International Journal of Coal Geology最新文献

{"title":"Geological factors for the enrichment of critical elements within the Lopingian (Late Permian) coal-bearing strata in western Guizhou, Southwestern China: Constrained with whole-rock and zircon geochemistry","authors":"Tianyang Yang ,&nbsp;Yulin Shen ,&nbsp;Lu Lu ,&nbsp;Jun Jin ,&nbsp;Wen Huang ,&nbsp;Fayue Li ,&nbsp;Yunfei Zhang ,&nbsp;Jiangchen Hu ,&nbsp;Lijun Zeng","doi":"10.1016/j.coal.2023.104441","DOIUrl":"10.1016/j.coal.2023.104441","url":null,"abstract":"<div><p><span><span>A number of volcanic ash-bearing layers deposited in the Upper Permian<span> coal-bearing strata on the southwestern margin of the Yangtze Craton are well preserved, and some layers show the enrichment of critical elements such as an assemblage of Zr(Hf)–Nb(Ta)–Ga–REE (REE, rare earth elements). Based on previous work, we studied the source of the Upper Permian volcanic ash-bearing layers widely distributed in western to northwestern Guizhou and the geological factors for the enrichment of critical elements. This article provides a detailed analysis of the mineralogical and geochemical characteristics of the Upper Permian volcanic ash-bearing layers. The </span></span>mineralogy<span><span><span> of the samples is dominated by clay minerals, quartz, anatase, plagioclase, and pyrite, with a few containing K-feldspar, </span>calcite<span><span>, dolomite, and siderite. The clay minerals are mainly composed of mixed-layer illite/smectite (I/S) and </span>kaolinite. The whole </span></span>rock geochemistry (Al</span></span>₂O₃/TiO₂, Nb/Ta vs. Zr/Hf, Nb/Al₂O₃ vs. Zr/Al₂O₃, and Th/Al₂O₃ vs. Zr/Al₂O₃<span><span><span><span>) and zircon trace elements (Th/Nb vs. Hf/Th, Nb/Yb vs. U/Yb, Ta vs. Nb, and Yb/Sm vs. Y) were used to help determine the source. The results indicate that the sources of the samples include Emeishan high-Ti </span>basalt<span><span>, intraplate volcanic ash from the Emeishan large igneous province (ELIP), and arc volcanic ash. The critical elements (Zr[Hf]–Nb[Ta]–REE) are mainly derived from the syndepositional intraplate volcanic ash erupted from the ELIP. The results of zircon trace elements and Hf </span>isotope ratios suggest that the </span></span>magma from the ELIP has gradually evolved from the mantle to the crust, and became more enriched in critical elements such as Nb and Ta. The intraplate volcanic ash from ELIP is the main supplier of critical elements and plays a crucial role in their enrichment through the Late Permian in southwestern China. The </span>paleoenvironment<span> controlled the deposition of volcanic ashes, and most of the critical element enrichment layers developed in weak hydrodynamic<span><span> environments. The paleogeography and acid rain influenced the migration of critical elements such as Nb, Ta, </span>REE, and Y in some layers. The enrichment of critical elements is also controlled by the regularity and intensity of intraplate volcanic activity.</span></span></span></p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139081839","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":"Effect of ScCO2-H2O treatment duration on the microscopic structure of coal reservoirs: Implications for CO2 geological sequestration in coal","authors":"Yarui Guan ,&nbsp;Zhe Zhou ,&nbsp;Zhaolong Ge ,&nbsp;Qinglin Deng ,&nbsp;Yunzhong Jia ,&nbsp;Shan Huang ,&nbsp;Changjiang Chen ,&nbsp;Shihui Gong","doi":"10.1016/j.coal.2023.104439","DOIUrl":"10.1016/j.coal.2023.104439","url":null,"abstract":"<div><p><span>The microstructure of coal reservoirs, especially the pore structure, alters as a result of physicochemical reactions between the CO</span>₂ acidic fluid and coals. However, it is still unclear what controls this process and how the pore structure properties of coal alter by the action of CO₂<span><span> acid fluids change over time. The objective of this study is to identify the underlying mechanism by analyzing the changes in the mineral composition, surface roughness<span>, as well as micropore and mesopore structure of </span></span>anthracite<span> and bituminous coal<span> when exposed to supercritical CO</span></span></span>₂ (ScCO₂)-H₂<span>O. The results indicate that coal reservoirs primarily undergo processes of adsorption expansion and mineral dissolution/precipitation. Among these, adsorption expansion concluded or weakened after 7 days, with mineral precipitation gradually becoming the dominant factor, which results in more secure geological CO</span>₂ storage (GCS). Furthermore, comparative analysis of anthracite and bituminous coal with untreated and long-term treatment demonstrates that anthracite exhibits higher CO₂<span><span> storage capacity and greater wettability. Consequently, anthracite is more suitable as a target reservoir for GCS compared to bituminous coal. These results, therefore, offer a theoretical foundation and a guide for choosing GCS sites in deep un-minable </span>coal seams.</span></p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139060798","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":"Modes of occurrence of gallium in Al-Ga-rich coals in the Jungar Coalfield, Ordos Basin, China: Insights from LA-ICP-MS data","authors":"Bo Jiu ,&nbsp;Zhijun Jin ,&nbsp;Zhaoguo Wang ,&nbsp;Runchao Liu ,&nbsp;Qitu Hu","doi":"10.1016/j.coal.2023.104436","DOIUrl":"10.1016/j.coal.2023.104436","url":null,"abstract":"<div><p><span><span><span>Owing to the concern about supply of Ga, it has been attracted much attention for the modes of occurrence of Ga in Al-Ga-rich coal-hosted deposits. However, the modes of occurrence of Ga in coal were mainly investigated using indirect methods, which may cause uncertainties. In this study, laser ablation </span>inductively coupled plasma mass </span>spectrometry<span> (LA-ICP-MS) spot and mapping analysis were used to directly characterize the concentration of Ga within the host minerals including kaolinite<span><span> and boehmite, and to investigate the distribution of Ga in organic matter in the Carboniferous Al-Ga-rich coal from the Haerwusu Mine in the Jungar Coalfield of the Ordos Basin, North China. Microscope observation and scanning </span>electron microscope<span> - energy dispersive spectrometry (SEM-EDS) analysis were performed, along with petrographical and mineralogical investigations. Eight types of kaolinite and three types of boehmite particles from coal, erosional-sourced mudstone, and tonstein were identified, classified, and selected for the determination of </span></span></span></span><em>in-situ</em><span> elemental compositions.</span></p><p>The results showed that the concentration of Ga in the selected minerals varies, with the following order from highest to lowest: colloidal boehmite (90.38 ppm), low-Al (Al₂O₃/SiO₂<span>) clastic kaolinite (84.67 ppm), high-Al clastic kaolinite (55.49 ppm), Na-bearing kaolinite (49.94 ppm), fine-grained boehmite (47.13 ppm), high-Al cryptocrystalline<span> kaolinite (40.25 ppm), low-Al cryptocrystalline kaolinite (38.78 ppm), and low-Al vermicular kaolinite (29.67 ppm), high-Al vermicular kaolinite (28.37 ppm), K-bearing kaolinite (19.44 ppm), and clastic boehmite and cell-filling kaolinite (below detection limit). LA-ICP-MS mapping demonstrated that a certain proportion of Ga could be associated with organic matter, concentrating on vitrinite. Notably, the concentration of Ga in clastic kaolinite and colloidal boehmite was found to be substantially higher compared to the whole-rock coal and erosional-sourced mudstone samples, indicative of their dominant host minerals for Ga. Conversely, the concentration of Ga in K-bearing or Na-bearing kaolinite which had experienced transformation from primary kaolinite is much lower than that in clastic kaolinite, while the concentration of Ga in fine-grained boehmite, which had altered from kaolinite, surpassed that of its corresponding kaolinite layer. These findings suggest that gallium could have undergone migration during the evolution or alteration of clay minerals.</span></span></p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139060009","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":"Organic geochemistry and organic petrology of Oligocene and Miocene lignites, subbituminous and high volatile bituminous coals and carbonaceous shales in northern and central Trinidad","authors":"Anastasia A. Baboolal ,&nbsp;Ralf Littke ,&nbsp;Laura Zieger","doi":"10.1016/j.coal.2023.104437","DOIUrl":"10.1016/j.coal.2023.104437","url":null,"abstract":"<div><p>The so far unstudied Oligocene<span> and Miocene<span><span> organic matter–rich deposits of the Cunapo and Nariva Formation of northern and central Trinidad, western tropical Atlantic Ocean have been investigated using organic geochemical and organic petrological techniques to assess the </span>thermal maturity<span><span> and paleoenvironmental conditions during peat accumulation. Twenty samples were collected along various sections within the Cunapo and Nariva formations. Evaluation based on organic petrological analyses and Rock-Eval pyrolysis reveals that the coals and carbonaceous shales are thermally immature in the </span>lignite<span> and subbituminous rank for Cunapo Formation and mature in the subbituminous to high-volatile bituminous rank for Nariva Formation. The respective maturities correspond to high volatile matter contents.</span></span></span></span></p><p><span>Petrographically, the Cunapo Formation coals are dominated by huminite with minor amounts of inertinite<span><span> and liptinite<span>, and the Nariva Formation coals contain high amounts of vitrinite, with moderate to low liptinite and low inertinite contents. The detailed petrographic data for Cunapo and Nariva coals indicate predominantely limnic conditions and a herbaceous </span></span>origin of organic matter. Further conclusions are deduced from petrographic ratios such as gelification-, tissue preservation-, vegetation- and groundwater</span></span>_AC<span> indices, ash- and sulfur contents<span>, iso- and n-alkane distribution, and 17α(H)-homohopane ratio. In summary, the data supports that both the Cunapo and Nariva coals formed in a tropical peat environment, partly influenced by very high microbial activity<span> and ± in case of Nariva coals - partly grading into ombrogenic mires. The Cunapo coals were influenced by the development of the Orinoco River system during the Miocene and exposure to marine water during transgressive phases in a tidal, coastal environment.</span></span></span></p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139059438","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":"Multi-tracer approach to constrain groundwater flow and geochemical baseline assessments for CO2 sequestration in deep sedimentary basins","authors":"Harald Hofmann ,&nbsp;Julie K. Pearce ,&nbsp;Phil Hayes ,&nbsp;Sue D. Golding ,&nbsp;Nick Hall ,&nbsp;Kim A. Baublys ,&nbsp;Matthias Raiber ,&nbsp;Axel Suckow","doi":"10.1016/j.coal.2023.104438","DOIUrl":"10.1016/j.coal.2023.104438","url":null,"abstract":"<div><p>Geological storage of gases will be necessary in the push to net zero and the energy transition to reduce carbon emissions to atmosphere. These include CO₂ geological storage in suitable sandstone reservoirs. Understanding groundwater flow, connectivity and hydrogeochemical processes in aquifer and storage systems is vital to prevent risk and protect important water resources, such as the Great Artesian Basin. Here, we provide a ‘tool-box’ of geochemical assessment methods to provide information on flow patterns through the basin's aquifers (changes in chemistry along flow path), stagnant versus flowing conditions (cosmogenic isotopes and noble gases), inter-aquifer connectivity and seal properties (major ions, Sr and stable isotopes), water quality (major ions and metals) and general assessments on residence times of groundwater (cosmogenic isotopes and noble gases). This information can be used with reservoir and groundwater models to inform on possible changes in the above-mentioned processes and serve as input parameters for CO₂ injection impact modelling. We demonstrate the use and interpretation on an example of a potential CO₂ storage geological sequestration site in the Surat Basin, part of the Great Artesian Basin, and the aquifers that overly the reservoir. The stable water isotopes are depleted compared to average rainfall and most likely indicate greater contributions from monsoonal rain events from the northern monsoonal troughs, where amount and rainout effects lead to the depletion rather than colder recharge climates. This is supported by the modern recharge temperatures from noble gases. Inter-aquifer mixing between the Precipice Sandstone reservoir and the Hutton Sandstone aquifer seems unlikely as the Sr isotope ratios are distinctly different suggesting that the Evergreen Formation is a seal in the locations sampled. Mixing, however, occurs on the edges of the basin, especially in the south-east and east where the Surat Basin transitions into the Clarence-Moreton Basin. Groundwater flow appears to be to the south in the Precipice Sandstone, with a component of flow east to the Clarence-Morton Basin. The cosmogenic isotopes and noble gases strongly indicate very long residence times of groundwater in the central south Precipice Sandstone around a proposed storage site. ¹⁴C values below analytical uncertainty, R³⁶Cl ratios at secular equilibrium as well as high He concentrations and high ⁴⁰Ar/³⁶Ar ratios support the argument that groundwater flow in this area is extremely slow or groundwater is stagnant. The results of this study reflect the geological and hydrogeological complexities of sedimentary basins and that baseline studies, such as this one, are paramount for management strategies.</p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0166516223002562/pdfft?md5=789c48b3ac6bf0b012217ea4726fbbb6&pid=1-s2.0-S0166516223002562-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139059661","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":"Factors controlling the heterogeneity of shale pore structure and shale gas production of the Wufeng–Longmaxi shales in the Dingshan plunging anticline of the Sichuan Basin, China","authors":"Yijun Zheng ,&nbsp;Yuhong Liao ,&nbsp;Jie Wang ,&nbsp;Yongqiang Xiong ,&nbsp;Yunpeng Wang ,&nbsp;Ping’an Peng","doi":"10.1016/j.coal.2023.104434","DOIUrl":"10.1016/j.coal.2023.104434","url":null,"abstract":"<div><p><span><span>Shale gas exploration in the Dingshan plunging </span>anticline of the Sichuan Basin, China, has uncovered substantial Wufeng–Longmaxi shale reserves. However, substantial variations exist in shale gas content and production among the wells in this region. We investigated the geological factors and mechanisms influencing shale pore structure heterogeneity and shale gas content and production in the area. We conducted comprehensive analyses of </span>mineralogy<span><span><span>, geochemical characteristics, and petrophysical properties on the Late Ordovician<span> Wufeng Formation–Early Silurian Longmaxi </span></span>Formation shales. Shale samples were collected from a shallow well, Anwen-1, located in proximity to the Qiyueshan </span>thrust fault<span><span><span> within the Dingshan plunging anticline. Additionally, samples from Dingye (DY) 1 and DY 3 wells, located at varying distances from the thrust fault, were examined. We also integrated previously published data from two correlative sections in the southeastern margin of the Sichuan Basin, each at different distances from the thrust fault. The pore volume, specific surface area, and porosity of the shales were positively correlated with their total organic content (TOC). However, strong lateral compressive stress, often occurring near the regional thrust fault, attenuated the linear relationship between </span>TOC<span> and pore volume/porosity. Lateral compressive stress did not significant affect shale porosity and pore structure when the distance from the regional thrust fault exceeded approximately 15 km. The specific surface area of the shale was less affected by compressive stress. Moreover, carbonate cementation<span> reduced porosity by sealing shale matrix pores and natural microfractures, reducing </span></span></span>nanopore connectivity. Consequently, shale gas production is not solely influenced by shale gas content but is also significantly affected by carbonate cementation. Therefore, shale reservoirs located at relatively long tectonic distances from regional thrust faults (approximately 15 km) within the Dingshan plunging anticline exhibit high pore volume, porosity, and shale gas content, rendering them favorable for shale gas exploration.</span></span></p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139041605","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":"Coal structure identification based on geophysical logging data: Insights from Wavelet Transform (WT) and Particle Swarm Optimization Support Vector Machine (PSO-SVM) algorithms","authors":"Zhongzheng Tong ,&nbsp;Yanjun Meng ,&nbsp;Jinchuan Zhang ,&nbsp;Yaning Wu ,&nbsp;Zhen Li ,&nbsp;Dongsheng Wang ,&nbsp;Xingqi Li ,&nbsp;Guangxi Ou","doi":"10.1016/j.coal.2023.104435","DOIUrl":"10.1016/j.coal.2023.104435","url":null,"abstract":"<div><p><span><span><span>Coal structure is closely related to microscopic and macroscopic properties<span><span> of coal, and its accurate identification is of great significance to coalbed methane (CBM) </span>reservoir evaluation, hydraulic fracturing performance and production efficiency prediction. The identification of coal structure based on geophysical logging data has become a popular topic as well as a challenge. The emerging Machine Learning (ML) provides convenience for this issue. Under this background, in the case of the Shanxi Formation No. 3 </span></span>coal seam and the Taiyuan Formation No. 15 coal seam in Mabidong Block, Qinshui Basin, China, this paper proposed a new coal structure identification method based on geophysical logging data using Wavelet Transform (WT) and </span>Particle Swarm Optimization<span><span> Support Vector Machine (PSO-SVM) algorithms. Our results showed that the vertical resolution of logging data can be effectively improved when sym5 wavelet basis and third </span>level decomposition<span> were selected in wavelet decomposition, and 4.5 was selected as the weighting coefficient in wavelet reconstruction. The coal structure prediction model based on the logging data processed by WT was established by PSO-SVM algorithm, where PSO was used for parameter optimization (optimal penalty factor </span></span></span><span><math><mi>C</mi></math></span> and width parameter <span><math><mi>σ</mi></math></span><span>) and SVM with Radial Basis Function (RBF) kernel was used for model establishment. The Hold-out Cross Validation (HO CV) method was used to test the generalization ability of the prediction model, and the accuracy (</span><span><math><mi>ACC</mi></math></span>) of coal structure prediction in the training set and testing set was 94.26% and 88.46%, respectively. The prediction model was applied to identify the coal structure of two coring wells and the predicted coal structure class was consistent with the true coal structure class, confirming the validity of the model. The coal structure prediction results in the whole study area showed that the tectonic conditions control the coal structure. This work provides new insights for coal structure identification.</p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139034633","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":"Physicochemical characteristics and oxidative potential of size-segregated respirable coal mine dust: Implications for potentially hazardous agents and health risk assessment","authors":"Yunfei Shangguan ,&nbsp;Xinguo Zhuang ,&nbsp;Xavier Querol ,&nbsp;Baoqing Li ,&nbsp;Natalia Moreno ,&nbsp;Pedro Trechera ,&nbsp;Patricia Córdoba Sola ,&nbsp;Gaëlle Uzu ,&nbsp;Jing Li","doi":"10.1016/j.coal.2023.104433","DOIUrl":"10.1016/j.coal.2023.104433","url":null,"abstract":"<div><p>The health risks associated with exposure to respirable dust in coal mines have been attracted much attention by an increasing number of researchers. However, the accurate identification of potentially hazardous agents in respirable dusts and the evaluation of the potential health risks arising from it still remains controversial to varying degrees. A comprehensive understanding of the physicochemical properties<span><span> of respirable dust is a prerequisite and an important basis for resolving this controversy. Therefore, in this study, the particle size distribution<span> and morphology, pore structure, mineralogical and geochemical patterns, and oxidative potential (OP) of respirable coal mine dust were comprehensively investigated. Stepwise multiple linear regression was employed to identify dust components driving OP, such as anatase, tobelite, quartz, and </span></span>ankerite, in respirable coal mine dust, along with Na, Ni, Se, W, and As. On this basis, we performed a single-factor risk prediction for different coal mines by considering factors that may impact miners' health, with the analyses yielding somewhat contradictory results. Therefore, a multifactor integrated prediction model is proposed using an entropy-based technique for order preference by similarity to the ideal solution to categorize coal mines in the study area into three risk categories, high-, medium-, and low-risk dust mines, which is important for the hierarchical classification and control of coal mines and for formulating appropriate dust prevention and control measures.</span></p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138943503","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":"Signature characteristics of coal geochemistry from the Eocene Tanjung Formation and the Miocene Warukin Formation, Barito Basin: Insights into geological control on coal deposition and future critical element prospection","authors":"Ferian Anggara ,&nbsp;Aulia Agus Patria ,&nbsp;Basuki Rahmat ,&nbsp;Haryo Wibisono ,&nbsp;Muhammad Zulfiqar Jihad Putera ,&nbsp;Himawan Tri Bayu Murti Petrus ,&nbsp;Feddi Erviana ,&nbsp;Esti Handini ,&nbsp;Donatus Hendra Amijaya","doi":"10.1016/j.coal.2023.104423","DOIUrl":"10.1016/j.coal.2023.104423","url":null,"abstract":"<div><p><span><span><span>In conjunction with implementing the Indonesian Act on coal downstream research and development, the geochemical characterization of the Barito Basin coals and an evaluation of the critical elements in coal and coal ashes compared with those found in conventional deposits must be fulfilled. This study documented the signature characteristics of the coal geochemistry<span> in the Barito Basin. Coals from Tanjung Formation mainly comprise huminite macerals and inorganic constituents are mainly dominated by </span></span>kaolinite, pyrite, quartz, </span>carbonate minerals (i.e.</span><em>,</em><span> calcite<span><span>, Sr-bearing carbonate), Ti-oxide minerals (anatase or rutile), chlorite, and apatite<span>. Meanwhile, the Warukin Fm is characterized by high contents of inertinite and inorganic materials comprising kaolinite, pyrite, and quartz. Moreover, the B3 seam from the Tanjung Fm shows normal slight enrichments for Hf, Zr, and V, demonstrating the highest </span></span>REY content of up to 194.56 ppm. Meanwhile, coal samples from the Warukin Fm show depletion in all the trace elements and REY.</span></span></p><p><span>The provenance source of the Barito Basin coals is derived from epiclastic mafic–intermediate volcaniclastic<span> rocks, including the Early Cretaceous Pitap and Haruyan Fm, which are mainly derived from low-Ti mafic </span></span>magmas<span><span>. Subsequently, marine water infiltration<span> during peat accumulation is subjected to the influence of the geochemical characteristics of coals from the Eocene Tanjung Fm, showing the transgressive settings. On the other hand, the </span></span>Miocene<span> Warukin Fm. represents a non-marine regressive setting during peat accumulation. Furthermore, local geological controls in the Eocene Tanjung Fm. may lead some roof, floor, parting and coals from B3 seam to critical elements enrichment (such as REY, Zr, Hf, and V), and their affinity is related to Ti-oxide minerals, aluminosilicates, and organic matter.</span></span></p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138823241","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":"Interactions between surface properties of pristine coals and the intrinsic microbial communities involved in methane formation","authors":"Anna Pytlak ,&nbsp;Katarzyna Jaromin-Gleń ,&nbsp;Agnieszka Sujak ,&nbsp;Anna Szafranek-Nakonieczna","doi":"10.1016/j.coal.2023.104422","DOIUrl":"10.1016/j.coal.2023.104422","url":null,"abstract":"<div><p><span>As climate change continues, there is growing interest in the biological, in situ conversion of coal to methane, which is a cleaner and more efficient source of energy. The purpose of this study was to reveal the relationship between the surface properties of coals and the intrinsic microbial communities<span> involved in methane formation. The material examined included nine coals varying in maturity and methane-bearing capacity. Compilation of data on wettability (θw) (measured by a sessile drop method) and microbial community composition (next-generation sequencing (NGS)) revealed that the occurrence of </span></span><em>Bacteroidetes</em>, <em>Firmicutes</em> and methanogenic <em>Euryarchaeota</em> was significantly, positively (<em>P &lt; 0.05</em>) correlated with θw of coal. The dependence was the opposite for <em>Actinobacteria</em><span><span>. These results suggest that the groups of microorganisms<span> responsible for the decomposition of organic matter in </span></span>bituminous coals<span> (hydrophobic) and lignites (hydrophilic) differ, which may impact methane formation in the seams. This is because </span></span><em>Bacteroidetes</em> and <em>Firmicutes</em> stimulate this process, while the influence of <em>Actinobacteria</em><span> is the opposite. Our work demonstrates for the first time the links between the surface properties of coals, geotectonic conditions, microbial ecophysiology and the methane-bearing capacity of the coals.</span></p></div>","PeriodicalId":13864,"journal":{"name":"International Journal of Coal Geology","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2023-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138657580","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}