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James C. Hower - One of the best experts on this subject based on the ideXlab platform.
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palynology organic petrology and geochemistry of the bell coal bed in western kentucky eastern interior illinois basin usa
International Journal of Coal Geology, 2019Co-Authors: Cortland F. Eble, James C. Hower, Stephen F Greb, David A Williams, Jennifer M K OkeefeAbstract:Abstract The Bell coal bed is one of the stratigraphically oldest coals (Atokan, Duckmantian) in the Illinois Basin that has been commercially mined and occurs near the Morrowan-Atokan boundary, which was a time of significant lithologic change in the basin. The Bell coal occurs as a series of discontinuous pods, in contrast to younger (Asturian) coals in the basin that are thicker and more extensive in occurrence. Thirty-two samples of coal and carbonaceous shale, collected from surface mine, outcrop, and drill core locations were analyzed geochemically, petrographically and palynologically to ascertain the origin of the Bell coal bed in western Kentucky. The Bell coal exhibits a great deal of variability in thickness and composition, both temporally and spatially. Based on ash yields, the Bell coal consists of intercalated layers of coal (≤25% ash), impure coal (>25 to 80%, mmf), with telovitrinite occurring more frequently than detrovitrinite and gelovitrinite. Certain layers, however, contain elevated amounts of liptinite and Inertinite. Among the Inertinite Macerals, examples of both fire (e.g., fusinite) and degradation (e.g., macrinite) origin are evident. Samples with elevated amounts of Inertinite are commonly, though not exclusively, high in ash, indicating that some of the Inertinite may be of allochthonous origin. Palynologically, the Bell coal is dominated by arborescent lycopod spores (avg. >70%), occurring primarily as Lycospora, with some samples containing increased proportions of spores and pollen from other Pennsylvanian plant groups. Samples with more heterogenous palynofloras commonly have elevated ash yields, indicating that some portion of the assemblages may be also of allochthonous origin. Collectively, the Bell coal is interpreted to have formed from a series of small, disconnected paleomires that were planar and topogenous with paleotopography having an influence on peat development. A planar, topogenous origin helps to explain the highly variable ash yields and sulfur contents. Accumulating peat, principally from arborescent lycopod source material, was mainly well-preserved, but punctuated with intervals marked by sediment influx, the development of more heterogeneous palynofloras and degradation and oxidation of the surficial peat by both biologic (decay) and abiotic (fire) processes.
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mississippian serpukhovian chesterian stage coals from the fluorspar district crittenden and caldwell counties kentucky petrological and palynological compositions and their indications for peat producing ecosystems
International Journal of Coal Geology, 2017Co-Authors: James C. Hower, Jennifer M K Okeefe, Cortland F. EbleAbstract:Abstract Serpukhovian Stage (Chesterian Stage in North American nomenclature) coals in western Kentucky are among the few occurrences of Mississippian coals in eastern North America. Thus, they provide a rare view of early Carboniferous peat-producing ecosystems. Petrographically, the coals are dominated by telovitrinites. Among the Inertinite Macerals, coprolitic macrinite provides evidence of arthropods fungal-degraded wood. Cutinite has an association with epiphyllous fungus. Owing to the relatively high spore contributions from arborescent Lycopsids, the coals bear a palynologic resemblance to the Pennsylvanian Langsettian through Asturian (Westphalian) coals preserved in the nearby Western Kentucky coalfield. The maceral assemblages, however, show a greater similarity to the Upper Pennsylvanian (Stephanian) coals in western Kentucky. With 66–67% total vitrinite and about 29% total Inertinite (dominated by fusinite + semifusinite) (both as volume percent, mineral-fee basis), the Mississippian coals have significantly lower vitrinite percentages than the Westphalian coals. The petrographic similarity is not paralleled by a floristic similarity as the Stephanian flora was marked by the absence of arborescent Lycopsids. Overall, the amount of Inertinites and the degradation suggested by a number of the Inertinite forms suggests that, not unexpectedly decay and degradation was an important contributor to the Mississippian coals. As with any coals, the Mississippian coals represent a story of preservation more than that of degradation and destruction, with degraded and poorly-preserved fusinite and semifusinite, coprolitic macrinite, and remnants of fungi being the ghosts of the destruction of the biomass.
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geochemical and mineralogical evidence for a coal hosted uranium deposit in the yili basin xinjiang northwestern china
Ore Geology Reviews, 2015Co-Authors: Shifeng Dai, Colin R. Ward, James C. Hower, David French, Jianye Yang, Huidong Liu, Trent M Garrison, Jennifer M K OkeefeAbstract:Abstract The petrological, geochemical, and mineralogical compositions of the coal-hosted Jurassic uranium ore deposit in the Yili Basin of Xinjiang province, northwestern China, were investigated using optical microscopy and field emission-scanning electron microscopy in conjunction with an energy-dispersive X-ray spectrometer, as well as X-ray powder diffraction, X-ray fluorescence, and inductively coupled plasma mass spectrometry. The Yili coal is of high volatile C/B bituminous rank (0.51–0.59% vitrinite reflectance) and has a medium sulfur content (1.32% on average). Fusinite and semifusinite generally dominate the maceral assemblage, which exhibits forms suggesting fire-driven formation of those Macerals together with forms suggesting degradation of wood followed by burning. The Yili coals are characterized by high concentrations of U (up to 7207 μg/g), Se (up to 253 μg/g), Mo (1248 μg/g), and Re (up to 34 μg/g), as well as As (up to 234 μg/g) and Hg (up to 3858 ng/g). Relative to the upper continental crust, the rare earth elements (REEs) in the coals are characterized by heavy or/and medium REE enrichment. The minerals in the Yili coals are mainly quartz, kaolinite, illite and illite/smectite, as well as, to a lesser extent, K-feldspar, chlorite, pyrite, and trace amounts of calcite, dolomite, amphibole, millerite, chalcopyrite, cattierite, siegenite, ferroselite, krutaite, eskebornite, pitchblende, coffinite, silicorhabdophane, and zircon. The enrichment and modes of occurrence of the trace elements, and also of the minerals in the coal, are attributed to derivation from a sediment source region of felsic and intermediate petrological composition, and to two different later-stage solutions (a U–Se–Mo–Re rich infiltrational and a Hg–As-rich exfiltrational volcanogenic solution). The main elements with high enrichment factors, U, Se, As, and Hg, overall exhibit a mixed organic–inorganic affinity. The uranium minerals, pitchblende and coffinite, occur as cavity-fillings in structured Inertinite Macerals. Selenium, As, and Hg in high-pyrite samples mainly show a sulfide affinity.
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organic petrology geochemistry gas content and gas composition of middle pennsylvanian age coal beds in the eastern interior illinois basin implications for cbm development and carbon sequestration
International Journal of Coal Geology, 2014Co-Authors: Sarah M Mardon, James C. Hower, Cortland F. Eble, Katherine Takacs, Maria Mastalerz, Marc R BustinAbstract:Abstract Fifty four samples of coal and organic-rich roof shale strata were collected as part of a coal bed methane exploration program. Following canister desorption to document gas contents, the samples were analyzed by geochemical and petrographic methods. Coal samples were found to have moderate ash yields (avg. 13.5%, dry basis), and high total sulfur contents (avg. 4.3%, dry basis). The average gas content was 1.91 m3/ton. Petrographically, the coals were dominated by vitrinite Macerals (avg. 81.6%, mmf), especially telovitrinite. By comparison, liptinite (avg. 7.1%, mmf) and Inertinite Macerals (avg. 11.3%, mmf), were minor in occurrence. Coal samples ranged from high volatile C to high volatile A bituminous in rank (avg. Ro maximum, 0.76%). Shale samples had higher ash yields (avg. 76.1, dry basis), though total sulfur contents were comparable to the coal samples (avg. 4.2%, dry basis). Gas contents were lower than the corresponding coal samples (avg. 0.65 m3/ton). Petrographically, the shale samples contained decreased amounts of vitrinite (avg. 25.6%, mmf), and higher amounts of liptinite (avg. 45.4%, mmf) and Inertinite (avg. 29.0%, mmf) Macerals, relative to the coal samples. Gas obtained from coal and shale beds in the Illinois Basin was relatively pure (high CH4 content). Limited data also indicated that Illinois Basin coals have the ability to adsorb fairly significant amounts of CO2. This suggests that CO2 injection to enhance methane production (ECBM), and/or to sequester CO2 may have some potential. Mineralization in the coals could negatively impact CBM production, but it was found that the majority of the mineralization was present in the roof strata.
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a critical re examination of the petrology of the no 5 block coal in eastern kentucky with special attention to the origin of Inertinite Macerals in the splint lithotypes
International Journal of Coal Geology, 2012Co-Authors: Allison R. Richardson, James C. Hower, Cortland F. Eble, Jennifer M K OkeefeAbstract:Abstract The Pennsylvanian No. 5 Block coal bed in eastern Kentucky is one of several coals considered to be among the splint coals of the Central Appalachians. The coals are generally noted for their Inertinite-rich dull lithotypes. Petrographic aspects of the lithologies reveal both fire-derived and degradation-derived Inertinites in the assemblages. Fire is not an exclusive contributor to the origin to Inertinite Macerals; there are many other biological factors, such as the actions and interactions of fungi, bacteria, and insects, which must be considered in the alteration of plant materials to form Inertinite Macerals. Fungi physically and chemically alter plant tissues to form Macerals with a distinct morphology and chemistry different than those formed from fire and other abiological processes. Insects, as secondary sources of wood degradation within a mire, are responsible for physical, such as boreholes from wood-consuming insects, and chemical alteration of plants. Degradation observed in macrinite may be boreholes from wood-consuming insects such as mites. Some Inertinite Macerals, in particular, macrinite, may be the result of inert fecal pellet conglomerates preserved in the mire. Overall, Macerals of the same name can form from multiple and complex biological and abiological processes.
Jennifer M K Okeefe - One of the best experts on this subject based on the ideXlab platform.
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palynology organic petrology and geochemistry of the bell coal bed in western kentucky eastern interior illinois basin usa
International Journal of Coal Geology, 2019Co-Authors: Cortland F. Eble, James C. Hower, Stephen F Greb, David A Williams, Jennifer M K OkeefeAbstract:Abstract The Bell coal bed is one of the stratigraphically oldest coals (Atokan, Duckmantian) in the Illinois Basin that has been commercially mined and occurs near the Morrowan-Atokan boundary, which was a time of significant lithologic change in the basin. The Bell coal occurs as a series of discontinuous pods, in contrast to younger (Asturian) coals in the basin that are thicker and more extensive in occurrence. Thirty-two samples of coal and carbonaceous shale, collected from surface mine, outcrop, and drill core locations were analyzed geochemically, petrographically and palynologically to ascertain the origin of the Bell coal bed in western Kentucky. The Bell coal exhibits a great deal of variability in thickness and composition, both temporally and spatially. Based on ash yields, the Bell coal consists of intercalated layers of coal (≤25% ash), impure coal (>25 to 80%, mmf), with telovitrinite occurring more frequently than detrovitrinite and gelovitrinite. Certain layers, however, contain elevated amounts of liptinite and Inertinite. Among the Inertinite Macerals, examples of both fire (e.g., fusinite) and degradation (e.g., macrinite) origin are evident. Samples with elevated amounts of Inertinite are commonly, though not exclusively, high in ash, indicating that some of the Inertinite may be of allochthonous origin. Palynologically, the Bell coal is dominated by arborescent lycopod spores (avg. >70%), occurring primarily as Lycospora, with some samples containing increased proportions of spores and pollen from other Pennsylvanian plant groups. Samples with more heterogenous palynofloras commonly have elevated ash yields, indicating that some portion of the assemblages may be also of allochthonous origin. Collectively, the Bell coal is interpreted to have formed from a series of small, disconnected paleomires that were planar and topogenous with paleotopography having an influence on peat development. A planar, topogenous origin helps to explain the highly variable ash yields and sulfur contents. Accumulating peat, principally from arborescent lycopod source material, was mainly well-preserved, but punctuated with intervals marked by sediment influx, the development of more heterogeneous palynofloras and degradation and oxidation of the surficial peat by both biologic (decay) and abiotic (fire) processes.
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mississippian serpukhovian chesterian stage coals from the fluorspar district crittenden and caldwell counties kentucky petrological and palynological compositions and their indications for peat producing ecosystems
International Journal of Coal Geology, 2017Co-Authors: James C. Hower, Jennifer M K Okeefe, Cortland F. EbleAbstract:Abstract Serpukhovian Stage (Chesterian Stage in North American nomenclature) coals in western Kentucky are among the few occurrences of Mississippian coals in eastern North America. Thus, they provide a rare view of early Carboniferous peat-producing ecosystems. Petrographically, the coals are dominated by telovitrinites. Among the Inertinite Macerals, coprolitic macrinite provides evidence of arthropods fungal-degraded wood. Cutinite has an association with epiphyllous fungus. Owing to the relatively high spore contributions from arborescent Lycopsids, the coals bear a palynologic resemblance to the Pennsylvanian Langsettian through Asturian (Westphalian) coals preserved in the nearby Western Kentucky coalfield. The maceral assemblages, however, show a greater similarity to the Upper Pennsylvanian (Stephanian) coals in western Kentucky. With 66–67% total vitrinite and about 29% total Inertinite (dominated by fusinite + semifusinite) (both as volume percent, mineral-fee basis), the Mississippian coals have significantly lower vitrinite percentages than the Westphalian coals. The petrographic similarity is not paralleled by a floristic similarity as the Stephanian flora was marked by the absence of arborescent Lycopsids. Overall, the amount of Inertinites and the degradation suggested by a number of the Inertinite forms suggests that, not unexpectedly decay and degradation was an important contributor to the Mississippian coals. As with any coals, the Mississippian coals represent a story of preservation more than that of degradation and destruction, with degraded and poorly-preserved fusinite and semifusinite, coprolitic macrinite, and remnants of fungi being the ghosts of the destruction of the biomass.
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geochemical and mineralogical evidence for a coal hosted uranium deposit in the yili basin xinjiang northwestern china
Ore Geology Reviews, 2015Co-Authors: Shifeng Dai, Colin R. Ward, James C. Hower, David French, Jianye Yang, Huidong Liu, Trent M Garrison, Jennifer M K OkeefeAbstract:Abstract The petrological, geochemical, and mineralogical compositions of the coal-hosted Jurassic uranium ore deposit in the Yili Basin of Xinjiang province, northwestern China, were investigated using optical microscopy and field emission-scanning electron microscopy in conjunction with an energy-dispersive X-ray spectrometer, as well as X-ray powder diffraction, X-ray fluorescence, and inductively coupled plasma mass spectrometry. The Yili coal is of high volatile C/B bituminous rank (0.51–0.59% vitrinite reflectance) and has a medium sulfur content (1.32% on average). Fusinite and semifusinite generally dominate the maceral assemblage, which exhibits forms suggesting fire-driven formation of those Macerals together with forms suggesting degradation of wood followed by burning. The Yili coals are characterized by high concentrations of U (up to 7207 μg/g), Se (up to 253 μg/g), Mo (1248 μg/g), and Re (up to 34 μg/g), as well as As (up to 234 μg/g) and Hg (up to 3858 ng/g). Relative to the upper continental crust, the rare earth elements (REEs) in the coals are characterized by heavy or/and medium REE enrichment. The minerals in the Yili coals are mainly quartz, kaolinite, illite and illite/smectite, as well as, to a lesser extent, K-feldspar, chlorite, pyrite, and trace amounts of calcite, dolomite, amphibole, millerite, chalcopyrite, cattierite, siegenite, ferroselite, krutaite, eskebornite, pitchblende, coffinite, silicorhabdophane, and zircon. The enrichment and modes of occurrence of the trace elements, and also of the minerals in the coal, are attributed to derivation from a sediment source region of felsic and intermediate petrological composition, and to two different later-stage solutions (a U–Se–Mo–Re rich infiltrational and a Hg–As-rich exfiltrational volcanogenic solution). The main elements with high enrichment factors, U, Se, As, and Hg, overall exhibit a mixed organic–inorganic affinity. The uranium minerals, pitchblende and coffinite, occur as cavity-fillings in structured Inertinite Macerals. Selenium, As, and Hg in high-pyrite samples mainly show a sulfide affinity.
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a critical re examination of the petrology of the no 5 block coal in eastern kentucky with special attention to the origin of Inertinite Macerals in the splint lithotypes
International Journal of Coal Geology, 2012Co-Authors: Allison R. Richardson, James C. Hower, Cortland F. Eble, Jennifer M K OkeefeAbstract:Abstract The Pennsylvanian No. 5 Block coal bed in eastern Kentucky is one of several coals considered to be among the splint coals of the Central Appalachians. The coals are generally noted for their Inertinite-rich dull lithotypes. Petrographic aspects of the lithologies reveal both fire-derived and degradation-derived Inertinites in the assemblages. Fire is not an exclusive contributor to the origin to Inertinite Macerals; there are many other biological factors, such as the actions and interactions of fungi, bacteria, and insects, which must be considered in the alteration of plant materials to form Inertinite Macerals. Fungi physically and chemically alter plant tissues to form Macerals with a distinct morphology and chemistry different than those formed from fire and other abiological processes. Insects, as secondary sources of wood degradation within a mire, are responsible for physical, such as boreholes from wood-consuming insects, and chemical alteration of plants. Degradation observed in macrinite may be boreholes from wood-consuming insects such as mites. Some Inertinite Macerals, in particular, macrinite, may be the result of inert fecal pellet conglomerates preserved in the mire. Overall, Macerals of the same name can form from multiple and complex biological and abiological processes.
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petrology mineralogy and geochemistry of the ge rich coal from the wulantuga ge ore deposit inner mongolia china new data and genetic implications
International Journal of Coal Geology, 2012Co-Authors: Shifeng Dai, Colin R. Ward, James C. Hower, Jennifer M K Okeefe, Huidong Liu, Xibo Wang, Vladimir V Seredin, Wenhui Huang, Weifeng Xue, Lixin ZhaoAbstract:Abstract The Early Cretaceous Wulantuga high-Ge coal deposit in Inner Mongolia is one of the major coal-hosted Ge deposits in China. This paper reports new data on the petrological, mineralogical, and geochemical compositions of 13 bench samples of the high-Ge No. 6 coal from the Wulantuga deposit, and provides new insight into the origin and modes of occurrence of the minerals and elements present. The No. 6 Coal has a low rank (Ro,max = 0.45%) and is a low-ash coal (8.77%). The total content of Inertinite (52.5 vol.% on average) in most coal benches is higher than that of huminite (46.8 vol.% on average). The dominant huminite maceral is textinite (averages 43.9%), and the dominant Inertinite Macerals are mainly fusinite (averages 33%) and semifusinite (12.5%), along with trace portions of intertodetrinite, secretinite, funginite, and macrinite. Fungus, seen as the maceral funginite, played a role in the development of degraded maceral forms in the Wulantuga coals. Funginite is present in samples examined in this study, but is not easily extracted during palynological studies; recovered fungal taxa are saprophytes, indicating woody decomposition prior to incorporation in the mire. Palynology revealed a sparse flora that is consistent with the early Cretaceous age. Minerals in the coal include quartz, kaolinite, illite (and/or illite/smectite), gypsum, pyrite, and traces of rutile and anatase. A varying proportion of bassanite was observed in the low-temperature ashes (LTAs). Bassanite in the LTAs was derived both from the dehydration of gypsum in the raw coals and from the interaction between organically-associated Ca and S during the low-temperature ashing. In addition to a proportion of detrital quartz, fine-grained and cell-filling quartz of authigenic origin is also present. Pyrite is of syngenetic origin and derived from sulfate-rich hydrothermal fluids. Compared to common Chinese and world low-rank coals, the No. 6 Coal is enriched in Be (25.7 μg/g), F (336 μg/g), Ge (274 μg/g), As (499 μg/g), Sb (240 μg/g), Cs (5.29 μg/g), W (115 μg/g), Hg (3.165 μg/g), and Tl (3.15 μg/g). Germanium in the coal is organically associated, and its enrichment is attributed to hydrothermal fluids from the adjacent granitoids. Beryllium is probably associated with Ca- and Mn-bearing carbonate minerals and to a lesser extent with clay minerals, rather than with organic matter. Fluorine largely occurs in clay minerals (kaolinite and illite). The elevated concentrations of Tl, Hg, As, and Sb are mainly distributed in pyrite and were derived from the same hydrothermal source. The high W in the coal occurs in both the organic matter and the authigenic quartz. Illite is the major carrier of Cs in the coal. The accumulation of rare earth elements (REE) in the coals had a polygenetic and multistage nature, including two syngenetic stages (early hydrothermal and terrigenous) and one diagenetic (late hydrothermal) stage. The REE distribution patterns of the early hydrothermal and terrigenous stages were characterized by the enrichment of medium REE (M-type REE) and light REE (L-type REE), respectively. A H-type REE distribution pattern (HREE enrichment) occurred in the late diagenetic hydrothermal stage. The high-Ge Wulantuga coals are also abnormally enriched in precious metals. Gold, Pt, and Pd in the coals, calculated from their concentrations in the LTAs, are 3.5–25.8,
Cortland F. Eble - One of the best experts on this subject based on the ideXlab platform.
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palynology organic petrology and geochemistry of the bell coal bed in western kentucky eastern interior illinois basin usa
International Journal of Coal Geology, 2019Co-Authors: Cortland F. Eble, James C. Hower, Stephen F Greb, David A Williams, Jennifer M K OkeefeAbstract:Abstract The Bell coal bed is one of the stratigraphically oldest coals (Atokan, Duckmantian) in the Illinois Basin that has been commercially mined and occurs near the Morrowan-Atokan boundary, which was a time of significant lithologic change in the basin. The Bell coal occurs as a series of discontinuous pods, in contrast to younger (Asturian) coals in the basin that are thicker and more extensive in occurrence. Thirty-two samples of coal and carbonaceous shale, collected from surface mine, outcrop, and drill core locations were analyzed geochemically, petrographically and palynologically to ascertain the origin of the Bell coal bed in western Kentucky. The Bell coal exhibits a great deal of variability in thickness and composition, both temporally and spatially. Based on ash yields, the Bell coal consists of intercalated layers of coal (≤25% ash), impure coal (>25 to 80%, mmf), with telovitrinite occurring more frequently than detrovitrinite and gelovitrinite. Certain layers, however, contain elevated amounts of liptinite and Inertinite. Among the Inertinite Macerals, examples of both fire (e.g., fusinite) and degradation (e.g., macrinite) origin are evident. Samples with elevated amounts of Inertinite are commonly, though not exclusively, high in ash, indicating that some of the Inertinite may be of allochthonous origin. Palynologically, the Bell coal is dominated by arborescent lycopod spores (avg. >70%), occurring primarily as Lycospora, with some samples containing increased proportions of spores and pollen from other Pennsylvanian plant groups. Samples with more heterogenous palynofloras commonly have elevated ash yields, indicating that some portion of the assemblages may be also of allochthonous origin. Collectively, the Bell coal is interpreted to have formed from a series of small, disconnected paleomires that were planar and topogenous with paleotopography having an influence on peat development. A planar, topogenous origin helps to explain the highly variable ash yields and sulfur contents. Accumulating peat, principally from arborescent lycopod source material, was mainly well-preserved, but punctuated with intervals marked by sediment influx, the development of more heterogeneous palynofloras and degradation and oxidation of the surficial peat by both biologic (decay) and abiotic (fire) processes.
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mississippian serpukhovian chesterian stage coals from the fluorspar district crittenden and caldwell counties kentucky petrological and palynological compositions and their indications for peat producing ecosystems
International Journal of Coal Geology, 2017Co-Authors: James C. Hower, Jennifer M K Okeefe, Cortland F. EbleAbstract:Abstract Serpukhovian Stage (Chesterian Stage in North American nomenclature) coals in western Kentucky are among the few occurrences of Mississippian coals in eastern North America. Thus, they provide a rare view of early Carboniferous peat-producing ecosystems. Petrographically, the coals are dominated by telovitrinites. Among the Inertinite Macerals, coprolitic macrinite provides evidence of arthropods fungal-degraded wood. Cutinite has an association with epiphyllous fungus. Owing to the relatively high spore contributions from arborescent Lycopsids, the coals bear a palynologic resemblance to the Pennsylvanian Langsettian through Asturian (Westphalian) coals preserved in the nearby Western Kentucky coalfield. The maceral assemblages, however, show a greater similarity to the Upper Pennsylvanian (Stephanian) coals in western Kentucky. With 66–67% total vitrinite and about 29% total Inertinite (dominated by fusinite + semifusinite) (both as volume percent, mineral-fee basis), the Mississippian coals have significantly lower vitrinite percentages than the Westphalian coals. The petrographic similarity is not paralleled by a floristic similarity as the Stephanian flora was marked by the absence of arborescent Lycopsids. Overall, the amount of Inertinites and the degradation suggested by a number of the Inertinite forms suggests that, not unexpectedly decay and degradation was an important contributor to the Mississippian coals. As with any coals, the Mississippian coals represent a story of preservation more than that of degradation and destruction, with degraded and poorly-preserved fusinite and semifusinite, coprolitic macrinite, and remnants of fungi being the ghosts of the destruction of the biomass.
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organic petrology geochemistry gas content and gas composition of middle pennsylvanian age coal beds in the eastern interior illinois basin implications for cbm development and carbon sequestration
International Journal of Coal Geology, 2014Co-Authors: Sarah M Mardon, James C. Hower, Cortland F. Eble, Katherine Takacs, Maria Mastalerz, Marc R BustinAbstract:Abstract Fifty four samples of coal and organic-rich roof shale strata were collected as part of a coal bed methane exploration program. Following canister desorption to document gas contents, the samples were analyzed by geochemical and petrographic methods. Coal samples were found to have moderate ash yields (avg. 13.5%, dry basis), and high total sulfur contents (avg. 4.3%, dry basis). The average gas content was 1.91 m3/ton. Petrographically, the coals were dominated by vitrinite Macerals (avg. 81.6%, mmf), especially telovitrinite. By comparison, liptinite (avg. 7.1%, mmf) and Inertinite Macerals (avg. 11.3%, mmf), were minor in occurrence. Coal samples ranged from high volatile C to high volatile A bituminous in rank (avg. Ro maximum, 0.76%). Shale samples had higher ash yields (avg. 76.1, dry basis), though total sulfur contents were comparable to the coal samples (avg. 4.2%, dry basis). Gas contents were lower than the corresponding coal samples (avg. 0.65 m3/ton). Petrographically, the shale samples contained decreased amounts of vitrinite (avg. 25.6%, mmf), and higher amounts of liptinite (avg. 45.4%, mmf) and Inertinite (avg. 29.0%, mmf) Macerals, relative to the coal samples. Gas obtained from coal and shale beds in the Illinois Basin was relatively pure (high CH4 content). Limited data also indicated that Illinois Basin coals have the ability to adsorb fairly significant amounts of CO2. This suggests that CO2 injection to enhance methane production (ECBM), and/or to sequester CO2 may have some potential. Mineralization in the coals could negatively impact CBM production, but it was found that the majority of the mineralization was present in the roof strata.
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a critical re examination of the petrology of the no 5 block coal in eastern kentucky with special attention to the origin of Inertinite Macerals in the splint lithotypes
International Journal of Coal Geology, 2012Co-Authors: Allison R. Richardson, James C. Hower, Cortland F. Eble, Jennifer M K OkeefeAbstract:Abstract The Pennsylvanian No. 5 Block coal bed in eastern Kentucky is one of several coals considered to be among the splint coals of the Central Appalachians. The coals are generally noted for their Inertinite-rich dull lithotypes. Petrographic aspects of the lithologies reveal both fire-derived and degradation-derived Inertinites in the assemblages. Fire is not an exclusive contributor to the origin to Inertinite Macerals; there are many other biological factors, such as the actions and interactions of fungi, bacteria, and insects, which must be considered in the alteration of plant materials to form Inertinite Macerals. Fungi physically and chemically alter plant tissues to form Macerals with a distinct morphology and chemistry different than those formed from fire and other abiological processes. Insects, as secondary sources of wood degradation within a mire, are responsible for physical, such as boreholes from wood-consuming insects, and chemical alteration of plants. Degradation observed in macrinite may be boreholes from wood-consuming insects such as mites. Some Inertinite Macerals, in particular, macrinite, may be the result of inert fecal pellet conglomerates preserved in the mire. Overall, Macerals of the same name can form from multiple and complex biological and abiological processes.
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notes on the origin of Inertinite Macerals in coal evidence for fungal and arthropod transformations of degraded Macerals
International Journal of Coal Geology, 2011Co-Authors: James C. Hower, Cortland F. Eble, Allison R. Richardson, Jennifer M K Okeefe, Anne Raymond, Bruno Valentim, Thomas J Volk, Anne B Satterwhite, Rachel Hatch, J.d. StuckerAbstract:The role of fungus in the formation of coal Macerals, both as a primary contributor in the form of a fungus fossil/maceral funginite, and in their role in degrading wood, thus producing degraded maceral forms, has been established. Fungus, in the course of breaking down the lignin and cellulose in wood, make the wood more digestible for grazers, such as arthropods. In turn, the remnants of the digested wood and anything else eaten but not completely digested are excreted and can be preserved intact; eaten by other fauna with a repeat of the cycle; or colonized by bacteria and/or coprophilous fungi with or without subsequent preservation. Ultimately, the coprolites can be preserved as a form of macrinite.
Colin R. Ward - One of the best experts on this subject based on the ideXlab platform.
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coal derived unburned carbons in fly ash a review
International Journal of Coal Geology, 2017Co-Authors: John G Groppo, Colin R. Ward, Uschi M Graham, Irena Kostova, Mercedes M MarotovalerAbstract:Abstract Unburned carbon (UC) in fly ash indicates inefficiency in combustion and may be an impediment to the beneficial use of fly ash or ash products in a variety of applications. The characteristics of the coal-derived UC are a function of the rank and type of the coal, as well as the size of the feed coal and the combustion conditions. At any coal rank, Inertinite Macerals are inherently more difficult to combust than the associated vitrinite, and some will have a tendency to appear in the fly ash more or less unchanged from their appearance in the feed coal. The nature of UCs resulting from vitrinite is dependent upon the coal rank. Low-rank huminite/vitrinite will tend to form an isotropic char; bituminous vitrinite will appear as isotropic and anisotropic cokes; and anthracite vitrinite, naturally anisotropic, is observed as partially combusted vitrinite fragments in the ash. The absorption of air entraining agents by UCs limits the use of high-UC fly ashes as a Portland cement substitute, with both standards organizations and regulatory bodies imposing limits on the acceptable UC concentrations. UC in fly ash can be used to adsorb organic compounds (such as phenols, dyes, herbicides, polychlorinated biphenyls, and petroleum constituents) and to capture trace elements (particularly Hg) from flue gas. UCs can also be used as sources of activated carbons, manufacture of graphite, and cokes in the metallurgical industry, as well as a source of carbon to feed back into the boiler. Beneficiation of fly ash to segregate relatively UC-free or UC-rich splits for beneficial re-use can be done by size classification, electrostatic separation, and froth flotation, as well as density separation, acid digestion, and incipient fluidization. Thermal processing may also be used to burn off the UC, leaving a relatively UC-free fly ash as the product.
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geochemical and mineralogical evidence for a coal hosted uranium deposit in the yili basin xinjiang northwestern china
Ore Geology Reviews, 2015Co-Authors: Shifeng Dai, Colin R. Ward, James C. Hower, David French, Jianye Yang, Huidong Liu, Trent M Garrison, Jennifer M K OkeefeAbstract:Abstract The petrological, geochemical, and mineralogical compositions of the coal-hosted Jurassic uranium ore deposit in the Yili Basin of Xinjiang province, northwestern China, were investigated using optical microscopy and field emission-scanning electron microscopy in conjunction with an energy-dispersive X-ray spectrometer, as well as X-ray powder diffraction, X-ray fluorescence, and inductively coupled plasma mass spectrometry. The Yili coal is of high volatile C/B bituminous rank (0.51–0.59% vitrinite reflectance) and has a medium sulfur content (1.32% on average). Fusinite and semifusinite generally dominate the maceral assemblage, which exhibits forms suggesting fire-driven formation of those Macerals together with forms suggesting degradation of wood followed by burning. The Yili coals are characterized by high concentrations of U (up to 7207 μg/g), Se (up to 253 μg/g), Mo (1248 μg/g), and Re (up to 34 μg/g), as well as As (up to 234 μg/g) and Hg (up to 3858 ng/g). Relative to the upper continental crust, the rare earth elements (REEs) in the coals are characterized by heavy or/and medium REE enrichment. The minerals in the Yili coals are mainly quartz, kaolinite, illite and illite/smectite, as well as, to a lesser extent, K-feldspar, chlorite, pyrite, and trace amounts of calcite, dolomite, amphibole, millerite, chalcopyrite, cattierite, siegenite, ferroselite, krutaite, eskebornite, pitchblende, coffinite, silicorhabdophane, and zircon. The enrichment and modes of occurrence of the trace elements, and also of the minerals in the coal, are attributed to derivation from a sediment source region of felsic and intermediate petrological composition, and to two different later-stage solutions (a U–Se–Mo–Re rich infiltrational and a Hg–As-rich exfiltrational volcanogenic solution). The main elements with high enrichment factors, U, Se, As, and Hg, overall exhibit a mixed organic–inorganic affinity. The uranium minerals, pitchblende and coffinite, occur as cavity-fillings in structured Inertinite Macerals. Selenium, As, and Hg in high-pyrite samples mainly show a sulfide affinity.
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maceral characteristics and vitrinite reflectance variation of the high rank coals south walker creek bowen basin australia
Indonesian Journal on Geoscience, 2013Co-Authors: Asep Kurnia Permana, Colin R. Ward, Lila W. GurbaAbstract:DOI: 10.17014/ijog.v8i2.156 The Permian coals of the South Walker Creek area, with a vitrinite reflectance (Rvmax) of 1.7 to 1.95% (low-volatile bituminous to semi-anthracite), are one of the highest rank coals currently mined in the Bowen Basin for the pulverized coal injection (PCI) market. Studies of petrology of this coal seam have identified that the maceral composition of the coals are dominated by Inertinite with lesser vitrinite, and only minor amounts of liptinite. Clay minerals, quartz, and carbonates can be seen under the optical microscope. The mineral matter occurs in association with vitrinite and Inertinite Macerals as syngenetic and epigenetic mineral phases. The irregular pattern of the vitrinite reflectance profile from the top to the bottom of the seam may represent a response in the organic matter to an uneven heat distribution from such hydrothermal influence. Examination of the maceral and vitrinite reflectance characteristics suggest that the mineralogical variation within the coal seam at South Walker Creek may have been controlled by various geological processes, including sediment input into the peat swamp during deposition, mineralogical changes associated with the rank advance process or metamorphism, and/or hydrothermal effects due to post depositional fluid migration through the coal seam.
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mineralogy and leaching characteristics of beneficiated coal products from santa catarina brazil
International Journal of Coal Geology, 2012Co-Authors: Marcos L S Oliveira, Colin R. Ward, James C. Hower, David French, Xavier Querol, Luis F O SilvaAbstract:Abstract Petrographic, mineralogical and geochemical studies have been carried out on beneficiated coal products from mines and preparation plants in the Santa Catarina Basin, southern Brazil, to investigate the range of characteristics exhibited by the materials and the potential impact of their stockpiling and storage on the environment. The coals contain varying proportions of vitrinite and Inertinite Macerals, and have vitrinite reflectance values ranging from 0.44 to 1.38%. With the exception of one material blended with peat from an external source, they have relatively high percentages of ash (30–58%) and mineral matter (36–66%). The mineral matter consists mainly of clay minerals (kaolinite, illite and illite/smectite), together with 15–25% quartz, up to 10% feldspar, up to 5% calcite and/or dolomite and up to 5% pyrite, and around 1% anatase and/or rutile. Bassanite is also present in low-temperature ash derived from the coals, mainly derived from interaction of Ca and S associated with the organic matter. Jarosite is formed by pyrite oxidation in coals that have been exposed in stockpiles for extended periods. Most of the trace elements in most of the coals have higher concentrations than average values for world coals generally, probably due to the relatively high mineral matter content. A lower-ash product representing a blend of coal and peat has similar to lower concentrations of most elements, but higher concentrations of B, Ba, Be, Cd, Ge and Mn, which may be associated with the peat component. Interaction of relatively fresh coals with water in laboratory tests produces leachates with near-neutral to mildly acid pH values, but leaching of oxidized, jarosite-bearing coal produces a strongly acid leachate, with higher concentrations of Cd, Co, Cu, Ni and Zn. Leachates derived from coals in which the pyrite has been oxidized during storage would thus be expected to have a more adverse environmental impact than leachates derived from coals in which such oxidation has not had an opportunity to develop.
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petrology mineralogy and geochemistry of the ge rich coal from the wulantuga ge ore deposit inner mongolia china new data and genetic implications
International Journal of Coal Geology, 2012Co-Authors: Shifeng Dai, Colin R. Ward, James C. Hower, Jennifer M K Okeefe, Huidong Liu, Xibo Wang, Vladimir V Seredin, Wenhui Huang, Weifeng Xue, Lixin ZhaoAbstract:Abstract The Early Cretaceous Wulantuga high-Ge coal deposit in Inner Mongolia is one of the major coal-hosted Ge deposits in China. This paper reports new data on the petrological, mineralogical, and geochemical compositions of 13 bench samples of the high-Ge No. 6 coal from the Wulantuga deposit, and provides new insight into the origin and modes of occurrence of the minerals and elements present. The No. 6 Coal has a low rank (Ro,max = 0.45%) and is a low-ash coal (8.77%). The total content of Inertinite (52.5 vol.% on average) in most coal benches is higher than that of huminite (46.8 vol.% on average). The dominant huminite maceral is textinite (averages 43.9%), and the dominant Inertinite Macerals are mainly fusinite (averages 33%) and semifusinite (12.5%), along with trace portions of intertodetrinite, secretinite, funginite, and macrinite. Fungus, seen as the maceral funginite, played a role in the development of degraded maceral forms in the Wulantuga coals. Funginite is present in samples examined in this study, but is not easily extracted during palynological studies; recovered fungal taxa are saprophytes, indicating woody decomposition prior to incorporation in the mire. Palynology revealed a sparse flora that is consistent with the early Cretaceous age. Minerals in the coal include quartz, kaolinite, illite (and/or illite/smectite), gypsum, pyrite, and traces of rutile and anatase. A varying proportion of bassanite was observed in the low-temperature ashes (LTAs). Bassanite in the LTAs was derived both from the dehydration of gypsum in the raw coals and from the interaction between organically-associated Ca and S during the low-temperature ashing. In addition to a proportion of detrital quartz, fine-grained and cell-filling quartz of authigenic origin is also present. Pyrite is of syngenetic origin and derived from sulfate-rich hydrothermal fluids. Compared to common Chinese and world low-rank coals, the No. 6 Coal is enriched in Be (25.7 μg/g), F (336 μg/g), Ge (274 μg/g), As (499 μg/g), Sb (240 μg/g), Cs (5.29 μg/g), W (115 μg/g), Hg (3.165 μg/g), and Tl (3.15 μg/g). Germanium in the coal is organically associated, and its enrichment is attributed to hydrothermal fluids from the adjacent granitoids. Beryllium is probably associated with Ca- and Mn-bearing carbonate minerals and to a lesser extent with clay minerals, rather than with organic matter. Fluorine largely occurs in clay minerals (kaolinite and illite). The elevated concentrations of Tl, Hg, As, and Sb are mainly distributed in pyrite and were derived from the same hydrothermal source. The high W in the coal occurs in both the organic matter and the authigenic quartz. Illite is the major carrier of Cs in the coal. The accumulation of rare earth elements (REE) in the coals had a polygenetic and multistage nature, including two syngenetic stages (early hydrothermal and terrigenous) and one diagenetic (late hydrothermal) stage. The REE distribution patterns of the early hydrothermal and terrigenous stages were characterized by the enrichment of medium REE (M-type REE) and light REE (L-type REE), respectively. A H-type REE distribution pattern (HREE enrichment) occurred in the late diagenetic hydrothermal stage. The high-Ge Wulantuga coals are also abnormally enriched in precious metals. Gold, Pt, and Pd in the coals, calculated from their concentrations in the LTAs, are 3.5–25.8,
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maceral characteristics and vitrinite reflectance variation of the high rank coals south walker creek bowen basin australia
Indonesian Journal on Geoscience, 2013Co-Authors: Asep Kurnia Permana, Colin R. Ward, Lila W. GurbaAbstract:DOI: 10.17014/ijog.v8i2.156 The Permian coals of the South Walker Creek area, with a vitrinite reflectance (Rvmax) of 1.7 to 1.95% (low-volatile bituminous to semi-anthracite), are one of the highest rank coals currently mined in the Bowen Basin for the pulverized coal injection (PCI) market. Studies of petrology of this coal seam have identified that the maceral composition of the coals are dominated by Inertinite with lesser vitrinite, and only minor amounts of liptinite. Clay minerals, quartz, and carbonates can be seen under the optical microscope. The mineral matter occurs in association with vitrinite and Inertinite Macerals as syngenetic and epigenetic mineral phases. The irregular pattern of the vitrinite reflectance profile from the top to the bottom of the seam may represent a response in the organic matter to an uneven heat distribution from such hydrothermal influence. Examination of the maceral and vitrinite reflectance characteristics suggest that the mineralogical variation within the coal seam at South Walker Creek may have been controlled by various geological processes, including sediment input into the peat swamp during deposition, mineralogical changes associated with the rank advance process or metamorphism, and/or hydrothermal effects due to post depositional fluid migration through the coal seam.
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elemental composition of coal Macerals in relation to vitrinite reflectance gunnedah basin australia as determined by electron microprobe analysis
International Journal of Coal Geology, 2000Co-Authors: Lila W. Gurba, Colin R. WardAbstract:Abstract The elemental composition of Macerals in high-volatile bituminous coals from the Gunnedah Basin, New South Wales, Australia, has been analysed by light-element electron microprobe techniques. The results have been evaluated in relation to maximum vitrinite reflectance trends in vertical section, including the effects of marine influence and igneous intrusions on the coal-bearing sequence. Mean maximum vitrinite (telocollinite and desmocollinite) reflectance for the analysed samples ranges from 0.63% to 0.99%, and to 2.2% for coal affected by igneous intrusions. The carbon content of the vitrinite, as determined by electron microprobe, ranges from 79.74% to 86.07%, and up to 89.06% for the heat-affected coal studied. A simple relationship cannot be established between the reflectance of the vitrinite and its carbon content over this range of coal samples. Vitrinite in marine influenced coals (with suppressed reflectance) appears to have a slightly higher carbon content than vitrinite in isorank coals without marine influence. The increase in carbon may be due to incorporation of carbon and sulphur–rich lipoid material into the vitrinite component. Notwithstanding these differences, the carbon content of vitrinite (telocollinite) seems to be affected only slightly by the depositional changes that cause suppression of vitrinite reflectance in marine-influenced coals. Telocollinite carbon content may therefore be a useful alternative to vitrinite reflectance as a rank indicator in maturation studies. The carbon content of whole-coal samples, determined by ultimate analysis, shows in vertical section a trend intermediate between the carbon of the vitrinite determined by electron microprobe and that of the associated Inertinite Macerals. Whole-coal analysis data in this range depend on the relative proportions of the different Macerals present, as well as the rank of the coal concerned. Coals affected by igneous intrusion show a different relationship between carbon and oxygen of vitrinite (telocollinite), relative to coals where the rank is determined by depth of burial alone. The difference in C–O relationships suggests that the short-term heating associated with intrusions produces chemical changes in Macerals that are not paralleled in more normal rank advance.
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Chemical composition of Macerals in bituminous coals of the Gunnedah Basin, Australia, using electron microprobe analysis techniques
International Journal of Coal Geology, 1999Co-Authors: Colin R. Ward, Lila W. GurbaAbstract:Abstract The chemical composition of the organic matter in the principal Macerals of high-volatile bituminous coals from the Gunnedah Basin, New South Wales (Rvmax of telocollinite between 0.6 and 1.1%) has been evaluated from polished section specimens using an electron microprobe technique. Highest proportions of carbon occur in the Inertinite Macerals, especially fusinite and secretinite (formerly resino-sclerotinite), as well as in sporinite; lowest proportions of carbon occur in the different Macerals of the vitrinite group. Oxygen shows the reverse trend, being most abundant in vitrinite and least abundant in the Inertinite components, whereas sulphur is lowest in the Inertinites and highest in the liptinite (mainly sporinite) present. Evaluations of maceral composition, using the carbon content of telocollinite as a rank indicator, show that carbon is more abundant in both sporinite and semifusinite, relative to vitrinite, in low-rank high-volatile bituminous coals. The difference decreases with increasing rank, and the proportion of carbon in telocollinite becomes essentially the same as that in sporinite and semifusinite at carbon contents of about 89 and 91%, respectively. The carbon content of fusinite and secretinite, on the other hand, does not seem to vary appreciably with rank advance. No significant difference in composition occurs in the rank range studied between the three vitrinite varieties present, desmocollinite, telocollinite and a more highly reflecting telocollinite resembling pseudovitrinite. No evidence was found to indicate a higher hydrogen content, relative to telocollinite, for the vitrinite matrix of desmocollinite.