organic geochemistry of the kolmani river-1 well, upper...

65st Annual Meeting of the ICCP’ 2013, Sosnowiec, Poland

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Organic geochemistry of the Kolmani River-1 Well, Upper Benue Trough, Nigeria: implication on source-rock potential for oil and gas T.A. Adedosu1,2, T.R. Ajayi3, Y. Xiong1, A. Akinlua4, Y. Li1, C. Fang1, Y. Chen1 1 State Key Laboratory of Organic Geochemistry (SKLOG), Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, P. R. China; +86-13416332374; [email protected] 2 Department of Chemistry, Ladoke Akintola University of Technology, PMB 4000, Ogbomoso Nigeria 3 Department of Geology, Obafemi Awolowo University, Ile-Ife, Nigeria 4 Fossil Fuels and Environmental Geochemistry Group, Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria

Integrated geochemical approach of analysis can be a useful tool in hydrocarbon exploration success. Elemental analysis, Rock-Eval pyrolysis, gas chromatography coupled with flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-MS) and Gas Chromatography–Combustion–Isotope Ratio Mass Spectrometer (GC–IRMS) were used to characterize forty ditch-cuttings (731.5 to 2724.9 m), spanning across four Formations from the Kolmani River-1 well, Gongola basin (the upper Benue trough), Nigeria in order to assess its potential source rock and evaluate the source, oxicity, depositional environment and thermal maturity of organic matter contained in the samples. Generally, high %S (> 0.5 wt%), low C/N, TOC/S and TOC/N ratios indicate that samples were derived largely from marine algae deposited under anoxic to sub-oxic condition. The samples contain minimum amount of 0.5 wt% Total Organic Carbon (TOC) contents required to serve as a potential source rock of hydrocarbon. Hydrogen Index (HI) values and plots of HI vs. OI, H/C vs. O/C classify the kerogen as type III/IV capable of generating hydrocarbons. The biomarker distributions in the samples are characterized by dominant medium molecular weight compounds (n-C18 to n-C24), low Pr/Ph ratio (0.32 to 1.34), relatively high phytane/n-C18 ratios (0.35 to 2.52), abundant hopanes, homohopanes, gammacerane and predominant C28, C29 regular and rearranged steranes. The notable presence of 1,2,5-, 1,2,6-, and 1,2,7-trimethylnaphthalenes, as well as 1,2,5,6-, 1,2,5,7-, 1,3,6,7-tetramethylnaphthalenes in the samples indicate angiosperm, gymnosperms and microbial input. The predominance of 9-methylphenanthrene depicts strong presence of marine organic matter, while the occurrence of 1,2,8-trimethylphenanthrene reflects contribution from bacteria, algal or terrestrial materials. The biomarker parameters, predominance of alkyldibenzothiophenes, chrysene/phenanthrene (0.23-3.12), 2-+9-benzo-(a)-anthracene/2-methylchrysene (0.13-6.74) ratios, distribution of polyaromatic hydrocarbons and heterocycles, as well as carbon isotopic distribution of individual alkanes in the samples indicate that the organic matter was derived majorly from phytoplankton, e.g. marine algae and bacterioplankton and deposited under anoxic (Pindiga and Bima) and anoxic to suboxic (Gombe and Yolde) conditions in terrestrial to marine/lacustrine (the Gombe Formation), marine/lacustrine (Pindiga and Yolde) and lacustrine (Bima). However, the presence of oleanenes isomers; olean-12-ene, olean-13(18)-ene and olean-18-ene, low %S (> 0.5 wt%) and high C/N, TOC/S and TOC/N in samples from the upper part of Gombe Formation supports terrestrial plant contribution to the organic

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matter contained in the samples. Various maturity parameters computed from Rock-Eval, biomarkers, polyaromatic- and heterocyclic- hydrocarbons reveal that majority of the samples are immature to low mature except Yolde samples which can be regarded to be in the early oil-window. However, relatively high value of fluoranthene/(fluoranthene + pyrene) ratio (0.86) recorded in K11 (Gombe) with the depth (1344.2 m) might reflect expulsion of hydrocarbons from this source-rock to yet-to-be identified reservoir rock. Also, the Bima rocks at greater depth might be a promising potential source-rock of hydrocarbons.


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A.S. & Co. - SpectraVision 4 - Overview and new developments H. Althoff, H. Behl A.S. & Co. GmbH, Falkweg 48c, 81243 München www.microscope-spectroscopy.com Since 1999 A.S & Co has been established as a reliable partner for scientist working in the field of geological light microscopy. Starting with systems like the Zeiss UMSP or the Leica MPV series and system upgrades, new developments in spectroscopy and imaging have redefined the targets of quantitative measurements for Geologists. DIN/ISO norms for Vitrinite Reflectance still must be covered, but new instruments shall also accelerate the workflow, measure colours or fluorescence shifts and to fulfil the needs of a quality control.

The latest product in the A.S. & Co series is SpectraVision 4. The software platform covers various hardware combinations like photomultipliers, spectrometers and imaging cameras, light sources, lasers and monochromator systems; the workflow can be specified for routine measurements as well as for individual scientific needs. SpectraVision 4 with PMT offer Vitrinite Reflectance as well as fluorescence intensity based on a classical photometer system. The sensor is coupled direct without a fibre to receive the best possible signal quality. An optional cooling circuit improves the signal/noise ratio; combined with a monochromator spectral responses can be recorded. With 64000 gray values the PMT still is the most precise sensor for critical changes in intensity. SpectraVision 4 with cCCD spectrometers offer comparative results to PMT systems, but have the additional benefit to specify spore colours and fluorescence spectral changes according to the CIELab, against defined fluorescence standards or with our certified halogen lamp as a reference, according to Ottenjann. Combining the classical vitrinite analysis with the red green shift detection or the observation of spectral properties gives new criteria in the evaluation of geological strata but also in the classification of Dispersed Organic Matter, at optical resolutions on the limits of light microscopic magnification.

SpectraVision 4 Geo Imaging is a new tool, to accelerate the procedure for Vitrinite Reflectance. Based on principles for modern imaging systems 12-16 BIT video cameras detect the primary image. In the manual version the measurement positions are selected interactive. Focused on special application like steel coal analysis algorithms for grain and pattern recognition automatically select the measurement positions. Its shape and location will be displayed in an mosaic image and the measurement results are shown in a histogram according to the norms. Based on motorised microscopes and special sample mountings in combination with a scanning stage the setup can analyse several samples in one loop.

Spectra Vision 4 offers these different applications individually scaled and integrated in one software platform, from one supplier. The concept allows to cover standard routine measurements as well as high sophisticated detection of individual signals in reflectance, transmission and fluorescence even on the optical resolution limits of a light microscope. Mineralogy, geochemistry and environmental assessment of medicinal clay from southeastern Nigeria

http://www.microscope-spectroscopy.com/


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O.A. Ehinola, M.A. Amos Energy and Environmental Research Group, Department of Geology, University of Ibadan, Ibadan, Oyo State Nigera The mineralogy and geochemistry of trace elements and the quality parameters of some selected clays regarded as a remedy from southeastern Nigeria were investigated for the first time. “Atakiri” is the Igbo name given to the medicinal clay deposit. The clay is used for molding pots, building houses, skin protection and edible by pregnant women to aid in child delivery.

The clay samples were collected from three major existing potential mines sites situated in the following towns: Nteje, Umuawulu, and Ogbu. The samples were analyzed using X-ray powder diffraction (XRD), inductively coupled plasma-mass spectrometry (ICP-MS), atomic fluorescence spectrometer (AFS) and scanning electron microscopy (SEM). The concentrations of fourteen potential hazardous trace elements, including Hg, As, Ba, Se, Pb, Cd, Ni, Cr, Co, Mo, Mn, Cu, V, and Zn in rocks were determined. To evaluate quality of the proposed analytical method, the GBW standard reference materials; GBW 07312 for sediment was also analyzed. The results obtained with the ICP-MS are in agreement with the GBW certified values. Arsenic speciations as well as persistent organic pollutants (POPs) studies were also carried out.

The mineral composition of the studied clay samples is dominantly made up of chlorite, and barium with minor traces of copper and zinc. The concentrations of the trace elements are relatively low compared to coal, shale and sandstone from the area. However, most of the elements are noted to be associated with sulphide minerals and may be harmful to the people residing in this region. Additional work is necessary to determine the health implications of eating the clay raw without any processing.


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Geochemistry and environmental appraisal of some selected coals from Nigeria O.A. Ehinola1, M.A. Amos2, Q.-Y. Liu3

1Energy and Environmental Research Group (EERG), Department of Geology, University of Ibadan, Ibadan, 200284, Oyo State, Nigeria 2Global Petroclean Nigerian Ltd. Ikeja Lagos 3State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China The geochemistry of trace elements and the coal quality parameters of some selected coals from Nigeria were investigated. The samples were collected from seven major existing potential coal mines sites namely: Okpara, Onyeama, Achi, Ezimo, Okaba, Agbogugu, and Ute. Eighteen samples were analyzed using X-ray powder diffraction (XRD), inductively coupled plasma-mass spectrometry (ICP-MS), atomic fluorescence spectrometer (AFS) and scanning electron microscopy (SEM). The concentrations of fourteen potential hazardous trace elements, including Hg, As, Ba, Se, Pb, Cd, Ni, Cr, Co, Mo, Mn, Cu, V, and Zn in coals were determined. To evaluate quality of the proposed analytical method, the GBW standard reference materials; GBW 07312 for sediment and GBW 08401 for coal fly ash were also analyzed. The results obtained with the ICP-MS are in agreement with the GBW certified values.

The mineral matter of the studied coal samples is made up of quartz, kaolinite, and carbonaceous clay minerals. Vertical variations of trace elements observed in two coal mines sites (Okpara and Achi) indicated the distributions of most elements to vary with depth. Compared with average concentration of trace elements in China and Turkey coals, the coals from Nigeria contain a lower concentration. The concentrations of the trace elements are within the range of world coal average. However, most of the elements investigated occur an aluminosilicate and pyrite association and may be harmful to the environment in the process of combustion and utilization.


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Features and distribution of brown coal macerals of Late Pliocene - Early Pleistocene (?), Caldas, Colombia O.P. Gómez Rojas Universidad Pedagógica y Tecnológica de Colombia Calle 4 Sur N°15-134, Sogamoso- Boyacá, Colombia Cel. 310390568; [email protected] The low rank coals present in the volcaniclastic sequence of Aranzazu of late Pliocene - early Pleistocene (?), located on the western flank of the Cordillera Central town of Aranzazu, Caldas department, this unit reaches a thickness of approximately 237 m and has been divided into three members, a lower member composed predominantly of agglomerates, tuffs and tuffaceous sandstones, middle member consisting of tuffaceous sandstones, shales and thin seams of coal, a upper member composed mainly of shale with minor coal seams proportions of agglmerates, tuffs and massive tuffaceous sandstones generally. The environment of deposition of this unit has been defined as a transition between alluvial environments in the base of the unit, affected by volcanic activity in the Cordillera Central, which gradually changes from braided rivers systems to fine-grained meandering rivers or related fluvial re-sedimentation of pyroclastic by lahars, in the form of debris flows and hyperconcentrated for lower member and for middle and upper members defined by coal contents were formed during the dominion of inter-eruptive over the syn-eruptive period in fluvial condition (Borrero et al. 2008). The purpose of this study was to identify the components and petrographic characteristics of macerals present in this unit, which according to the ASTM classification are peat-lignite, the characterization of these coals show high percentages of components huminite (55-70 %) followed by the liptinite (25-32%), mineral matter (14-23%) and low percentage of inertinite minor 5%. The optical characteristics and constituents of coals present in this sequence are typical of soft brown coals, which were affected during its formation by the fall of pyroclasts of the Machín – Cerro Bravo volcanic complex. For identification we used the nomenclature proposed by ICCP; maceral group of huminite (vitrinite precursor) is in high percentages, this is common in all Colombian coals where the principal constituent is vitrinite. Subgroup telohuminite macerals as the textinite and ulminite, present in brow coal was observed with its partial or total preserved lumens and sometimes completely filled by mineral matter, these macerals have strong yellow fluorescence; the detrohuminite fragments is observed as finely divided as macerals humic debris and gels formed from degradation of cell walls between them the attrinite and densinite are found in high proportion which provides strong degradation conditions in the peat at the time of its formation; subgroup maceral gelohuminite is the most abundant, its proportion varies between 24 and 47%, this is represented by bands homogeneous dark grayish brown of gelinite and lower proportion corpogelinite as rounded bodies, homogeneous of the same color. The liptinite group is in proportions greater than 30%, the most abundant maceral cutinite this maceral is in its varieties and tenuicutinite and crassicutinite as threadlike bodies sometimes serrated, dark gray to black in white light and strong yellow fluorescence; the resinite have

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varied size and shape, its color is gray and yellow to orange in fluorescent light; sporinite is in form isolated and sometimes grouped, this maceral is filiform thick and thin walls as micro and macro esporinite the gray color and strong fluorescence, the maceral suberinite present in Tertiary coals have form as cork, like a succession of bricks, strong yellow fluorescence and dark gray; exudatinite is filling the cell lumen. The inertinite occurs in very low proportions that do not reach 5%, this group represented by fusinite, semifusinite with different degrees of preservation, its cell cavities of varying shape, of white color, funginite that has one or more cells sometimes been filled by mineral matter and detrital fragments generated by degradation of this group macerals inertodetrinite occur in very low proportion that do not exceed 1%. Mineral matter consists of oxides, carbonates and silicates mainly proportions of up to 24%, which is to be expected given the contribution of volcanic material. The high content of macerals subgroup gelohuminita detrohuminita and indicates strong decomposition of parenchymal tissues and woody stems and leaves of herbaceous angiosperms and forests which disintegrate more easily than lignified cell walls.


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Reevaluation of vitrinite reflectance suppression through hydrous pyrolysis experiments P.C. Hackley1, A.M. Bove1, F.T. Dulong1, M.D. Lewan2, B.J. Valentine1 1U.S. Geological Survey, MS 956 National Center, Reston VA 20192, [email protected] 703-648-6458 2U.S. Geological Survey, DFC Bldg. 20, MS 977, Lakewood CO 80225 A series of hydrous pyrolysis experiments (Lewan, 1993a) were conducted on immature-early mature source rock and coal samples to test ideas related to vitrinite reflectance suppression and ultimately to improve calibration of petrographic thermal maturity indices. Crushed whole-rock samples (2-4 g) were isothermally heated with deionized water for 72 hours at temperatures of 300°C, 320°C, 340°C, 350°C, and 360°C in SwageLokTM mini-reactors (25-35 ml internal volume). Samples included two Wilcox coals (Paleocene-Eocene, kerogen type III), Alum shale (Cambrian-Ordovician, type II), Huron and Woodford shales (Devonian, type II), Boquillas shale (Upper Cretaceous, type II/III), and Green River shale (Eocene, type I). Following hydrous pyrolysis, samples were mounted in thermoplastic pellets and ground and polished for random reflectance measurements determined via ASTM D-7708 (ASTM, 2012). For the coal samples, reflectance was determined on vitrinite (Ro). For shale samples, reflectance was determined exclusively on solid bitumen (SBRo) that occurs as void-filling material. All new measurements are plotted as points in Fig. 1, which shows two trends based on previous studies (Lewan, 1985, 1993b; Buchardt and Lewan, 1990).

Our measurements of unambiguous vitrinite in Wilcox coal samples follow the results of the previous work, but reflectance measurements of void-filling solid bitumen follow the trend reported by Lewan (1993b) for “suppressed vitrinite”. The previous studies (Lewan, 1985, 1993b; Buchardt and Lewan, 1990) were conducted on solvent-extracted kerogen concentrates that dissolved most bitumen and destroyed the rock fabric needed for petrographic differentiation of bitumen from vitrinite. However, Buchardt and Lewan (1990) did examine thin sections and polished rock surfaces to conclude that some angular, sharp-edged materials were not indigenous or exogenous bitumen but vitrinite-like macerals. Our reflectance measurements on unextracted whole-rock samples with petrographically distinct solid bitumens duplicate the “suppressed vitrinite” reflectance trend of Lewan (1993b) (Fig. 1). Bitumen reflectance is known to be lower than that of co-existing vitrinite at low thermal maturity (Landis and Castaño, 1995). Therefore, these new observations from hydrous pyrolysis experiments could be interpreted to suggest that some reports of “vitrinite reflectance suppression” at low thermal maturity could result from misidentification of solid bitumen as vitrinite (e.g., Hackley et al., 2013), causing lower than expected values of reflectance to be reported as evidence of “suppressed vitrinite”.



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Figure 1. Mean random reflectance measurements of coals and shales subjected to hydrous pyrolysis for 72 hours at varying temperatures.

References ASTM 2012 - D7708-11 Standard test method for microscopical determination of the reflectance of vitrinite

dispersed in sedimentary rocks. In: Annual book of ASTM standards: Petroleum products, lubricants, and fossil fuels; Gaseous fuels; coal and coke, 5, 5.06: ASTM International, West Conshohocken, PA: 821-828.

Buchardt B., Lewan, M.D. 1990 - Reflectance of vitrinite-like macerals as a thermal maturity index for Cambrian-Ordovician Alum Shale, southern Scandinavia: American Association of Petroleum Geologists Bulletin, 74: 394-406.

Hackley P.C., Ryder R.T., Trippi M.H., Alimi H. 2013 - Thermal maturity of northern Appalachian Basin Devonian shales: insights from sterane and terpane biomarkers. Fuel, 106: 455-462.

Landis C.R., Castaño J.R. 1995 - Maturation and bulk chemical properties of a suite of solid hydrocarbons. Organic Geochemistry, 22: 137-149.

Lewan M.D. 1985 - Evaluation of petroleum generation by hydrous pyrolysis experimentation. Philosophical Transactions of the Royal Society of London, 315: 123-134.

Lewan M.D. 1993a - Laboratory simulation of petroleum formation: hydrous pyrolysis. In: Engel, M.H., and Macko, S.S., (Eds.), Organic geochemistry: principles and applications: Plenum Press, New York: 419-442.

Lewan M.D. 1993b - Identifying and understanding suppressed vitrinite reflectance through hydrous pyrolysis experiments. Society for Organic Petrology 10th Annual Meeting Abstracts and Program, Norman, Oklahoma, October 9-13: 1-3.


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Petrology and geochemistry of the lower Miocene lacustrine sediments (Most Basin, Eger Graben, Czech Republic)

M. Havelcová1, I. Sýkorová1, K. Mach2, H. Trejtnarová1, J. Blažek1 1 Institute of Rock Structure and Mechanics, AS CR, V Holešovičkách 41, 182 09 Prague, Czech Republic; +420 266009283; [email protected] 2 Severočeské doly a.s., Doly Bílina, 5. května 213, 418 29 Bílina, Czech Republic The Most Basin is a part of the European Cenozoic Rift System and is the largest of four basins within the Eger Graben in the Czech Republic. The mire, represented by a coal seam of about 30–35 m thick (Holešice Member), is overburdened by lacustrine clays and silty clays with lenticular sand bodies of deltaic origin (upper part of the Holešice Member, Libkovice and Lom Members). The sediments are valuable sedimentary archive of continental environment during the lower Miocene.

Thirty samples of the lacustrine sediments from three localities (Bílina, Tušimice, Osek), including two samples of the Holešice and Lom Member seams, were studied by petrological and organic geochemical methods. The study was financially supported by Severočeské doly, a.s. and by the Czech Science Foundation (Research Grants No. 13-18482S).

In samples of the Holešice Member of the locality Bílina, represented by clay sediments, low concentrations of organic matter were found, in which prevailed huminite particles, with reflectance Rr = 0.30-0.35%, over liptinite and significantly over inertinite. Also in sediments of the Holešice Member of the locality Tušimice organic particles were dispersed in the clay matrix and do not form a continuous position or lamellas. The dominant organic component of sediments were also huminite macerals, especially ulminite, with reflectance Rr = 0.28 – 0.33%. Mineralized micro bands of attrinite and densinite were other identified huminite macerals, in which were dispersed particles of corpohuminite, and liptinite and inertinite macerals, especially funginite, macrinite and inertodetrinite.

In samples of the Libkovice Member of the locality Bílina, fine-grained silty clays with low organic carbon and organic matter, liptinite macerals were dominated especially alginite, sporinite and liptodetrinite, less resinite and bituminite. Less frequent and sparsely dispersed were particles of ulminite and fusinite, funginite and inertodetrinite. Ulminite reflectance ranged from 0.28% to 0.33%.Similar compositions were found in sediments of the Libkovice Member of the locality Tušimice. The base matter consisted of clay minerals with sparsely dispersed organic particles, especially with liptinite macerals (alginite, sporinite, liptodetrinite and less resinite). The huminite occurred as ulminite, with reflectance Rr = 0.28 – 0.31%, gelinite, korpohuminite and tissue fragments in attrinite.

Samples of the Lom Member of the locality Osek represented clayey sediment and clayey coal with organic carbon content <30 wt. %. The sediments dominated by huminite macerals: ulminite, with reflectance Rr = 0.30 – 0.36%, corpohuminite, textinite, densinite, with the exception of sediment from the seat rock and overburden with the prevailing liptinite macerals: alginite, sporinite, liptodetrinite, resinite and cutinite. Inertinite content does not exceed 10 vol. %. The most frequently occurring was funginite in the form of fungal sclerotia. Other inertinite


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macerals: fusinite, macrinite and inertodetrinite are the remains of vegetation fires. Particles semifusinite rather indicates weathering, biochemical or microbial decomposition of plant tissues.

In most of the samples n-alkanes formed the major component in total extracts (content of n-alkanes 5.3 – 82.4%). In almost all sample extracts higher n-alkanes with carbon numbers in the n-C26 – n-C33 range prevailed, with the dominance of odd number of carbons and with maximum values at n-C27, n-C29 and n-C31, which is the distribution typical for low thermally affected organic matter derived from hydrocarbons of higher plants. Most sample extracts did not show the monomodal type of distribution, but there were maxima at mid- and short-chain n-alkanes, as the contribution of bacteria, algae (diatoms), and aquatic plants.

Isoprenoids pristane (Pr) and phytane (Ph) were found in all sample extracts. The values of their ratio Pr /Ph in the range of 0.39 – 1.92 indicates that sedimentation took place in the redox environment, with a few exceptions having higher oxygen access. Pr/n-C17 and Ph/n-C18 ratios are low, due to microbial activity in the environment.

In several samples appeared in a large representation the compound perylene, which is considered by some authors as a product of fungi.

The content and representation of sesqui-, di-, and triterpenes, components produced by a variety of plants indicate representation of plant matter in samples. Their content corresponded well with huminite content in the samples. Some of the identified terpenes are characteristic for a plant family (cuparene for Cupressaceae). However, most terpenes are non-specific such as α (H)-phyllocladane, which was detected in all samples. Also totarol, from cedrus and cypress resin (Cupressaceae), was found in the most sample extracts, and similarly sugiol (Cupressaceae, Podocarpaceae and Araucariaceae). In almost all studied extracts were found triterpenes: des-A-lupane and oleanenes, and in some of them were found degraded triterpenes after terpene oxidation, and can thus be deduced the oxidation conditions of organic matter storage for these samples. It was also confirmed by the ratio Pr/Ph. Also hopanes were identified in all extracts (except 1 sample).

The consistent results of petrographic and chemical composition of sediments with dispersed organic matter of the Holešice Member indicate the relatively stable surface development of the sediments in the lake environment. In the carbon content increase of the Holešice and Lom Members participated the storing of fungi debris and the contribution of microbial activity, which led to the formation of clayey coal. In the chemical composition dominated sesqui-, di-and triterpene compounds. Sediments of the Libkovice Member contained low concentrations of organic carbon and low proportions of small organic particles dispersed in the sediment. In the extracts of these samples prevailed hopanes, perylene and sulfur after the action of microorganisms. The base of the organic fraction formed also remains of terrestrial plants and liptinite macerals, especially alginite, liptodetrinite and bituminite that are typical for lacustrine sediments.


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Peat-petrographical characteristics of topogenous mires in relation to coal formation conditions S. Kalaitzidis1,2, K. Christanis2 1 Integral Resource Consulting Pty Ltd. Brisbane, Australia; +61 (0) 458 057 158; [email protected] 2 Department of Geology, University of Patras, Rio-Patras, Greece

The geological study of modern peat-forming environments contributes significantly to the understanding of the coal-forming conditions that prevailed during past geological times. The present study focuses on the processes taking place in the peatigenic layer by detecting the transformation stages of initial plant material to peat constituent and macerals, and the correspondence to the respective ecological conditions.

Cores from the intermontane peatlands of Philippi (Eastern Macedonia) and Nissi (Western Macedonia) and the coastal peatland of Keri (Zakynthos Island) in Greece, were examined. The study covered the entire peat-accumulation time span for the Nissi and Keri mires, whereas for the Philippi peatland the period from Upper Weichselian till Middle Holocene has been studied.

The objective was to determine the petrographical characteristics of the organogenic sediments and of the peat-forming plants that grow on the surface of the modern mires of Nissi and Keri. Organic petrographical techniques were applied to intact peat and plant samples, for both qualitative description and maceral analyses purposes.

The intermontane Philippi and Nissi peatlands comprise similar peat-forming environments, since Cyperaceae, mainly Cladium mariscus and various Carex spp., constitute the main peat-forming plants, and additionally both are affected by karstic aquifers. On the contrary, in the brackish mire of Keri Scirpus maritimus and Juncus maritimus are the dominant species.

These different geological and ecological settings, along with the significant climatic variations during the Upper Weichselian-Holocene transition were recorded to the maceral assemblages of the peat sequences, in relation to the degrees of fragmentation, humification, oxidation and gelification of the organic matter, as well as to the ratio of sedimentary vs. sedentary fractions.



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Instrumental methods of hard coal structural analysis - selected problems A. Matuszewska Faculty of Earth Sciences, University of Silesia, Będzińska 60, 41-200 Sosnowiec, Poland; [email protected]

Technological progress and also the growing pro-ecological requirements in the domain of processing and burning of coals and their products encourage to use, apart from classical, also other, modern analytical methods, investigating deeper the coal structure.

In this scope, there are chromatographic techniques of fractionation and analysis, which have been developed especially well. This allows to perform the analyses of the molecular phase of coal. Among coal thermolytic products, the PAHs group of compounds draws special attention, especially in the context of ecology, as well as also, e.g., in the investigations of coal metamorphism. The coal researches from the region of magmatic intrusion former activity (Sośnica mine, Poland (e.g. Matuszewska 2007)) indicate, that the transformation tendencies of PAHs as a result of contact metamorphism, are similar to these, having place during coking processes, as well as during other coal thermolytic processes.

The investigations of the macromolecular coal phase constitute another problem. Analysis of the phase is very difficult because of its complex chemical and physical architecture. Infrared spectroscopy (IR), in the modern version of the micro- FT IR, has broadened its domain of researches, making possible, e.g., direct analysis of particular coal macerals, without their separation (e.g. Hacura et al. 2003). The Raman spectroscopy, applied usually to estimation of graphitization degree, may be used also in researches of coalification processes of coals, especially, when accelerated by contact metamorphism (Fig. 1).

The graphitization process can be investigated with special efficiency, when the method of TEM (transmission electron microscopy) is used (e.g. Rouzaud, Oberlin 1990; Duber 2011). In the Figure 2 the micro-texture is shown of the coal sampled from the neighborhood of the intrusion mentioned above. The light areas are domain of order of the structure in the form of parallel layers.

Fig. 1. The Raman spectra of the coal sample from the neighbourhood of intrusive body (a) and of the sample

from the distance of 1.7 m of the contact (b), Sośnica mine, Poland.

a/ b/



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Recognition of the chemical structure of coal macromolecule is aided also by researches of

the volatile destruction products obtained by various pyrolytical techniques (including: Py-GCMS, Rock Eval, DTA/OTA [for the coal from the contact zone mentioned earlier, the investigations were already partially described in some works, respectively: Matuszewska 2003, 2004; Matuszewska, Cebulak 2006]).

The results obtained characterize, to a certain degree, construction of the macromolecular coal network on the basis of composition of the destruction products. Some of the laboratory coal thermolysis experiments can be useful as an approximate simulation of the natural processes, e.g. of the contact metamorphism.

Figure 3 depicts the exemplary spectra of synchronous luminescence of the aromatic fraction of extracts from humic and sapropelic coals. There is a distinct diversification of the spectra shapes, outcoming from the various precursor materials. This is a reason , that this method could be used for solution of some coal classification problems. The comparative results of fluorescence analysis of the coal products have also an ecological aspect , because of a possibility of the PAH`s contribution comparison in the coal molecular phase, or also, in the various coal products (e.g. Matuszewska, Czaja, 2002).

On the basis of the own and literature data, a series of modern instrumental methods were presented here in application to coal investigations. The methods chosen here, were used successfully in the own researches. The results obtained have confirmed the usefulness of the methods, among others, to comparison of the natural and laboratory processes of thermal coal destruction, to solution of some coal classification problems and to evaluation of the potential environmental risk by coal products.

Fig. 3. Synchronous luminescence spectra (λ=23nm) of the extracts from humic (a) and sapropelic (b) coals

Fig. 2. Transmission electron microscopy, dark field technique, coal from the intrusive contact zone


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References Duber S. 2011 - Nanostruktura i mikrotekstura antracytów. Wyd. U.Śl., Katowice. Hacura A., Wrzalik R., Matuszewska A., 2003 - Application of reflectance micro-infrared spectroscopy in coal

structure studies. Anal Bioanal. Chem., 375: 324-326. Matuszewska A. 2003 - Preliminary results of geochemical and petrographic investigations of hard coal from

mine ”Sośnica”, heat-affected by igneous intrusion. Zeszyty Naukowe Politechniki Śląskiej, Seria: Górnictwo, 257, 1599: 109-129.

Matuszewska A. 2004 - Some aspects of the use of Py-GC/MS to investigate the composition of of the aromatic fraction of hard coal pyrolysates. Acta Chromatographica, No 14, 215-230.

Matuszewska A. 2007 - Wybrane wskaźniki geochemiczne zmian materii organicznej wegli kamiennych pod wpływem oddziaływania intruzji magmowej. Przegląd Geologiczny, 55, 4: 298.

Matuszewska A., Cebulak S. 2006 - Oksyreaktywna analiza termiczna w badaniach węgla o różnym stopniu metamorfizmu. Materiały recenzowane z XXIX Sympozjum nt. Geologia Formacji Węglonośnych Polski, AGH, Kraków.

Matuszewska A., Czaja M. 2002 - Aromatic compounds in molecular phase of Baltic amber – synchronous luminescence analysis. Talanta, 56: 1049-1059.

Rouzaud J.N., Oberlin A. 1990 - The characterization of coals and cokes by transmission electron microscopy. In: Advanced methodologies in coal characterization. Eds H.Charcosset, B.Nickel-Pepin-Donat, Amsterdam-Oxford-New-York-Tokyo, Elsevier: 311-355.


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Multivariate studies of relationship between petrography and proximate analysis and its influence in the hardgrove grindability index for some thermal coals located in North Central Boyacá, Colombia

Y.C. Pérez1, O.P. Gómez1, J.J. Herrera2, A.J. Arias1, C.A. Fragozo1 1Universidad Pedagógica y Tecnológica de Colombia UPTC Calle 4 Sur N°15-134, Sogamoso- Boyacá,

Colombia; [email protected]; [email protected]; [email protected]; [email protected]

2Jorge Humberto Arias Consultores Mineros JHA; [email protected]

Colombian coals are most desired and required in national and international markets for its features and increased consumption. In order to increase our knowledge of our coals, to understand their behavior and to have more information about their properties, we require more studies. With the results we are interested in improving the use of our coal, in particular, those which are in the central region of Colombia; about this zone, there are not a lot of information about it because of small-medium scale of the mining. For this study, a total of 68 samples of coal were taken from different active extraction fronts in the northern region of Boyacá. The samples belong to the Guaduas formation, that is located in the center of the Eastern Cordillera of the Colombian Andes. This lithostratigraphic unit was formed in paralic environments and it is characterized by bituminous coal, which is used for power generation. The samples were taken and prepared following ASTM standards; this study includes the determination of 11 parameters, corresponding to the petrographic analysis as percentage volume of macerals, microlitotypes and reflectance of the vitrinite; proximate analysis and other analysis as determining Hardgrove Grinding Index and FSI. The results are calculated based in ash-free dry in order to establish the variations according to the different sites. This study shows the distribution of data and correlations between different parameter to determine what variables have the most influence on the HGI, using multivariable analysis. The results show that the macerals vitrinite group are the main components in these coals and their percentage ranges from 45 to 79%, followed by macerals of the inertinite group from 4 to 22% and mineral matter from 3 to 42% and liptinite a lesser proportion from 2 to 14%; due to abundant macerals, the principal microlitotypes are vitroinertite between 5 and 44%, vitrite between 7 and 36%, minerite between 1 and 25%, carbopoliminerite between 3 and 24% and trimacerite V, between 2 and 23%. The vitrinite reflectance determines that these coals are in a range between high volatile bituminous and lignite; the classification according to INGEOMINAS with values between 0.37 and 0.97. The results of the proximate analysis the percentage of volatile matter between 28 and 44%; fixed carbon between 32 and 56%; ash between 3 and 36%; sulfur between 0.6 and 4%; residual moisture between 0.6 and 7% and calorific value between 4987 and 7957 cal / g. In terms of HGI the values were between 33 and 74 and FSI between 0 and 8. The correlation coefficients obtained between the variables as reflectance and volatile matter ash free dry (slcz) is -0.75, indicating a high negative correlation, with increasing degree of coalification is observed higher values of vitrinite reflectance and a decrease of volatile matter content as expected. The coefficient between the






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variables of reflectance and fixed carbon (Slcz) is 0.75 showing a direct relationship between the two variables. Correlation of the calorific value (Slcz) with vitrinite reflectance has the coefficient value of 0.90, showing a higher correlation between these two variables compared with the previous for these coals in the north central region of Boyacá. For multivariate analysis three sets of input were identified, a) related only to the petrographic features as vitrinite, liptinite, inertinite, mineral matter, reflectance; b) related physicochemical characteristics as ash, calorific value (Slcz), fixed carbon (Slcz), humidity (lcz) and FSI; c) combining petrographic and physicochemical characteristics fixed carbon (Slcz), reflectance, calorific value (slz), volatile matter (Slcz), with adjustment of 036, 0.45 and 0.55 respectively. The results show little adjustment in multivariate linear regression model, as it can be seen the greatest adjustment reached was 0.55, which was obtained with the variables that determine the degree of coalification and an atypical behavior in these coals.


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Histograms of the gray scale gradient directions in coke texture analysis M. Piechaczek, A. Mianowski Institute for Chemical Processing of Coal, 1 Zamkowa St., 41-803 Zabrze; +48 32 271 0041-241; [email protected]

Coke microtexture is a unique feature of any coke and determines its quality. Microtexture refers to the nature of the carbon in coke molecular structure, its crystalline ordering, degree of the optical anisotropy etc. In recent years, a lot of microtextural terminologies and classifications were developed. In every case, qualitative and quantitative analysis of the coke textures, provides a large number of results. Results in the form of percentage values (sometimes over 20 texture types) are difficult to use in the algorithms of the coke quality prediction. In this study authors propose to use the image processing to change the typical texture analysis results on one dimensionless numerical value. As a technique of the image analysis the measurement of the grey level gradient and direction of this gradient is used. The combination of the qualitative and quantitative textures analysis and image analysis results is proposed to use (Xtx).

Test cokes were imaged by registering the isolated types of textures in colour. Images were taken in polarized light with Lambda plate, using magnifications x25 and x200. Scaled images of textures were analysed for gradient direction of a brightness function (colour-> grey scale) with a threshold 25 x 25 pix. An ellipse from the histogram of the grey scale directions of all images’ pixels is determined (Fig. 1 and Fig. 2). An ellipse is characterised with 2 axis (a and b) which are also calculated. Based on this data the texture elongation index (W) is determined.

According to this method values of the individual elongation index W for every texture were calculated. The elongation index does not depend on the coke quality and it is constant for every coke.

Fig. 1 Histogram and ellipse of a ribbon texture



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Fig. 2 Histogram and ellipse of a circular texture

(with a decrease of molecular order degree the ellipse becomes a circle W → 0)

The study shows that the better molecular order of the structure, the higher elongation index is obtained. For isotropic texture the ellipse becomes circle a=b and the W = 0. The elongation index increases from incipient anisotropic (W = 0,13), through circular (W = 0,19-0,43) and lenticular (W = 0,61-64) to ribbon texture (W = 0,65-85) in accordance to molecular order. Parallel, quantitative and qualitative analyses of coke textures were performed. From combination of the qualitative and quantitative textures analysis and image analysis results, the characteristic textural dimension Xtx is obtained:

Utx – volume of texture (values 0-1);

Wtx – elongation index of texture; It was discovered that the characteristic textural dimension Xtx is in linear correlation with CRI. The characteristic textural dimension is inversely proportional to CRI. This method may be the introduction to the automated textures analysis. Acknowledgements: The Smart Coking Plant R&D Project (Innovative Economy Programme (POIG), Contract no 01.01.02.-24-017/08) and Statutory R&D Project IChPW no. 11.13.018 /2013 are acknowledged for its financial support. Thanks for Dr Mariusz Minkina (SGL Group, Racibórz) for providing the materials for image measurement. References Kolowca M. 1995 - Komputerowa analiza mikroskopowych obrazów koksów elektrodowych (eng. Computer

analysis of microphotographs of the electrode cokes) PhD Thesis, Cracow. ASTM D5061-7 Microscopical determination of the textural components of metallurgical coke.


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Petro-chemical characterization of some borehole coal core samples from virgin area in Damodar Valley Basin, Eastern India A.K. Singh, N. Choudhury, P. Boral, N. K. Shukla, S. Kumar, B. Ghosh, R. Singh, A. Sinha CSIR-Central Institute of Mining & Fuel Research, P. O. FRI, PIN-828108, Dhanbad, India; +919431317806; [email protected] Few borehole coal cores were studied in this investigation through detailed chemical and petrographic techniques to have a thorough understanding on the coals of the virgin block in eastern part of India. The facilities of advanced petrographic characterization through Leica make DM4500 Polarizing microscope & chemical analysis following different Indian Standards (BIS) using equipments at CSIR-CIMFR laboratory were used for this investigation.

The moisture, in general, varied between 2.0 and 8.0 %, volatile matter between 25 and 36% on air dried basis. On equilibrated basis moisture between 3.0 and 6.5.0%, volatile matter between 26 and 35%. Gross Calorific value ranged from up to 27.63 MJ/kg. The ash content of the overall samples is medium in range (10 to 34%). Among ultimate constituents carbon was between 35 and 65%, hydrogen up to 5%, nitrogen up to 1.5% and sulphur up to 0.6%. The HGI values (50-65) indicate that, these coals may be ground with moderate ease.

Among petrographic constituents, in general, the vitrinite was higher between 55 and 75 % and low inertinite (10 - 25%); while mineral matter on visual basis was also moderate (6.0 - 25.0%). The reflectance value of the overall samples in boreholes varies between 0.60-0.75 percent up to semi/medium caking nature. Liptinite was substantially lower in the studied samples.

From the generated data, it can be concluded that most of the coal samples are sub-bituminous to high volatile non-caking bituminous category coal as per Indian Standards IS: 770-1977, (Reaffirmed in 2001), while some samples even qualify up to semi-medium coking coals.



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An influence of geological pressure on the optical texture of coal Ł. Smędowski1, S. Duber2, A. Matuszewska2 1Institute for Chemical Processing of Coal, 1 Zamkowa St., 41-803 Zabrze; +48 32 271 0041-355; :

[email protected] 2University of Silesia, Faculty of Earth Science, 60 Będzińska St., 41-200 Sosnowiec

Structure of bituminous coal and its features strongly depends on geological conditions in which process of transformation of organic matter had occurred. It is commonly assumed, that temperature and pressure are the most important factors that have influence on above mentioned process. During the metamorphism those factors may undergo violent (in geological terms) and local (limited to small area) changes as a result of igneous intrusion. The aim of this work is to study an effect of the pressure on optical texture of coal.

Two coal samples collected from the Sośnica coal mine, Poland, were analyzed in this study. Sample 1 was taken in immediate proximity of intrusion and it was strongly changed under the high temperature and pressure. It can be assumed that it was a natural char sample. Sample 2 was collected at the distance of 15 metres from the intrusion and it was not under the influence of the intrusion. This unchanged sample was pyrolised in laboratory furnace to temperature of 950 centigrade, in Argons atmosphere. Obtained char (sample 3) was analyzed to compare its features with those characterized a char sample that was formed under geological conditions (temperature and pressure).

Microscopic characteristics of samples microtexture were determined with reflected light optical microscope Axioskop MPM-200 (Opton-Zeiss, Germany) using monochromatic plane polarized light of λ=546nm. Coal grains of ≤3.0mm diameter were embedded in epoxy resin and polished according to the procedure recommended by the ICCP standard. The apparent maximum (R’max) and minimum (R’min) reflectance values were automatically measured on randomly oriented coal grains, in immersion oil, at the magnification 500×. To accurate determination of reflectance indicating surface (RIS) a modified Killby’s method was used (Killby, 1988; Duber et al., 2000). Values of R’max and R’min were processed and average values of ellipsoidal RIS radii: RMAX, RINT, RMIN were determined as well as values of the radius of a spherical RIS, Rev and RIS anisotropy, Ram (Table 1).

Table 1. Values of reflectance indicating surfaces (RIS) parameters.

Sample RMAX RMIN Rbi = RMAX - RMIN Rev Ram

1 8.65 5.59 3.06 6.33 0.220

2 0.92 0.81 0.11 0.85 0.080

3 7.57 6.72 0.85 7.21 0.065

It is clear that the sample 2 (unaltered coal) is characterized by the worst developed texture. It has the lowest values of all refletance parameters and the lowest Rev value, that describes the volume of the RIS. Comparising the optical feauters of sample 1 and sample 3 it can be concluded that the



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natural char has generally better organized texture than the coal that was pyrolised in non-pressure conditions. Sample 1 is characterized by significantly higher values of Rbi and Ram parameters than sample 3 and it indicates that the difference between their anisotropies is very high – sample 1 consist of better ordered molecular oriented domains (MOD). It can be also seen that sample 3 is characterized by the higher value of Rev. It also indicates that the molecular ordering of this char is lower than that observed for natural char. Rev depends on the both RMAX and RMIN so the high value of this parameter results from the relatively high value of sample’s 3 RMIN which corresponds poor degree of ordering through the direction perpendicular to the layers of the coal bed. Basing on the RMAX and RMIN values shape of each RIS was drawn (Fig. 1).

Fig. 1. Shapes of reflectance indicating surface (RIS) calculated for samples studied.

Shapes of all three curves directly confirm conclusions described above. The presence of pressure very strongly affects the process of molecular ordering that took place during the heating of coal. The natural char sample is characterized by better ordered and more anisotropic optical texture than the sample of char that was heated at the similar temperature but without the pressure influence. Hence, it can be concluded that the geological pressure has the significant influence on the optical texture of coal. So it should be also emphasized that the textural parameters of coal can not be used as a geo-thermometer, because they are strongly dependent not only on the temperature but also on the pressure. Acknowledgements: The Smart Coking Plant R&D Project (Innovative Economy Programme (POIG), Contract no 01.01.02.-24-017/08) is acknowledged for its financial support. References Duber S., Pusz S., Kwiecińska B. K., Rouzaud J.-N. 2000 - On the optically biaxial character and heterogeneity

of anthracites. International Journal of Coal Geology 44: 227 – 250. Kilby W. E. 1988 - Recognition of vitrynite with non-uniaxial negative reflectance characteristics. International

Journal of Coal Geology 9: 267 – 285.


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Petrographic consideration of coals from the Karoo Basin, Botswana: expanding the limited data pool N.J. Wagner1, M. Johnston2, J.C. Hower2, M. Ndhlaso1 1School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Private Bag X3, 2050,

Johannesburg, South Africa; [email protected] 2University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511,

United States of America As noted in a publication by Hower et al. (2012) there is limited published data on many of the Permian coalfields in sub-Saharan Africa, especially in the area of coal petrology. In this study, 4 sets of coals from 4 different Botswana coalfields were analysed petrographically (total of 54 samples, most from cores). Botswana, with a comparatively small population in a large, relatively arid country, primarily relies on South Africa to make up the significant shortfalls in its electricity supply. There is currently only 1 active mine (Morupule Colliery) supplying 1 active pf power station (Morupule coal-fired plant, 132 MW) in Botswana. However, extensive exploration is underway, with plans to significantly increase power generation by 2017 (estimated at 57% per annum) by the expansion of the pf power station (underway), installation of circulating fluidised beds ((CFB) currently on hold due to complications of combusting the coal), underground coal gasification (unlikely as seams are relatively shallow), and coal bed methane (significant exploration happening). The renewable and biomass sectors are also growing, from a 0% base for the former (despite very high solar insolation). Botswana may have coal reserves of over 200 billion tons, but limited information is available about the quality of the coal, and whether the coal is suitable for the different conversion technologies currently on offer. Unfortunately, there have already been instances of failed technology due to incomplete understanding of the coal.

The Botswana coalfields form part of the Permian Karoo Supergroup, and the Karoo Basin covers an area of 550 000km2. As with most southern African coals, Botswana coals have high to very high inertinite contents, variable vitrinite and semifusinite contents. Rank values appear to vary in the bituminous range, but are believed to be primarily low rank. As with other southern African Permian coals, mineral content is variable, consisting primarily of clays and quartz, with carbonate and pyrite present.

The polished blocks were analyzed using a Leica DM4500P petrographic microscope fitted with a J&M Spectrolytic system for vitrinite reflectance determination (ISO 7404 part 3). An automated point counting stage and Petrog software fitted to a Zeiss Universal microscope was used for the maceral and abnormal condition analysis, the former in accordance with ISO 7404 - 4, at a magnification of x500 under oil immersion. Micrographs (photographs) were taken using an Axiovision digital camera attached to the microscope. The abnormal condition analysis was conducted following in-house development, and publications by Wagner (2007). The intention of the analysis is to quantify abnormal features, such as extensive fissuring and cracking, mineral alteration, heat affect, and so on.

Results from the 1st set of coal samples (not cores) showed extremely high inertinite contents, and extremely low vitrinite contents. The highest vitrinite content determined was for sample 1310 at 11.5% (by vol mmf); for all other samples analysed, vitrinite content was below 5%. The inertinite consisted mainly of inertodetrinite, followed by semifusinite and secretinite (photo 3). The liptinite content can be considered to be typical of southern African coals, and did not appear to have been affected by weathering (hence physical weathering rather than oxidative weathering). Some particles contain a significant amount of liptinite, in the form of spores and pollens (photo 1). All samples were highly fissured or cracked or discoloured, all signs of the impact of water insitu, most likely following coalification (photo 2). An ancient riverbed is



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located in the proximity of the coal seam. Rank determination was difficult due to the very low vitrinite content. Based on two samples (and only 50 readings) the mean random vitrinite reflectance values obtained were 0.45 and 0.47 % RoVmr, placing these coals in the Low Rank A / sub-bituminous coal category. Epigenetic carbonate minerals were very prevalent (photo 4).

As these samples are targeted for use in a CFB it would be necessary to determine the impact of the extremely high inertinite content and the extensive fissured / cracked nature of the coal on the process. It is likely that the coal will be more reactive than anticipated due to enhanced surface area and thus the inertinite macerals may react at a lower temperature than typical for unweathered inertinite-rich coals.

References Hower J.C, Wagner N.J., O’Keefe J.M.K, Drew J.W., Stucker J.D, Richardson A.R. 2012 - Maceral types in

some Permian southern African coals. International Journal of Coal Geology, 100: 93–107.


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Palaeobotany and vegetation successions recorded in coal – utilising the lost tool of etching N. Van de Wetering, J. Esterle Department of Earth Sciences, University of Queensland, QLD 4072, Australia; [email protected] The proposal of phyteral identification was introduced by Cady in the early 1940’s |(Cady 1942), in an effort to recognise the original floral components that constituted coal. Few studies have utilised this scheme, and its application seemed limited due to difficulty in phyteral identification following the degradation, compression and coalification of plant matter. Later research investigated the effectiveness of chemical etching and phyteral identification through a high-resolution study of coal blocks (n=234) in coal measures of the Late Permian, Bowen Basin, Australia (Van de Wetering et al. 2013). This presentation describes the methods and techniques performed in the feasibility study. This includes discussion of classification systems developed from palaeobotanical and modern botanical cellular biology to obtain data from etched coal blocks. Palaeobotanical data is compared with δ13C isotopes, lithotype logging, palynology, palynofacies analysis and maceral petrography, to show their corresponding relationships. Analyses of phyteral change were found to record transitions between unique palaeobotanical assemblages of flora, each constrained by environmental and depositional factors controlling their distribution. Lithotypes were effectively correlated with specific vegetation communities. These refined methods of etching and phyteral identification represent a renewed understanding in palaeoclimatic, and palaeoecological aspects of coal forming environments. References Cady G.H. 1942 - Modern Concepts of Physical Constitution of Coal. Journal of Geology, 50: 337-356. Van de Wetering N., Esterle J., Baublys K. 2013 - Decoupling δ13C response to palaeoflora cycles and climatic

variation in coal; a case study from the Late Permian Bowen Basin, Queensland, Australia. Palaeogeography, Palaeoclimatology, Palaeoecology: 1–57.



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Organic geochemical properties of matrix and xylite coal from the Kolubara and Kostolac basins, Serbia D. Životić1, A. Bechtel2, R. Sachsenhofer2, R. Gratzer2, D. Radić3, M. Obradović3, K. Stojanović4 1 University of Belgrade, Faculty of Mining and Geology, Djusina 7, 11000 Belgrade, Serbia; +381 11 3219 251; [email protected] 2 Department Angewandte Geowissenschaften und Geophysik, Montanuniversität Leoben, Peter-Tunner-Str. 5, A-8700 Leoben, Austria 3 University of Belgrade, Faculty of Mechanical Engineering, Kraljice Marije 16, 11000 Belgrade, Serbia

4 University of Belgrade, Faculty of Chemistry, Studentski trg 16, 11000 Belgrade, Serbia The biomarker contents of matrix and four type of xylite coal of different colour (pale yellow, dark yellow, brown and black) from the Upper Miocene lignite from the Kolubara and Kostolac have been analyzed by gas chromatography–mass spectrometry.

The yield of the soluble organic matter (bitumen) is high and ranges from 15.31 to 273.24 mg/g Corg (Table 1). Generally speaking, pale yellow type of xylite coal from both basins has the highest content of the soluble organic matter. It has been attributed to the high proportion of biogenic and diagenetic compounds. In the studied samples, the contents of saturated hydrocarbons (1.83 – 6.71 wt. %) and aromatics (0.50 – 2.35 wt. %) are low, while the contents of asphaltenes (22.22 – 61.43 wt.%) and NSO compounds (33.12 – 73.84 wt. %) are high, as expected for immature terrestrial organic material (Table 1).

The main constituents of the saturated fraction in all studied samples are diterpenoids, n-alkanes, hopanoids, triterpenoids and sesquiterpenoids. Steroids were identified in low amounts. Diterpenoids of the phyllocladane, pimarane, isopimarane, norpimarane and kaurane are the major compounds in the total extracts. The highest value of diterpenoids has been identified in pale yellow type of xylite coal from both basins, while the lowest was identified in matrix coal. The 16α(H)-Phyllocladane and pimarane are by far dominant in the saturated fractions of all types of xylite coal. A high amount of 16α(H)-phyllocladane indicates that the lignite forming plants in part belonged to the conifer families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Sciadopityaceae and Phyllocladaceae, while the high abundance of pimarane suggests Pinaceae, Taxodiaceae and Cupressaceae (Otto, Wilde, 2001).

Sesquiterpenoids of the longifolane, drimane, cadinane and cedrane and triterpenoids of the oleanane and lupane series are identified in low content in all samples.

The n-alkane patterns of the xylite coal are dominated by long-chain homologues (C27-C31) with a maximum at n-C29 and a marked odd over even predominance, indicating a significant contribution of epicuticular waxes. The values of the CPI (carbon preference index) are in accordance with the low rank of the lignite.

The hopane composition in all samples is characterized by the presence of 17α(H)21β(H), 17β(H)21α(H) and 17β(H)21β(H) compounds with 27-31 carbon atoms, with exception of C28 homologues. C3117α(H)21β(H)22(R)-Hopane is the most abundant compound in the saturated fraction of the all studied samples. The contents and distribution of hopanes imply the peatification in a suboxic to oxic environment for the all studied samples.



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Diterpenoids are main constituents in aromatic fraction indicating significant contribution of gymnosperms to the precursor OM (Bechtel et al., 2002). The aromatic diterpenoids consist of norabieta-6,8,11,13-tetraenes, norabieta-8,11,13-trienes, dehydroabietane, simonellite, retene, sempervirane, totarane, hibaene, tetrahydroretene and 2-methylretene, with simonellite and dehydroabietane predominating in all of the samples from the Kostolac basin.

Although the nonhopanoid triterpenoids represent a minor component of saturated fraction, these compounds predominate in aromatic fraction of coal extracts from Kolubara basin. This result shows that angiosperms also contributed to the organic matter (Bechtel et al., 2002).

Due to the enhanced aromatization of angiosperm derived triterpenoids, the ratio of diterpenoids to sum of di- and terprenoids in saturated fraction, shows extremely high and uniform values (above 0.92) in all studied samples, indicating that conifers nearly exclusively contributed to xylite and matrix coal formation. Therefore, in order to estimate the contribution of gymnosperm and angiosperm vegetation in the ancient peat bogs we have used the ratio of diterpenoid and angiosperm-derived triterpenoid aromatic biomarkers. The lower values of this ratio (0.24-0.50) in samples from the Kolubara basin indicate increasing proportion of angiosperms within the peat-forming vegetation.

Table 1. Group organic geochemical parameters

Samples C dborg

(wt.%)

Extract yield

(mg/g Corg)

Alkanes (wt.%)

Aromatics (wt.%)

NSO compounds

(wt.%)

Asphaltenes (wt.%)

Kolubara Matrix coal 39.07 94.33 1.83 0.83 69.50 27.84 Xylite coal-pale yelow 48.08 110.81 4.34 1.12 33.12 61.43 Xylite coal-dark yelow 57.72 62.49 3.43 0.91 49.00 46.66 Xylite coal-brown 56.88 49.88 1.83 0.75 71.20 26.21 Xylite coal-back 56.03 22.12 3.71 1.84 48.17 46.27

Kostolac Matrix coal 46.73 27.60 5.32 2.35 56.84 35.48 Xylite coal-pale yelow 60.85 273.24 3.43 0.50 73.84 22.22 Xylite coal-dark yelow 59.78 46.57 6.71 1.23 45.63 46.42 Xylite coal-brown 55.14 30.26 4.53 1.71 55.95 37.80 Xylite coal-back 59.82 15.31 5.12 2.13 50.00 42.75

References Bechtel A., Sachsenhofer R.F., Gratzer R., Lücke A., Püttmann W. 2002 - Parameters determining the carbon

isotopic composition of coal and fossil wood in the Early Miocene Oberdorf lignite seam (Styrian Basin, Austria). Org. Geochem. 33: 1001–1024.

Otto A., Wilde V., 2001 - Sesqui-, di-, and triterpenoids as chemosystematic markers in extant conifers – a review. Bot. Rev. 67: 141–238.


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organic geochemistry of the kolmani river-1 well, upper...

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