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Organic matter present in uraniferous paleoplacer deposits in the Elliot Lake-Blind River region, Canada, falls into two distinct types based on morphology, reflectance in oil, and bireflectance. Organic matter of the second type is primary and biogenic and probably represents the metamorphosed remnants of cyanobacterial mats. It consists of finely laminated kerogens with high reflectance (%Romax — 4.02-7.31) and high bireflectance. Under cross-polars it shows a textural pattern similar to that of thinly laminated organic matter. The level of thermal maturation is in the range of prehnite-pumpellyite to lower greenschist metamorphic facies. The first type consists of homogeneous, globular, migrated bitumen. These bitumens are isotropic to weakly anisotropic with a reflectance ranging from 0.72 to 1.32% (Romax)Globular bitumen is essentially unmetamorphosed and follows the (normal) bitumen maturation pathway. Both types of organic matter have contributed to the uraniferous mineralization of the El...

Resinite, hand picked from a subbituminous coal in the Hat Creek No. 1 deposit in south central British Columbia, Canada, was subjected to oxidation in air at temperatures between 50°C and 400°C. The initial and oxidized resinite samples were analyzed for variations in molecular structure by the use of Fourier transform infrared (FT-IR) photoacoustic spectroscopy and 1H and 13C nuclear magnetic resonance spectroscopy. The changes in molecular structure determined were correlated with differences observed in optical reflectance and fluorescence properties. The resinite in its initial state was predominantly aliphatic in nature and could be characterized as a diterpenoid, with alkene and carboxylic functionalities exocyclic to the six-membered rings composing the diterpenoid skeleton. Oxidation between 50°C and 100°C resulted in only minor structural changes. During oxidation between 100°C and 250°C there were very significant changes, involving the diminution in the number of aliphatic CH structures, the complete loss of the exocyclic alkene function, the appearance of aromatic structures and the conversion of carboxylic acids to acid anhydrides. Above 250°C, aliphatic groups continued to decline in number, aromatic character continued to increase and spectroscopic features, attributable to acid anhydrides, achieved maximum intensity. The optical reflectance of resinite increased with increasing oxidation temperature and the trends in reflectance and fluorescence properties (colour, wavelength of maximum intensity and red/green quotient) could be ascribed, as reported in earlier studies, to: (1) chemisorption, which occurs between 25° and 100°C, and decomposition of chemisorbed components at 100–150°C; (2) oxycoal formation (150–300°C), in which oxygen complexes and oxidation rims develop; and (3) combustion (>350°C). The variations n mass, infrared peak ratio (CH/C=O), fraction of aromatic carbon (fa) and fraction of hydrogen attached to aromatic carbon (Har), with the variation in the temperature of oxidation mirrored the changes observed by optical microscopy. The results show that the physical changes observed by optical microscopy have a direct correlation with the molecular structural changes determined by FT-IR and NMR spectroscopy. Additionally, it has been observed that resinites underwent thermal aromatization, a phenomenon not well studied for these materials. The changes observed in oxidation structures can be related to reactions involving thermal dehydrogenation of the diterpenoid ring structures and those involving oxygen addition. Oxygen inclusion occurs at all temperatures above 100°C, whereas thermal aromatization occurs mainly above 250°C.

Elliot Lake organic matter falls into two main groups: (1) stratiform kerogens with reflectance from 2.63 to 7.31% Ro(max), exhibit a high level of aromaticity and low atomic H/C ratios (0.41 − 0.60): (2) less aromatic disseminated globules, most resembling solid bitumen are of lower maturity, with Ro(max) from 0.72 to 1.32. and atomic H/C ratios 0.71 − 0.81. Stratiform kerogens, originated from cyanobacteria, have δ13C values from −15 to −25%. One exception with δ13C = − 31.8%, may have originated from methanogenic source biota: thus two genetically distinct populations of kerogen are tentatively recognized in Elliot Lake metasediments. Globular bitumens, remobilized by hydrous pyrolysis from kerogen, exhibit δ13C values ranging from −25% tp −33%0. The overall isotopic bimodality among Elliot Lake organic material is explained by analogy to petroleum generation from particulate kerogen that matured under conditions of catagenesis to metagenesis and was subjected to radiation over a long time. Barium, U, Th, Au, Pt, Pd and REE contents of Elliot Lake stratiform kerogen greatly exceed of average black shales. Except for As, Pt, Pd and Au, all metals (Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Se, Rb, Sr, Ag, Sb, Cs, Ba, Hf, Ta, W, Hg, Th and U) are more concentrated in stratiform kerogens than in the derivative bitumen. This signals a significant role for a low-temperature transfer of noble metals to migrating bitumen.

Approximately 130 core and drillhole cuttings samples taken from the Palaeozoic and Mesozoic of northwestern Melville Island were examined using reflected-light microscopy and Rock-Eval pyrolysis. The Triassic Schei Point marine silty shales, known to be good-quality source rocks in certain parts of the Sverdrup Basin, are dominated by kerogen Types I and II, have hydrogen index (HI) values as high as 625 mg hydrocarbon (HC)/g organic carbon, a total organic carbon (TOC) content as high as 8.07o, but are marginally mature at best. Source potential decreases drastically in the Jurassic and Cretaceous parts of the succession The Palaeozoic section is dominated by bitumen, and often numerous bitumen populations are identified based on morphology, texture, and optical properties. Bitumen reflectance increases with depth, following a trend almost parallel to vitrinite, an indication that it is primary and has been subjected to similar thermal stress. The upper Palaeozoic sediments are within the hydro...

Variations in reflectance and bireflectance of graptolites taken from the Cape Phillips Formation in the Queen Elizabeth Islands, Arctic Canada, are documented. Graptolites taken from core samples from Melville Island possess a wide range of reflectance (1.75–3.90% R0max). Graptolites taken from outcrop samples from the other islands have a much narrower reflectance distribution (0.57–0.81% R0max). The latter indicate that the organic matter is in the mature stage of hydrocarbon generation. Conodont colour-alteration indices in strata from Arctic Canada and in the Cape Phillips Formation in Eldridge Bay E-79, Melville Island, are low (1–1.5) and agree with the low reflectance of the Cape Phillips graptolites. The higher maximum reflectance values of the Melville Island graptolites indicate that the host sediments have experienced deeper burial and exposure to elevated temperatures compared to graptolites in the same formation of other islands. This study demonstrates that graptolite reflectance can delineate, relatively accurately, the thermal conditions that sediments enclosing them have experienced and, when combined with bitumen reflectance and stratigraphic and structural evidence, graptolite reflectance can be useful in assessment of thermal maturity and thickness of eroded section in lower Palaezoic successions.

Coals from western Canada were examined for structural changes occurring during oxidation, carbonization and hydrogenation by means of FT-IR spectroscopy, optical microscopy and chemical analysis. The coals are of Cretaceous to Eocene age, ranging in rank from subbituminous C to medium-volatile bituminous (0.42–1.47% R o ). Results indicate that the reactivity of the coals during the above mentioned processes depends on rank and petrological composition. Infrared spectroscopy is shown to be sensitive to the molecular structural changes occurring during these processes and provides a chemical basis for interpreting data from chemical analysis and optical microscopy.

The thermal maturity and source-rock potential of the Upper Palaeozoic and Mesozoic sediments in the Hecla field, Melville Island, Arctic Canada, have been studied using reflected-light microscopy and Rock-Eval pyrolysis. Approximately 250 polished whole-rock samples were examined and their reflectance (% R 0 , random) measured. In addition, approximately 100 samples were subjected to Rock-Eval/ TOC analyses. Hydrogen-rich organic matter in the Schei Point Group sediments is dominated by alginite ( Tasmanales ), dinoflagellate cysts with minor amounts of sporinite, cutinite, resinite and liptodetrinite in an amorphous fluorescing matrix. Vitrinite reflectance in Cretaceous sediments ranges from 0.41 to 0.54%; in Jurassic sediments it ranges from 0.43 to 0.64% and in Triassic sediments from 0.50 to 0.65%. The Triassic Schei Point Group calcareous shales and marlstones contain organic matter mainly of marine origin, whereas the predominantly terrestially-derived organic matter present in the Jameson Bay (Lower Jurassic) and in the Upper Jurassic to Lower Cretaceous Deer Bay formations have ower TOC . Only the Ringnes Formation has a TOC content of equivalent to or greater than Schei Point source rocks. Within the Schei Point Group, the Cape Richards and Eden Bay members of the Hoyle Bay Formation are slightly richer in TOC than the Murray Harbour Formation (Cape Caledonia Member). Higher average TOC contents (>3.0%) have been reported in the Cape Richards and Eden Bay members in almost all Hecla drillholes. Variations in the level of thermal maturity of Mesozoic sediments in the Hecla field are a function of burial depth. The stratigraphic succession thickens towards the main Sverdrup Basin depocentre located in a N-NE direction. The pattern of the isoreflectance contours at the top of the Triassic (Barrow Formation) is similar to that of formation boundary lines of the same formations, an indication that present-day maturation levels are largely controlled by basin subsidence.

Relationships among organic petrographic maceral assemblages and hydrocarbon source rock depositional environments distinguish broad marine, terrestrial and mixed kerogen accumulation settings. Organic microfacies from Paleozoic and Mesozoic source rock intervals in the intracratonic Williston Basin and the extensional Sverdrup Basin have been studied using incident white and fluorescent light microscopy. Distinct anoxic organic microfacies are defined in Upper Ordovician Bighorn Group subtidal, platformal kukersites and Middle Devonian upper Elk Point Group carbonate lithologies that preserve a progression of depositional environments from platformal to starved basinal. Paleozoic carbonate platform microfacies are characterized by well preserved cyanophyceae alginite stromatolitic mats displaying upper surface textural features such as pustules, pinnacles, endolithic algal borings and interlaminated vertical and horizontal alginite resulting from phototactic growth. Potential source intervals in Middle and Upper Triassic shelf shales from the Sverdrup Basin and Middle Devonian carbonate platform marginal mudstones in the Williston Basin are both characterized by high concentrations of sapropelic, bituminite kerogen hosting unicellular marine alginite. Similar bituminite-rich organic microfacies occur in Middle Devonian basinal settings associated with larger, more abundant alginite and significant amounts of dasycladacean calcareous algae. The main controls on source rock accumulation are water depth and chemistry as controlled by depositional setting and basin restriction.

Five samples from Cretaceous and Jurassic organic-rich shale and coal layers in clastic intervals in the Agur 1 borehole (Negev, southern Israel) were analyzed in order to determine their genetic history, as well as their potential as a source for oil and gas. Analyses of the samples included elemental composition, various pyrolysis experiments and pyrolysis gas chromatography, organic solvent extraction, open-column liquid chromatographic fractionation, saturate fraction gas chromatography and combined gas chromatography-mass spectrometry, and detailed organic petrography using reflected white and fluorescent light microscopy. The results obtained suggest that the Cretaceous sample has a “normal” coaly composition and low maturation in the lignite range whereas the Jurassic samples have unique maceral and geochemical characteristics that reveal evolution through two major stages. In the first stage, terrestrially derived organic material was accumulated under partially oxidizing conditions forming coaly ...

Some of the oldest coals in the world are found within the Middle to Upper Devonian clastic wedge of the Canadian Arctic Archipelago. The coals investigated here occur in the Weatherall, Hecla Bay and Beverly Inlet formations on western Melville Island and range in age from Late Givetian to Middle Frasnian. Many of these coals are rich in liptinite macerals, particularly sporinite and hence can be termed canned coals. Both elemental and Rock-Eval analysis indicate these coals have the potential to generate liquid hydrocarbons. A good correlation between % liptinite with both H/C or Hydrogen Index is observed up to about 50% liptinite after which the latter two parameters level off. The coals range in maturity from 0.61 to 0.87% R o and hence should be in the oil window. The amounts of hydrocarbons that can be extracted from the coals when expressed in mg/g organic carbon are very low, suggesting that they are poor source rocks for oil. All the extracts except for the most mature and vitrinite-rich sample show high pr/ph ratios and biomodal n -alkane distributions. A cannel coal from The Beverley Inlet Formation has a very unusual triterpane distribution that includes regular, AB-ring desmethyl and AB-ring methyl hopanes. Steranes are in very low concentrations compared to hopanes in all samples. The relative abundance of C 28 and C 29 steranes appears to be influenced by maceral composition. Hydrous pyrolysis at 330°C for 72 h generated greater amounts of hydrocarbons from the coals suggesting they could be the source of liquid hydrocarbons at greater maturities. The hydrous pyrolysis experiments also indicate that thin-walled spores are more reactive than thick-walled spores at lower temperatures. The coals on Melville Island are not thought to be significant source rocks for the oil and gas occurrences in this area of the Canadian Arctic because they make up only a very small fraction of the total sedimentary package.

International audience; The Mannville coals in the Fenn area, Alberta Plains, have desorbed gas content averaging 8.57 cm3/g (275 scf/t), which is similar to the same coals in the Corbett Creek area, almost 400 km away. Vitrinite reflectance values are also similar, although the coals at Corbett Creek are situated about 300 m shallower, which points to a rank excursion from Hilt's burial law curves at Corbett Creek. Coals from both areas are within the “oil window”. The Medicine River Seam in the Fenn area has higher total inertinite content and greater proportions of inertodetrinite and detrovitrinite, suggesting that peat deposition occurred in swamps and marshes and were prone to periodic flooding. At Corbett Creek, the Mannville coal seams are characterized by greater concentrations of telo-inertinite, which contributes to coal meso-porosity and the potential for free gas storage in the open cell lumens, and to an increased gas flow along lithotype boundaries (horizontal permeability). Non-fluorescing vitrinite was present mostly in the upper Medicine River Seam, which was deposited in a regressive environment. The lower Medicine River Seam, which formed during a marine transgressive phase, contained greater amounts of fluorescing vitrinite. The Mannville coals in the Fenn area are moderately under-pressured in relation to those at Corbett Creek, which may have an impact on gas retention capacity. The difference in absolute coal permeability (1-3.5 mD at Fenn versus 3-4 mD at Corbett Creek), which is likely the result of higher in-situ stresses in the deeper Mannville coals at Fenn, has had an effect on both gas and water production rates from these coals. However, the largest impact on gas production volumes has been made by the application of horizontal drilling technology, initially at Fenn, and more recently by multiple horizontal wells drilled at Corbett Creek.

The Obed-Marsh coal deposit is of Late Paleocene age, and contains over 200 million tons of subbituminous-B to high-volatile bituminous-C coal. Petrographic analysis of three sections from seams 1 and 2 reveals high amounts of huminite and relatively low amounts of liptinite and inertinite, with the exception of some intervals in both seems. The persistent high ratio of huminite to liptinite and inertinite indicates a relatively reducing environment, a feature also expressed by the relatively low inertinite content. Examination of the in-seam profiles also indicates undisturbed peat accumulation over long periods of time. The Obed coals, similar in rank and composition to the Hat Creek coals of British Columbia, formed in a freshwater environment and can be used as feedstock for combustion/gasification. Furthermore, the intervals rich in liptinite and petroleum-like substances may be utilized for liquefaction (hydrogenation).

Thermally altered pods of coal of very high rank have been observed in a high-volatile-bituminous coal seam in the eastern side of Eagle Mountain, Elk Valley Coalfield, British Columbia. Rank changes have been measured over a strike distance of 7.5 m from 1.24% to 7.1% R o max , corresponding to a rank gradient of 0.78% R o m −1 . Petrologically, unaltered to extremely altered vitrinite showing nongranular (basic) anisotropy, mosaic-textured liptinite and pyrolytic carbon are the most abundant components. The limited presence of mosaic on vitrinite is an indication that the coal seam may have been weathered prior to being heat-affected. Evidence points to localized temperatures as high as 1,000°C, which could have been caused by a lightning strike. The eastern side of Eagle Mountain has experienced higher temperatures than the western side, and it appears that the heat ‘front’ and zone of alteration have an irregular pattern, pointing to saturation of parts of the coal seam by water. Four types of pyrolytic carbon having distinct morphology, anisotrophy and optical path with increasing temperature were observed. Reflectance of pyrolytic carbon falls within the zone of heat-affected coals, whereas the optical path of heat-affected Seam 15 samples is different from that of fresh coal with increasing rank. Finally, the reflectance of vitrinite in heat-affected coal is higher than the reflectance of vitrinite in carbonaceous shale in the Seam 15 section.

This study summarises the rheological behaviour of emulsion bitumen drops in the presence of aqueous solutions of de-ionised or process water (DIW or PW) containing montmorillonite clays (M) and/or calcium ions (Ca++). The presence of calcium ions and montmorillonite clays resulted in the plastic behaviour of bitumen drops. In a DIW+M+Ca++ system, increasing temperature and calcium ion concentration resulted in an increase in the number and degree of plastic bitumen drops. In the presence of considerable amounts of Ca++ ions and/or at higher experimental temperature, bitumen drops in a PW+M system exhibited no significant overall plasticity of their surfaces. Both calcium and sodium ions contained in process water compete with each other to occupy the montmorillonite clay surface. At the pH value of process water (pH congruent with8), increasing the temperature did not change the value of bitumen droplet zeta potential. Stability of bitumen-in-water emulsions at 22 degrees C showed that bitumen droplets coalesced upon contact in the DIW+M system. The addition of calcium ions (Ca++) led to the inhibition of coagulation and coalescence of bitumen droplets, which may indicate the formation of CaM aggregates at the bitumen-water interface.

Mean maximum graptolite reflectance values from numerous sections in Arctic Canada range from 0.6% in Cornwallis Island and northwestern Devon Island to 4.7% in Ellesmere Island. We attribute this great lateral reflectance variation to differing burial depths of the graptolite-bearing strata beneath thick synorogenic siliciclastic covers. We attribute the low maturity of rocks in northern Cornwallis and eastern Bathurst islands to a maximum burial of about 2 km. Elsewhere, we used the paleogeographic location and proximity to the Ellesmerian overthrust wedge to interpret the measured reflectance values. In northern Ellesmere Island, where the highest graptolite reflectance values (4.7%) occur, as much as 9.6 km of synorogenic siliciclastics accumulated on a tectonically loaded carbonate shelf. Initial synorogenic siliciclastics encountered substantial submarine-to-basin relief, and thus about 2 km of sediment were deposited prior to the initiation of deposition on the adjacent drowned shelf. Also, the deep-water sequence probably was underlain by attenuated continental crust adjacent to the southeastward-advancing Ellesmerian overthrust wedge. Together, these factors caused deposition of as much as 7.6 km of sediment in western Melville Island and, as much as 9.6 km in northeastern Ellesmere Island. On the drowned shelf, synorogenic stratal thicknesses were less, a feature we attribu e to a thicker, more rigid crustal sequence and greater distance from the Ellesmerian tectonic loading. We expect liquid hydrocarbons to be generated from the organic matter in the shales in areas with a graptolite R0 maximum (GR0 max) of less than 1.7%. The presence of two types of solid bitumens having different reflectances, morphologies, and optical textures suggests that hydrocarbons were generated and migrated through the graptolite-bearing strata. We expect only gaseous hydrocarbons in areas where GR0 max exceeds 2.0% R0.

The variability in reflectance of huminite (texto-ulminite, eu-ulminite A and B, different types of corpohuminite) and liptinite groups of macerals in subbituminous coals was examined using reflected light microscopy. All macerals were selected from coal and interbedded carbonaceous shale and carbonate sediment samples from the 515-m-thick coal deposit No. 2 located in the Hat Creek valley of south-central British Columbia. The measurements obtained reveal that, in addition to burial depth, reflectance distribution depends on maceral subtypes and associated mineral matrix. Huminite in the coals and sediments (kerogen) consists mainly of humotelinite, with eu-ulminite B being the dominant maceral sub-type. Reflectance values determined on huminite in coals and Type IIIb kerogen increase from eu-ulminite A and phlobaphinite type 1 through eu-ulminite B and phlobaphinite type 2 to gelinite. The reflectance of all five huminite maceral subtypes studied increases with depth. However, the increase of phlobaphinite type 1 and gelinite reflectance with depth is irregular. A comparison of the reflectance values obtained for the same maceral subtype (eu-ulminite B) from the interbedded coal, shale and carbonate samples records consistent differences, implying some dependence of the reflectance (and perhaps rate of organic maturation) on the mineral matrix. Generally, the highest eu-ulminite B reflectance was recorded from carbonate rocks and the lowest from shale, whereas coal matrix produced intermediate values. At present, it is not known whether differences in reflectance of eu-ulminite found in the above lithologies are due to differential retention, efficiency of reaction products removal, thermal conductivity of the lithologies, or existence of a calcium carbonate catalyst.

The present study examines the reflectance and petrology of a self-burning coal wastepile from Coleman, Alberta, Canada. Unaltered coal, carbonization, combustion and ash zones have been identified in the section studied. Due to the presence of uncompacted coal fragments, air can circulate easily through open fractures acting as conduits for convecting gases. Heat generated by the combustion of coal has altered the coal to produce solid (semicoke/coke), liquid (tar) and volatile matter. Several types of tar have been recognized penetrating cracks in the residues, briquetting coal macerals or reacting with coal particles. It has been estimated that the coal was carbonized at a temperature of 500–550°C at a rate of heating of 10°C/min and subsequently combusted at a higher temperature (550–600°C). When comparing the optical and petrological profile of the Coleman self-burning coal wastepile with that of other burning coal seams in Western Canada, certain similarities and differences become apparent.

Summarization: Mineralogical and elemental composition of 26 lignites/lignitic shales and their ashes from the Ioannina Basin were examined using X-ray diffraction, X-ray fluorescence, and instrumental neutron activation analysis. Mineralogy consists of quartz, 2:1 interstratified layer silicates, kaolinite, and gypsum, Illite, calcite, amphi-boles, feldspars, and pyrite are the minor minerals in the samples. The major oxides SiO2, Al203, Fe2O3 TiO2, and K20 show an enrichment in the upper lignite-bearing interval within the succession, CaO shows the exact reverse trend, and Na2O and MgO do not show any trends. Arsenic in the samples ranges from 2 to 46 ppm, Br from 10 to 25 ppm, CI from 61 to 278 ppm, and Se from 2 to 14 ppm. Vertically, As content decreases from the shallower interval II to the deeper interval I. Within interval II, Cr and Br show a decrease from top to bottom. The concentration of Br and CI is higher in the samples of low mineral matter, while the opposite is true for As. Laterally, there is an increase in Br and CI from the northern to the central part of the basin, an increase of As in an eastern direction, and a decrease of Se in the same direction. Epigenetic processes related to high water table and subsurface water flow from the nearby phosphorite deposits are probably responsible for the high concentration of U, Mo, Sb, and possibly, V. The enrichment of Se is due to leaching from gypsum and/or anhydrite beds in the area. The rare earth elements follow variations in the low-temperature ash, but more specifically, the light REEs tend to mimic variations in Th and Al2O3 concentration, and the heavy REEs follow the TiO2 variation. The lignitic ash is “basic” in nature. Ash indices indicate low fouling tendency and low to high slagging potential for the lignites and interbedded lignitic shales, but these indices should be treated with caution. Volatile organic sulfur, determined between ambient and 120°C, is 0-44.3% of the total volatile sulfur, whereas sulfur lost between ambient and 930°C for all samples varies from 19.3% to 93.2%. This is of great importance because of the contribution of volatile sulfur to acid rain formation. Flue gas desulfurizotion and atmospheric fluidized-bed combustion technologies are recommended to meet the stringent sulfur emission control. Presented on: Energy Sources