lt;sup&gt;3&lt;/sup&gt;) through systematic analysis of dolomitic shale sequences from the QYP1 directional well in Qianjiang Depression. A comprehensive analytical approach is employed, integrating programmed open-system pyrolysis, major and trace element geochemistry, biomarker analysis, and organic petrology. The multidisciplinary framework is utilized to evaluate sediment provenance, organic matter supply, paleoenvironmental reconstruction (including paleoclimate, redox condition, and paleosalinity) during the Eq&lt;sup&gt;3&lt;/sup&gt; depositional period, and the thermal maturity of organic matter. Based on these influencing factors, the hydrocarbon generation potential and organic matter enrichment model for source rocks of the Eq&lt;sup&gt;3&lt;/sup&gt; interval are assessed.&lt;/div&gt;&lt;div&gt;Results demonstrate that the organic-rich sediments of the Eq&lt;sup&gt;3&lt;/sup&gt; shales in the Qianjiang Depression exhibit exceptional hydrocarbon potential, qualifying as prime targets for shale oil exploration. Key characteristics include elevated total organic carbon (TOC), elevated S&lt;sub&gt;1&lt;/sub&gt; + S&lt;sub&gt;2&lt;/sub&gt; values, and superior hydrogen index (HI). Primary source of organic matter is attributed to saline lacustrine algae, as evidenced by a strong linear correlation between liptinite and TOC content and high proportion of lamalginite. The analyzed organic matter exhibits thermal maturity levels ranging from immature to low-mature level. Organic matter enrichment in these evaporative lacustrine source rocks is controlled by a combination of factors, including paleoclimate, sediment supply, organic matter sources, and depositional conditions. Paleoclimate reconstructions indicate that the Eq&lt;sup&gt;3&lt;/sup&gt; interval was deposited under cold and arid conditions, with low Ga/Rb, SiO&lt;sub&gt;2&lt;/sub&gt; and high K&lt;sub&gt;2&lt;/sub&gt;O/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; + K&lt;sub&gt;2&lt;/sub&gt;O + Na&lt;sub&gt;2&lt;/sub&gt;O, accompanied by weak chemical weathering with minimal sediment recycling. Depositional environment demonstrates strongly reducing conditions and exceptional organic matter preservation, as indicated by low Pr/Ph ratios, exceptionally high Gamm/C&lt;sub&gt;30&lt;/sub&gt; (βα + αβ) hopane indices, rominent extended tricyclic terpanes ratios (ETR) and widespread pyrite occurrence. Elevated gammacerane, &lt;em&gt;β&lt;/em&gt;-carotane content, along with high Sr/Ba, B/Ga and DBT/P radios, suggest high paleosalinity. Water column stratification further enhanced paleoproductivity and provided optimal conditions for organic matter preservation. Hydrocarbon-generating organic matter is predominantly derived from aquatic alga","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"307 ","pages":"Article 104827"},"PeriodicalIF":5.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144511107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}