Chet R. Bhatt,Jinesh C. Jain,Alexander A. Bol'shakov,Dustin L. McIntyre
{"title":"Corrigendum to ‘Chemistry imaging and distribution analysis of rare earth elements in coal using LIBS and LA-ICP-MS instruments’ Int. J. Coal Geol. Volume 301 (2025) 104710","authors":"Chet R. Bhatt,Jinesh C. Jain,Alexander A. Bol'shakov,Dustin L. McIntyre","doi":"10.1016/j.coal.2026.105099","DOIUrl":"https://doi.org/10.1016/j.coal.2026.105099","url":null,"abstract":"","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"203 1","pages":"105099"},"PeriodicalIF":5.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895197","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}
Sandra Manosalva, Erika Amaya, Mauricio Alberto Bermúdez, Wilson Naranjo, Jorge Mariño, Juan Sebastian Gomez-Neita
{"title":"Thermal history of the Upper Cretaceous-Paleocene Guaduas Formation, Eastern Cordillera Basin of Colombia: implications for timing of coalification","authors":"Sandra Manosalva, Erika Amaya, Mauricio Alberto Bermúdez, Wilson Naranjo, Jorge Mariño, Juan Sebastian Gomez-Neita","doi":"10.1016/j.coal.2026.105100","DOIUrl":"https://doi.org/10.1016/j.coal.2026.105100","url":null,"abstract":"The Guaduas Formation (Upper Maastrichtian–Lower Paleocene) is the principal source of thermal and coking coal in the Eastern Cordillera Basin of the Colombian Andes. This study integrates proximate analyses and mean random vitrinite reflectance (VRr%) from 64 coal samples with thermal history modeling, subsidence analysis, and estimates of eroded section thickness to reconstruct the burial and thermal evolution of the Checua-Lenguazaque Syncline (CLS) coalfield. Ash and sulfur contents varied across the area and depend mainly on paleoenvironments, while moisture, volatile matter, and fixed carbon are rank-dependent and related to stratigraphic depth and folding. VRr% values show marked spatial variability, ranging from 0.68 to 1.60 (equivalent to 105.4 to 173.1 °C in maximum paleotemperature). This reflects contrasting burial, thermal, and tectonic histories across the basin, resulting in distinct local coalification patterns. Modeling indicates that the Guaduas Formation reached maximum burial depths consistent with the erosion of at least 1600 m of overlying strata and experienced prolonged residence near hydrocarbon-generation temperatures, with locally variable thermal histories. Reheating episodes broadly coincide with regional subsidence affecting adjacent sedimentary basins, whereas the latest cooling phase is consistent with post-Miocene exhumation of the Colombian Andes during the Andean orogeny. These results indicate that regional burial and exhumation were the dominant controls on local coalification patterns and coal rank variability. However, the timing and magnitude of individual thermal events remain model-dependent.","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"35 1","pages":""},"PeriodicalIF":5.6,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148884592","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: Updating the aims and scope of International Journal of Coal Geology","authors":"Shifeng Dai","doi":"10.1016/j.coal.2026.105051","DOIUrl":"10.1016/j.coal.2026.105051","url":null,"abstract":"","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"323 ","pages":"Article 105051"},"PeriodicalIF":7.3,"publicationDate":"2026-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148289471","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}
Jeisson Fabian Sanabria Vargas, Taís Freitas da Silva, Marcos Müller Bicca, Henrique De Maman Anzolin, Gianni Gisele Perin, Wolfgang Kalkreuth, André Lucas Batista de Lima, Gabriel Avila Dias Link, Juan Sebastian Gomez-Neita
{"title":"Geochemical variability of organic matter composition in marine deposits affected by heat of igneous intrusions, Paraná Basin – southern Brazil","authors":"Jeisson Fabian Sanabria Vargas, Taís Freitas da Silva, Marcos Müller Bicca, Henrique De Maman Anzolin, Gianni Gisele Perin, Wolfgang Kalkreuth, André Lucas Batista de Lima, Gabriel Avila Dias Link, Juan Sebastian Gomez-Neita","doi":"10.1016/j.coal.2026.105055","DOIUrl":"10.1016/j.coal.2026.105055","url":null,"abstract":"<div><div>Depositional conditions, thermal evolution, and post-depositional alteration processes control organic geochemical signatures preserved in sedimentary rocks. This study investigates the geochemical variability of organic matter and hydrocarbon composition in shale, marlstone, and siltstone influenced by the thermal effects of igneous intrusions within the Permian succession of the Paraná Basin, Brazil. This interval corresponds to the most significant anoxic event recorded in the basin and represents an important organic-rich succession within the Gondwana stratigraphic record. The study area is located along the southeastern margin of the basin, near the rifted South Atlantic margin. Core samples from borehole CBM-003-ST-RS were collected at varying distances from an approximately 18-m-thick diabase sill and analyzed using an integrated approach that combined random vitrinite reflectance (VRr), open-system pyrolysis, and molecular biomarker analyses.</div><div>Based on lithology, organic matter characteristics, and distance from the intrusion, four sample zones (A, B, C, and D) were defined. The results reveal a clear thermal gradient consistent with conductive heat transfer from the sill. Zones A and B, located within the first 17 m from the contact, exhibit strong thermal alteration of organic matter, with VRr values of 1.02–3.11% and T<sub>max</sub> values of 437–470 °C. These samples display low Total Organic Carbon (TOC) contents (< 1 wt%) and very low S<sub>1</sub> and S<sub>2</sub> values (< 0.5 mg HC/g rock), indicating severe depletion of hydrocarbon-generating potential. Molecular parameters also indicate intense thermal stress, including the absence of pristane and phytane, marked alterations in biomarker ratios, and significant changes in polycyclic aromatic hydrocarbon (PAH) distributions, characterized by the predominance of fluoranthene and pyrene. Variations in phenanthrene and methylphenanthrene isomers further indicate advanced thermal maturity. In contrast, samples located 17.65–33.35 m from the intrusion (Zones C and D) show limited thermal influence. These intervals display VRr values of 0.7–0.8%, consistent with the onset of the hydrocarbon generation window, and preserve relatively stable biomarker ratios and PAH distributions. Sterane distributions (C₂₇–C₂₉) and the presence of gammacerane indicate a predominantly marine-transitional depositional environment under moderate salinity conditions. Elevated GAM/C₃₀ hopane in some samples from Zone C suggests deposition in relatively shallow-water environments where carbonates were interbedded with organic-rich shales. These results are consistent with biomarker data reported from other sectors of the basin where equivalent strata were not affected by igneous heating, indicating that key depositional signals may remain preserved despite localized thermal overprinting. The Irati Formation, therefore, represents an example of molecular resilience in organic-rich s","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"323 ","pages":"Article 105055"},"PeriodicalIF":7.3,"publicationDate":"2026-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148313339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Geochemical and mineralogical characteristics of magma-influenced early Permian coals from the Huanghebei coalfield, North China: provenance and critical element redistribution","authors":"Minglian Shen, Yuzhen Zhu, Huaihong Wang, Dongdong Wang, David French, Minglei Zhou, Lijun Shen, Yunhe Lv, Xue Liu, Xinbin Zhang, Chao Sun","doi":"10.1016/j.coal.2026.105053","DOIUrl":"10.1016/j.coal.2026.105053","url":null,"abstract":"<div><div>The western Shandong region, a component of the North China Craton (NCC), is a major coal-producing area extensively affected by magmatic-hydrothermal activities, which also hosts abundant coal-associated mineral resources. However, the relationships between magmatic intrusion and the mineralogical/geochemical compositions of Early Permian coals and associated rocks in the Huanghebei Coalfield (HHBC), alongside sediment source shifts and the redistribution of critical elements, remain poorly understood. To address these gaps, coal, mudstone and sandstone samples from drillhole ZK12 were analyzed via XRD, ICP-OES, ICP-MS, and TIMA. Results show that the sediments are primarily derived from the Yinshan paleoland. Distinct geochemical variations in Al₂O₃/TiO₂ ratios among samples suggest rapid provenance shifts during the Early Permian, indicating a tectonically active and unstable basin setting. Hydrothermal minerals such as vein-like hematite and kaolinite provide robust evidence for magmatic-hydrothermal overprinting. This hydrothermal activity significantly elevated coal rank and promoted the redistribution of some critical elements, without causing their pronounced overall enrichment. Thermal decomposition of dolomite and ankerite and magmatically induced carbon redeposition artificially elevate volatile matter contents, leading to biased estimates of volatile yield and coal rank; thus, vitrinite reflectance serves as the most reliable coal-rank indicator for magmatic-hydrothermally altered coal. Given that this study only analyzed six samples from a single drillhole, thus expanded sampling and further research are required to verify and consolidate these conclusions.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"323 ","pages":"Article 105053"},"PeriodicalIF":7.3,"publicationDate":"2026-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148289600","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}
Ke Zhang, Songhang Zhang, Wenguang Tian, Shuheng Tang, Minfang Yang, Kun Zhang, Dongping Zhao, Jiang Chen
{"title":"Chemical distribution characteristics and controlling factors of high-salinity produced water from deep coal seam in the Benxi Formation of the central-eastern Ordos Basin, China","authors":"Ke Zhang, Songhang Zhang, Wenguang Tian, Shuheng Tang, Minfang Yang, Kun Zhang, Dongping Zhao, Jiang Chen","doi":"10.1016/j.coal.2026.105054","DOIUrl":"10.1016/j.coal.2026.105054","url":null,"abstract":"<div><div>The geochemical characteristics of produced water from deep coalbed methane (CBM) provide information about CBM accumulation and preservation. Currently, the formation mechanisms and spatial distribution of high-salinity water in high-temperature, high-pressure deep coal reservoirs remain insufficiently understood. This study focuses on the No. 8 coal seam of the Benxi Formation in the central-eastern Ordos Basin. Based on hydrochemical and statistical analyses of water samples from 17 wells, the spatial distribution and geological controls of deep high-salinity water are identified. The results show that the produced waters, interpreted to largely represent coal seam waters (CSW) after sufficient flowback, are mainly CaCl<sub>2</sub>-type saline waters and brines, with total dissolved solids (TDS) ranging from 26.61 g/L to 151.7 g/L, indicating strong evaporation and concentration processes. The mineral saturation indices (SI) suggest that continuous halite dissolution is the main source of Na<sup>+</sup> and Cl<sup>-</sup>, whereas calcite, dolomite, and gypsum are consistently oversaturated. Spatial variations in hydrochemical coefficients (sodium chloride coefficient, desulfurization coefficient, metamorphism coefficient, and cation exchange coefficient) reveal a gradual increase in hydrological confinement from east to west across the study area. The spatial distribution of high-salinity water is controlled by multiple geological factors, such as the coupling effect of the sedimentary environment and roof lithology, thermal hydrocarbon generation, and the synergistic influence of coal reservoir properties and maceral composition. Furthermore, a three-stage hydrochemical evolution model covering shallow burial, ultra-deep burial, subsidence, and uplift is established to illustrate the dynamic fluid evolution. This study provides hydrochemical evidence for understanding hydrodynamic sealing and gas enrichment in deep CBM reservoirs.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"323 ","pages":"Article 105054"},"PeriodicalIF":7.3,"publicationDate":"2026-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148289567","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}
Leszek Marynowski, Dorota Staneczek, Katarzyna Dudzisz, Arkadiusz Derkowski, Jochen J. Brocks
{"title":"Basalt meets shale: The role of lava flow in the alteration of organic-rich host rocks","authors":"Leszek Marynowski, Dorota Staneczek, Katarzyna Dudzisz, Arkadiusz Derkowski, Jochen J. Brocks","doi":"10.1016/j.coal.2026.105052","DOIUrl":"10.1016/j.coal.2026.105052","url":null,"abstract":"<div><div>Organic-rich Miocene mudrocks from the Grabiszyce quarry (southwest Poland) provide a rare natural laboratory for investigating the short-term thermal effects of a basaltic lava flow on immature organic matter (OM) and mineral phases. Samples were collected along a decimeter to meter-scale transect from the basalt–sediment contact and analyzed using organic geochemistry, Rock-Eval, vitrinite reflectance, rock magnetism, and detailed clay mineralogy. Total organic carbon values are the lowest close to the lava contact (∼5 wt%) and increase to >10 wt% at distances greater than c.a. 0.3–1 m, consistent with thermal degradation of OM. Vitrinite reflectance increases sharply towards the basalt, from ∼0.20% Rr to 1.38% Rr within 2–5 cm of the contact, whereas <em>T</em><sub>max</sub> values (425–430 °C) remain low or could not be determined near the contact due to very low S2 yields. Hydrogen Indices decrease from 180 mg HC g<sup>−1</sup> TOC in immature samples to as low as 6 mg HC g<sup>−1</sup> TOC at the contact.</div><div>Molecular compositions show consistent loss of thermally labile compounds and enrichment in stable polycyclic aromatic hydrocarbons towards the lava flow, while unusually unstable biomarkers (e.g., ββ-hopanes) persist in thermally altered samples, reflecting kinetic inhibition during rapid heating. The preservation limit of tocopherols is constrained to ∼0.3–0.4% Rr. Rock magnetic parameters show changes consistent with distance towards the lava flow. Enhanced formation of superparamagnetic magnetite within ∼35 cm of the basalt is documented, which correlates well with PAH concentrations and biomarker maturity ratios. Furthermore, clay mineralogy reveals no illitization of smectite, despite elevated organic maturity, indicating a fluid-deficient, short-lived thermal pulse that is insufficient to trigger potassium-driven mineral reactions. These results demonstrate that OM and magnetic mineralogy respond more rapidly than clay minerals to brief, high-temperature events, highlighting a fundamental decoupling between organic and inorganic maturity indicators under contact metamorphic conditions.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"323 ","pages":"Article 105052"},"PeriodicalIF":7.3,"publicationDate":"2026-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148289602","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":"Corrigendum to “Influence of altered volcanic ash on lithium enrichment in Late Carboniferous coals in Odors Basin, North China: Insights from LA-ICP-MS and lithium isotope data” [Int. J. Coal Geol. 320 (2026) 104999]","authors":"Jiaming Zhang , Zhibo Zhang , Yinghai Guo , Difei Zhao , Yilin Chen , Zhuoxi Liu","doi":"10.1016/j.coal.2026.105011","DOIUrl":"10.1016/j.coal.2026.105011","url":null,"abstract":"","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"321 ","pages":"Article 105011"},"PeriodicalIF":5.7,"publicationDate":"2026-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147735998","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}
Xiaodong Liu , Wanglu Jia , Qiang Wang , Jinbu Li , Jian Chen , Ping'an Peng
{"title":"Hydrogen distributions during thermal maturation of organic-rich sedimentary rocks: Generation potentials and influencing factors of hydrogen-bearing gases revealed by pyrolysis","authors":"Xiaodong Liu , Wanglu Jia , Qiang Wang , Jinbu Li , Jian Chen , Ping'an Peng","doi":"10.1016/j.coal.2026.104965","DOIUrl":"10.1016/j.coal.2026.104965","url":null,"abstract":"<div><div>Hydrogen derived from organic-rich sedimentary rocks plays important roles in conventional and green energy applications, energy utilization, and atmospheric pollution. Although thermal simulation experiments have preliminarily revealed the mechanisms of hydrogen generation, the understanding of its migration from source rocks and accumulation processes remains scarce, which severely constrains exploration practices. This study conducted high-pressure gold-tube (closed-system) pyrolysis at 600 °C to investigate three series of source rocks with different maturities, obtained by artificial maturation. The work examined the amount of hydrogen generated during pyrolysis of source rocks. We carefully quantified hydrogen in its multiple phases and evaluated the influencing factors of hydrogen-bearing gases and H<sub>2</sub> generation potential. Firstly, organic hydrogen (TOH) contents for up to 36.2–72.2% of total hydrogen (TH) in low-mature original source rocks. When thermally evolved to a high maturity (Easy %Ro 1.98), a significant reduction in TOH is observed (by 62–76% of the original TOH), while the inorganic hydrogen (TIH) remains relatively stable. Moreover, when source rocks evolved to Easy %Ro 4.45, hydrogen is primarily converted into CH<sub>4</sub> (up to 40.8% relative to the TH of original source rocks), much higher than H<sub>2</sub> (up to 1.2%). In contrast, in high‑sulfur source rocks, due to the competition of sulfur for hydrogen, the percentage of hydrogen in H<sub>2</sub>S generated (5.8%) exceeds that of H<sub>2</sub>. Secondly, the yields of H<sub>2</sub> and CH<sub>4</sub> exhibit a strong positive linear correlation with HI values of Rock-Eval analysis, whereas H<sub>2</sub>S yields also depend on the source rock's sulfur content. For type I kerogen with significantly higher HI, the H<sub>2</sub> yield is greater than that of type II. However, for samples classified as type II kerogen, the HI value alone does not fully indicate the magnitude of H<sub>2</sub> yield. The thermal maturation process alters the organic matter structure, thereby changing the H<sub>2</sub> generation characteristics of different source rocks. Moreover, H<sub>2</sub> and CH<sub>4</sub> generation is influenced by the pyrolysis conditions. Open-system pyrolysis generally exhibits higher H<sub>2</sub>/CH<sub>4</sub> molar ratios than closed-system pyrolysis, which may be due to much higher temperatures adopted in open-system pyrolysis, as well as the occurrence of hydrogenation reactions in closed systems. Finally, hydrogen distribution analysis indicates that source rocks retain significant H<sub>2</sub> generation potential even with thermal evolution to a post-mature stage (Easy %Ro > 4.45), with a maximum yield of approximately 7.4–25.5 mg/g TOC upon complete conversion of residual organic hydrogen to H<sub>2</sub>. Notably, post-mature source rocks, initially having type II kerogen rich in condensed aromatic structures, demonstrate a","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"316 ","pages":"Article 104965"},"PeriodicalIF":5.7,"publicationDate":"2026-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160593","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}
Jorge Eliecer Mariño-Martinez , Tim A. Moore , Juan Sebastian Gomez-Neita
{"title":"Coal bed gas in Colombia: Current status","authors":"Jorge Eliecer Mariño-Martinez , Tim A. Moore , Juan Sebastian Gomez-Neita","doi":"10.1016/j.coal.2026.104945","DOIUrl":"10.1016/j.coal.2026.104945","url":null,"abstract":"<div><div>Coalbed methane (CBM) has garnered growing attention in Colombia due to declining conventional energy resources and reserves, persistent mining accidents caused by methane explosions, and climate regulations aimed at reducing greenhouse gas (GHG) emissions. This study provides a review of the current status of CBM in Colombia, synthesizing geological, geochemical, and technical data to assess its development potential. Despite the significant coal reserves of Colombia, early CBM resource estimates were overly optimistic. Updated evaluations reveal that most coal seams exhibit low gas contents (<200 ft<sup>3</sup>/ton - 5.66 m<sup>3</sup>/ton), having gas saturations typically less than 50%. This level of gas content poses particular challenges for commercial development. In Colombia, four provinces or coal zones—Cundinamarca, Boyacá, Cesar, and La Guajira—show localized potential, with some samples exceeding 300 ft<sup>3</sup>/ton. However, reservoir modeling, particularly from the Umbita-Chinavita area (Boyacá), demonstrates that low permeability (<10 mD), thin and discontinuous coalbeds, and structural complexity may inhibit development. The gas quality in these areas also varies, with a methane content averaging 75%, which also places additional pressure on commerciality. Isotopic and hydrogeological analyses suggest a predominantly biogenic origin of methane, often linked to meteoric recharge of the aquifers. Despite technical promise, development faces significant barriers, including inconsistent laboratory standards for existing historical data, a lack of clear legal frameworks, insufficient infrastructure, and limited investor interest and research. Regulatory and institutional fragmentation between coal and gas authorities further complicates the management of CBM resources. To unlock the CBM potential, Colombia must implement standardized exploration practices, develop robust incentive structures, and conduct comprehensive feasibility studies incorporating desorption, adsorption, and isotopic data. This work concludes that while Colombia possesses notable CBM resources, substantial technical, economic, and regulatory challenges must be overcome before near-term commercial production can be realized. The findings provide a foundation for future exploration, policy reform, and sustainable energy strategies aligned with national safety and environmental goals.</div></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":"316 ","pages":"Article 104945"},"PeriodicalIF":5.7,"publicationDate":"2026-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995726","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}