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Western Canadian subbituminous coal is mined using strip-mining methods. The coal is used to feed coal-fired power plants for electricity generation. Parameters that influence the mercury content of these coals include the occurrence and frequency of partings in the seam, weathering, and epigenetic mineralization. Most partings have higher mercury content than the coal layers in the same seam, with the single bentonite bed having the highest Hg content. However, some high ash components, such as sandy siltstone, do not follow this trend. The incorporation of the high mercury partings into the as-mined coal may increase the Hg content in the feed coal. Epigenetic mineralization may also increase the mercury content of coal, depending on the nature of the mineralization. Calculation of the weighted mean of mercury content for various combination of lithological components of a seam illustrates how these components influence the total mercury content of the seam. This approach also suggests how selective mining might be used to reduce mercury in “as-mined” coal. Results of weighted average calculations of mercury indicate that the thin lithological units with moderate mercury may not necessarily influence that overall weighted average of Hg for a seam. However, there can be exception, such as presence of thin (3.5 cm) bentonite parting with high mercury in a 94.5 cm seam that increased the mercury content of seam by 83.4%.

The quantities of six elements (As, Cd, Cu, Hg, Pb, and Zn) were determined in surface soil from 21 stations around the zinc–lead smelter in Trail, British Columbia, Canada. The flux of elements into a unit of soil was then calculated by extrapolating aerial deposition monitoring data obtained from flat square moss bags, which act as traps for airborne particles/elements. The net increase in the quantity of elements in a 10 cm deep by 1 hectare soil unit over a 3-month time interval was estimated as 0.02, 0.65, 0.07, 0.29, 0.22, and 0.65% for As, Cd, Cu, Hg, Pb, and Zn, respectively. The results of this study can be used for elemental inventory of soil in the Trail area and to predict the long-term degree of accumulation of trace elements in the soil. The significant correlation between the deposition rate of Pb, Zn, Cd, and Cu as registered by moss monitoring stations and the quantity of these elements in surface soil indicate the possible effect of airborne material on the geochemistry of the soils in the study area. In contrast, the poor correlation for Hg and As indicates that the variations of these elements in soil samples are likely related to soil chemistry rather than atmospheric deposition. This demonstrates the importance of monitoring for atmospheric deposition of elements since soil is not always a good indicator of the spatial influence of a point source in the study area.

Feed-coals used in some Canadian power plants were examined for their mineralogical and elemental composition. The mode of occurrence of elements (organic/minerals) in these samples were determined using sequential leaching by H 2 O, NH 4 OAc and HCl. Canadian feed-coals examined in this study are subbituminous to bituminous rank (calorific values: 19.62–29.88 MJ/kg). The sulphur content of these coals is 0.32–3.55%. Quartz and aluminosilicates (clay minerals and feldspar) dominate the mineralogy of these samples. The accessory minerals consists of pyrite, sphalerite, barite, calcite, anhydrite, chromite, zircon, biotite, and monazite, which occur as both primary and secondary cell filling types. An interesting mineral found in one of the subbituminous feed-coals is the gorceixite that is normally associated with degraded volcanic ash. The sulphur content of the feed-coals is an indication of their geological setting with feed-coal formed in a fresh water setting containing the least amount of S and those associated with evaporites having the highest S content. The concentrations of Cd, Cr, Cu, Hg, Ni, Se, V, and Zn in these Canadian feed-coals are low compared to world coals. Mercury content of these feed-coals ranges from 0.04 to 0.16 ppm. Mercury is mostly associated with the pyretic portion of coal and has direct correlation to As and S content in these coals. Arsenic in low sulphur coals is mostly associated with coal macerals and in higher sulphur coals with pyrite. About 47% of As in high sulphur coal is removed after leaching by HCl. Water soluble elements consist of Co, Ni and Mn, which are associated only with bituminous feed-coals. The removal of these elements by water is possibly due to an increased acidity of leaching solution and presence of soluble Cl and S. Beryllium and vanadium in low S coals are mostly removed after leaching by HCl, indicating a possible association with clay minerals. Limited Be and V is removed from lower clay mineral content coals; however, in high S content coals, more Be and V are removed. The speciation of As, Cr and Ni indicates that As is mostly present in the less-toxic form As +5 and Cr is present entirely as Cr 3+ , an essential human trace nutrient, found in both subbituminous and bituminous ranked coals. Nickel is present mostly as Ni 2+ in oxygen coordination in these milled coals and carcinogenic compounds of nickel are not present in these feed-coals.

The atmospheric deposition and regional dispersion pattern of the elements As, Cd, Cu, Hg, Pb and Zn, emitted from Pb-Zn smelters at Trail, British Columbia, Canada, were studied for a period of two years using the passive collection moss-monitoring method. Concentrations of these elements in moss bags, exposed to atmospheric deposition for three months, were first corrected for geogenic input and then site-specific local background level to produce common background elemental concentrations for all monitoring stations. The results of this study indicate that the deposition of these elements is greatest in proximity to the smelter and decreases with an increase in distance. The regional dispersion pattern generally varies seasonally, with the magnitude of variation being dependent on the element under study and the location of the monitoring station. Overall, the deposition of these elements (as registered by moss-monitoring stations) appears to be a complex phenomenon involving various factors such as meteorological conditions (prevailing wind direction and precipitation), physiography (topography, valley shape and orientation) and in-process activities at the smelters (production level, emission control efficiency and the geochemistry of feed). However, the results of this study indicate that, on an annual basis, in-process activities, particularly production levels of Pb and Zn and the quantity of emissions from the stack, are more directly related to the observed deposition of the elements than any of the other factors.

The concentration of As, Cr and Ni and their speciation (As3+;5+, Cr3+;6+ and Ni0;2+) in milled coal, bottom ash and ash collected by electrostatic precipitator (ESP) from a coal fired-power plant in western Canada were determined using HGAAS, ICP-AES and XANES. The chemical fractionation of these elements was also determined by a sequential leaching procedure, using deionized water, NH4OAC and HCI as extracting agents. The leachate was analyzed by ICP-AES. Arsenic in the milled coal is mostly associated with organic matter, and 67% of this arsenic is removed by ammonium acetate. This element is totally removed from milled coal after extraction with HCI. Arsenic occurs in both the As3+ and the As5+ oxidation states in the milled coal, while virtually all (>90%) of the arsenic in bottom ash and fly ash appears to be in the less toxic arsenate (As5+) form. Both Ni and Cr in the milled coal are extracted by HCI, indicating that water can mobilize Ni and Cr in an acidic environment. The chromium is leached by water from fly ash as a result of the high pH of the water, which is induced during the leaching. Ammonium acetate removes Ni from bottom ash through an ion exchange process. Chromium in milled coal is present entirely as Cr3+, which is an essential human trace nutrient. The Cr speciation in bottom ash is a more accentuated version of the milled coal and consists mostly of the Cr3+ species. Chromium in fly ash is mostly Cr3+, with significant contamination by stainless-steel from the installation itself.

The geochemistry of Recent sediments from Pigeon Lake, Alberta was studied using Rock-Eval-6 in conjunction with Instrumental Neutron Activation Analyses 137Cs isotope. The results of this study indicate that the variations in Rock-Eval parameters within the sedimentary column are correlated with the concentration of lithophile elements. These variations appear to be controlled by a balance between a number of interrelated processes concerned with both the nature of the deposited biomass and the depositional conditions. Two marker horizons were identified showing an abrupt decrease in Rock-Eval parameters (TOC, S2, and HI) and an increase in concentration of lithophile elements, indicating the clastic nature of the sediments with low autochthonous organic contents. This is attributed to significant natural events such as a storm or flood, which result in a rapid increase in the rate of erosion and subsequently in a high clastic input to the lake. Two cycles showing high organic content were also identified. The first cycle (productivity cycle) corresponds to the increase in algal productivity of the lake due to agricultural activities in the lake’s catchment. In the second cycle (diagenetic cycle), the downward decrease of organic matter is interpreted as the result of selective degradation of organic matter during early diagenesis. The estimated sedimentation rates based on the established marker horizons and 137Cs isotope indicate higher sedimentation in the deeper part of the lake prior to the productivity cycle. However, the sedimentation rates increased towards the littoral zone coinciding with an increase in productivity and subsequently the rise in growth of macrophytes in the near-shore area.

Twenty-five drinking water samples collected from the household property and from the Sydney Regional Municipality well bores and lakes were analyzed to evaluate the various inorganic parameters, level of concentrations of the priority elements and polyaromatic hydrocarbons (PAHs). The pH of the majority of the water samples was below the guidelines adopted by Health and Welfare Canada (1996) , although the drinking waters supplied by the Sydney Regional Municipality were within the guidelines. Only three water samples (13 and 14: Point Aconi area and 16: Port Morien fish plant) have elevated concentrations of various PAHs compared to the detection limit. Eight samples have higher concentrations of manganese and two samples (number 7: Sydney Airport and number 1: RCMP Office; Reserve Mines) have higher concentrations of priority elements (especially lead) than the recommended guidelines (>0.05 mg/l). These priority elements and the PAHs in the drinking water samples may have originated from the leaching of the individual coal seams within that part of the Sydney Basin. Other potential sources of these elements and PAHs (Power Plant disposal, Sydney Tar Pond, metalliferous rocks, hydrocarbon reservoir rocks) are not located close enough to the sampling sites of the water samples. Therefore, they are not considered the source of these elements and PAHs.

Mineralogy and elemental contents were determined on 18 samples from a vertical profile of the No. 2 seam, Genesee mine, AB. The samples analyzed consist of coal, coaly shale, shaly coal, carbonaceous shale, shale, mudstone and siltstone. Proximate analysis was determined on all samples. Elemental analyses were determined by instrumental neutron activation analysis (INAA) for all elements except As, B, Cd, Hg, Mo, Pb, Se (Atomic Absorption) and B, Ba, Be, Co, Cr, Cu, Li, Mn, Nb, Sr and V (inductively coupled plasma-emission spectroscopy, ICP-ES). Samples were low temperature ashed (LTA), X-ray diffraction (XRD) and X-ray fluorescence (XRF) were used to determine quantitative major mineralogy. Accessory mineralogy was determined with Scannining Electron microscope/energy dispersive X-ray analyzer (SEM/EDX) on four samples. In general, the coals in the Genesee mine are within the low end of the range for trace element contents given by Swaine [Swaine, D.J., 1990. Trace Elements in Coal. Butterworths, London, 278 pp.] for most coals. High contents of Cr (9–2620 ppm) and Ni (1–1440 ppm) can be related to an increased amount of a Cr–Ni–Fe oxide (chromite–magnetite?) likely derived from ultrabasic diatremes in the Golden-Columbia Icefields, BC area. The No. 2 seam of the Genesee mine can be divided into two geochemical cycles on the basis of mineralogy, trace element contents and rare earth element (REE) behavior. Cycle I consists of quartz, calcite and kaolinite, lower trace element contents, REE slightly enriched in high rare earth elements (HREE), and thick coal with few partings. Cycle II consists of quartz, calcite, kaolinite, illite, mixed layer and/or expandable lattice clays, feldspar, gypsum, calcium aluminum sulfate hydrate, clinoptilolite, calcite and diopside, higher trace element contents, REE slightly enriched in light rare earth elements (LREE) and thin coal with a greater frequency of partings. The differences between the two geochemical cycles can be accounted for by a decreasing stability of the peat-forming environment resulting from an increasing fluvial influence and volcanogenic input.

This article examines the chemical fractionation (leaching) of elements from the Whitewood Mine subbituminous coals and coal ashes at 120 C, 750 C, and 1000 C. The elements Ba, Zn, and Mn are easily leached from coal by water, ammonium acetate, and hydrochloric acid. Potassium is highly extractable by NH4O acetate but very little with HCl. Hydrochloric acid leaches most of Fe, whereas very small quantities of the element are leached by water or NH4O acetate. Low extractability from coal was noted for Si, Ti, and Cu, an indication of their association with detrital minerals. Extractability of Na from coal was low, which indicates an association with minerals rather than being in the form of exchangeable ions. High leachability for Ca, Sr, and to a certain degree, Mn, Mg, and Na were noted for the 120 C ash samples. Zinc, Ba, S, and P showed a wide variation, reflecting a complex association with carbonate, sulphate, sulphide minerals, and organic matter. Silica, Al, B, Li, Cu, and Mo were completely insolu...

Determining thermal maturity studies in the Ellef Ringnes Island area was complicated by numerous factors, such as the presence of cavings, bitumen staining, and igneous intrusions. Cavings are a problem in certain intervals in Hoodoo H-37, Dome Bay P-36, and Helicopter J-12. Bitumen staining resulting in suppression of reflectance has occurred in the lower part of the Jameson Bay shales in Elve M-40. Thick sills resulted in increase of Ro to 4.0%, whereas thin sills had a minimal impact on reflectance increase. Other features observed include overpressuring caused by hydrocarbon generation in the Schei Point source rocks as well as in the Jameson and Ringnes shales, and a “kinky” Ro profile caused by the presence of low-permeability gas-bearing reservoirs in the Heiberg sandstones in Jackson Bay G-16A. The presence of sapropelic coals with HI up to 329 mg HC/gTOC in Heiberg sandstones in Elve M-40 containing Botryococcus algae should also be noted. Calculated maturation gradients vary from 0.95 ...

The hydrocarbon potential of the Mesozoic succession in the vicinity of King Christian Island in central Sverdrup Basin was evaluated on the basis of maturation parameters and knowledge of the regional geology. The Triassic Schei Point Group, which is the main source rock interval in Sverdrup Basin, is in the mature stage of hydrocarbon generation (Ro>0.60%). The type of organic matter is mainly plank-tonic marine algae and bituminite, deposited in an offshore shelf setting. Rock-Eval Tmax values are in the range 428–444°Q in general agreement with reflectance. Organic richness is indicated by the high hydrogen index (HI) values in the shales (in excess of 300 mg HC/gTOC). Less rich source rocks are found in the Jurassic-age Jameson Bay and Ringnes formations, in accordance with previous studies in the nearby Lougheed and Melville islands. Numerous oil and gas fields have been discovered in King Christian Island to date. Geology shows that the presence or absence of liquid and gaseous hydrocarbon...

Coals and associated carbonaceous strata along the Red Deer River Valley in Alberta have a wide variation in boron concentrations (10--628 ppm). Boron concentrations decrease from bottom to top of the coal-bearing succession, closely reflecting changes in depositional environment conditions. These changes range from subaquatic deposition in the delta plain area and influence of brackish waters due to a marine transgression, to deposition in areas removed from any brackish water influence. There is good agreement between boron variation and depositional environment as interpreted from regional geology. However, the relation between boron and sulfur is not clear; samples with high boron concentrations are high in sulfur while low boron samples also have high sulfur. Compared to mean concentrations in world coals, some of the highest elemental concentrations measured in coals of this study are: As (38.0 ppm), Ba (2800 ppm), Cr (91.0 ppm), Mn (232 ppm), and V (209 ppm). There is a similarity in the vertical variation of the elements Th and Hf, while bentonite layers are enriched in Ba and Sr, pointing to the presence of gorceixite. No enrichment of REEs was observed in the bentonite layers. A comparison of elemental concentration to world mean values for coals showsmore » that the RDRV coals are elevated in As (up to 4{times}), Cr (up to 12 {times}), Mn (up to 4 {times}), Mo (up to 12 {times}), Th (up to 5 {times}), V (up to 12 {times}) and Zn (up to 5 {times}). Compared to coals from the eastern Alberta Plains of similar rank, age, and depositional environment, the RDRV coals have higher or similar concentrations of all elements of environmental significance, with the exception of Be and Pb. When compared to coals of similar rank in the western Alberta plains deposited under freshwater conditions, the RDRV coals have higher concentration of As, B, Ba, Sb, and Sr, similar concentrations of Be, Co, Cu, Mn, Pb, Se, Th, and U, and lower concentrations of Ni.« less

Selected high to medium volatile bituminous coal seams of Carboniferous age from the Sydney and Stellarton Basins, Nova Scotia, Eastern Canada were analyzed for their organic and inorganic components. These studies evaluated: (a) the evolution of the ancestral mires (coal facies) that formed various seams; (b) the lateral and vertical distribution of various elements within coal facies (lithotypes); and (c) the mode of occurrence of various elements. Coal facies fluctuated between rheotrophic and minerotrophic mires with occasional flooding or drowning of the mire forming inorganic partings. These partings are the source for most lithophile elements including B, Cr, U, V, and rare earth elements. Most of the lithophile elements are associated with a distinct, mainly syngenetic, mineral phase (associated with the clay minerals), which is derived from the erosion of a hinterland source. Chlorine, Ca and minor amounts of As and Mn are organically bound. Arsenic is mostly associated with fine-grained framboidal pyrite as solid solution. Other chalcophile elements such as Cu, Pb, and Zn in the Sydney Basin occur as a syngenetic sulfide mineral phase, whereas these elements in the Stellarton Basin are associated with syngenetic and epigenetic sulfides. Arsenic, Cl, and Mo and part of the Cu and Pb are possibly derived from a mineralized brine that was originated from the dissolution of Windsor Group evaporites. The lateral variation of elements suggests that the coal beds in the Sydney Basin are enriched in As, Cl, Mn, and Pb whereas those of the Stellarton Basin are enriched in Cr and Ni. The Donkin resource block of the Sydney Basin has the lowest concentration of As, Mn, Ni, and Pb, which make it attractive from a development perspective.

Organic-rich from the Schei Point group (middle to late Triassic in age) and the Ringnes formation (late Jurassic) from the Sverdrup basin of the Canadian arctic archipelago have been geochemically evaluated for source rock characterization. Most samples from the Schei Point group are organic-rich (> 2% TOC and are considered as immature to mature oil-prone source rocks [kerogen types I, I–II (IIA) and II (IIA)]. These kerogen types contain abundant AOM1, AOM2 and alginite ( Tasmanales, Nostocopsis, Leiosphaeridia , acritarch and dinoflagellate) with variable amounts of vitrinite, inertinite and exinite. Samples from the Ringnes formation contain dominant vitrinite and inertinite with partially oxidized AOM2, alginite and exinite forming mostly immature to mature condensate- and gas-prone source rocks [kerogen type II–III (IIB), III and a few II (IIA)]. Schei Point samples contain higher bitumen extract, saturate hydrocarbons and saturate/ aromatic ratio than the Ringnes samples. Triterpane and sterane (dominant C 30 ) distribution patterns and stable carbon isotope of bitumen and kerogen suggest that the analyzed samples from the Schei Point group are at the onset of oil generation and contain a mixture of sapropelic (algal) and minor terrestrial humic organic matter. Sterane carbon number distributions in the Ringnes formation also suggest a mixed algal and terrestrial organic matter type. There are some variations in hopane carbon number distributions, but these are apparently a function of thermal maturity rather than significant genetic differences among samples. Pyrolysis-gas chromatography/mass spectrometry of the two samples with similar maturity shows that the Schei Point sample generates three times more pyrolyzate than the Ringnes sample. Both samples have a dominant aliphatic character, although the Ringnes sample contains phenol and an aromaticity that is higher than that of the Schei Point sample.

This study reports on the elemental concentrations and vertical variation of coal seams from the Obed Mountain deposit, Alberta Foothills, Canada. Results from two sections of Seam 1 show that the major elements (i.e. Al, Fe, Mg, K, Na, Ti, and Si) have high concentrations in intervals having high ash content, with the only exception of Ca. Similarities are apparent, in both sections, in the vertical variations of Th, U, Se, and Zn; Rb, Cs, and K; Sb, Mo, and W; Mn and Sr; and Ba, Cr, Co, Hf, and Sc. These similarities are also evident among the REEs, notably between Ce and La; also between Dy, Eu, and Sm. Most elements, with the exception of Ba and Sr are slightly more concentrated in Section 2 of Seam 1, located approximately 1.5Fig. km away from Section 1. Compared to Seam 1, Seam 2 has lower mean concentrations of elements. Boron in the coal ranges from 27 to 100 ppmw, though most values are less than 50 ppmw. Boron concentrations suggest a freshwater depositional environment. The element is depleted in the sedimentary partings (12–29 ppmw only) and is enriched in the coal interval near the roof and immediately beneath the partings. This enrichment shows possible downward mobilization of boron. Vertical variations of elements are helpful in delineating the boundaries between coal and sedimentary partings in the succession. The Obed Mountain coals are “clean” by world standards and their elemental concentrations are comparable with those in coals of a lower rank from the same coal formation used for power generation in Alberta. All sedimentary partings have low concentrations of Ba, Hf, Sc, Sr, Ta, Th, U, and REEs; this, along with the absence of an Eu negative anomaly suggests a non-volcanic origin for the partings.

Concentrations of the elements As, B, Br, Cl, Cr, Mn, Na, Sb, Th, U, V, and Zn were determined in ply-by-ply samples from two sections of subbituminous coal from seam 3, Vesta Mine, Alberta Plains. The elemental mean concentrations in section 1 were As l.0 ppm, B 215ppm, Br 2.3ppm, Cl 29ppm, Cr 7.4ppm, Co 1.1 ppm, Mn 24.5 ppm, Mo 2.5 ppm, Na 4900ppm, Sb 0.4 ppm, Se 0.8 ppm, Ti 270 ppm, U 1.4 ppm, Th 2.8 ppm, V 2.9 ppm, and Zn 9.5 ppm. In section 2, the mean concentrations were As 0.7 ppm, B 201 ppm, Br 1.6 ppm, CI 24 ppm, Cr20ppm, Co 1.7 ppm, Mn 30.0ppm, Mo 2.8ppm, Na 4200ppm, Sb 0.3 ppm, Se 0.7ppm, Ti 340ppm, U 0.8 ppm, Th 1.8 ppm, V 4.4 ppm, and Zn 68 ppm. Total sulfur content averaged 0.44% in section 1 and 0.48% in section 2. Mean concentrations of these elements are low when compared to western Canadian coals of similar rank, or to world coals (Swaine, 1990). Antimony, barium, and boron are enriched, with the latter being a reflection of the coal-forming environment. Despite the short lateral distanc...

This preliminary study reports on the concentration of selected elements of environmental concern, such as Be, Cd, F, Hg, Pb, and radionuclides, in subbituminous coals used exclusively for power generation in Alberta. Results show that the concentrations of these elements and radioactive nuclides in the coals studied are low compared to typical concentrations in world coals. The coals are "clean," suitable for use in coal-fired power plants, and their utilization has little impact on the environment. The potential fate of the elements and radionuclides is interpreted only in general terms, mainly by referring to previous studies on the behavior of trace elements and radionuclides during combustion.

The hydrocarbon source rock potential of the Devonian Marcellus and Kettle Point black shales in southern Ontario has been assessed using Rock-Eval pyrolysis, gas chromatography, gas chromatography-mass spectrometry and incident-light microscopy. Both formations contain sufficient hydrogen-rich organic matter (Type II) to be considered possible source rocks. The kerogen is predominantly marine in origin. This organic matter was deposited in a clastic algal-dominated environment, and mainly consists of unstructured bituminite and unicellular alginite. The organic microfacies indicate shelf paleodepositional settings with a transition to an open basinal region. The optical (reflectance, fluorescence) and geochemical (Rock-Eval Tmax, extract yields, distributions of steranes and terpanes) maturity data indicate that the organic matter in the Kettle Point Formation is immature, whereas in the Marcellus Formation it has reached the early stages of hydrocarbon generation and expulsion. Some Devonian oils occurring in this area have characteristics similar to the Marcellus extracts, suggesting that more mature equivalent units from the Appalchian Basin could be their source.

The coal-bearing strata in the Basoren Formation from the Sariz-Karapinar coal region are of middle Miocene age and were deposited in a lacustrine environment. Coal in this formation is lignitic in rank (%Ro, random of eu-ulminite B is 0.37). These lignites have high inertinite content (up to 37.4%), which is higher than in any other Turkish lignites studied previously. Inertinite content in the region increases from the northeast to the southwest, possibly indicating oxidation of organic matter in the coal-forming environment due to lowering of the water level. Total sulfur content in the lignites ranges from 1.8 to 4.8%. High-rank coals present in the Upper Permian Yigiltepe Formation (%Ro, random is 0.66-0.70) contain more sulfur (Stot = 5.6-6.9%) and less inertinite (9.6-12.1%).

Significant oil and gas accumulations occur in and around Lougheed Island, Arctic Canada, where hydrocarbon prospectivity is controlled by potential source rock distribution and composition. The Middle to Upper Triassic rocks of the Schei Point Group (e.g. Murray Harbour and Hoyle Bay formations) contain a mixture of Types I and II organic matter ( Tasmanales marine algae, amorphous fluorescing bituminite). These source rocks are within the oil generation zone and have HI values up to 600 mg HC/g Corg. The younger source rocks of the Lower Jurassic Jameson Bay and the Upper Jurassic Ringnes formations contain mainly gas-prone Type II/III organic matter and are marginally mature. Vitrinite reflectance profiles suggest an effective geothermal gradient essentially similar to the present-day gradient (20 to 30°C/km). Maturation gradients are low, ranging from 0.125 to 0.185 log%Ro/km. Increases in subsidence rate in the Early Cretaceous suggest that the actual heat flow history was variable and has probably diminished from that time. The high deposition rates of the Christopher Formation shales coincide with the main phase of rifting in Aptian-Albian times. Uplift and increased sediment supply in the Maastrichtian resulted in a new sedimentary and tectonic regime, which culminated in the final phase of the Eurekan Orogeny. Burial history models indicate that hydrocarbon generation in the Schei Point Group took place during rifting in Early Cretaceous, long before any Eurekan deformation.

The reflectance of chitinozoa (%ChR0) was investigated as an alternative technique of determining the level of thermal maturity of organic-rich Palaeozoic rocks in southern Ontario. These sedimentary strata, which include the Ordovician Collingwood Member and the Blue Mountain Formation, as well as the Devonian Marcellus Formation, lack vitrinite precluding the application of a standard vitrinite reflectance (%VR0) technique. ChR0 shows a proportional increase at marginal to moderate maturities, being on average 20 to 25% higher than expected vitrinite reflectance. The reflectance data fall into a very narrow range showing a high degree of consistency for each lithostratigraphic unit. The average ChR0 are as follows: Collingwood Mbr 0.63% (Georgian Bay area) and 0.88% (Toronto area), Blue Mountain Fm 0.92%, Marcellus Fm 0.68%. Correlation with more conventional optical and geochemical maturity parameters obtained from the same set of samples (fluorescence of Tasmanites, Leiosphaeridia and Gloeocapsomorpha alginite, Rock-Eval Tmax, extract data, distribution of terpanes and steranes in extracts) indicates that, within the area of study, the beginning of the catagenetic stage corresponds to ChR0=0.65% (equivalent VR=0.50%) whereas the threshold of significant oil generation is reached at ChR0=0.9% (equivalent VR=0.70%). Therefore the Blue Mountain Formation is thermally mature with respect to hydrocarbon generation throughout the whole area of study. The Collingwood shales are mature only in the Toronto area while those occurring in the Georgian Bay area as well as the Marcellus shales have yet to enter the main stage of hydrocarbon generation. This integrated approach of assessing thermal maturity shows that ChR0, when constrained with other maturity parameters, is a very reliable indicator of thermal maturity in Lower to Middle Palaeozoic sedimentary rocks.

A continental minerotrophic peatland in Alberta was studied for its botanical, petrographical, mineralogical and geochemical characteristics. Changes in peat stratigraphy and mineralogy are related, and development toward oligotrophic conditions is recorded. Elemental concentration and distribution vary in the peat profile, reflecting the influence of natural and anthropogenic factors on peat geochemistry. Many elements (Al, As, Ba, Co, Cr, Fe, Mn, Th, V) accumulate in the zone of water table fluctuation as a result of changes in redox chemistry. The relative elemental concentration at the surface and near-surface (e.g., As, Cr, Sb, Th, Ti, V) may also be attributed to atmospheric deposition related to anthropogenic activity. Chemical analysis (Al, Fe, Mg, Na, Si, Ti) also reveals the presence of a non-visible volcanic-ash-rich layer near the base of the peat profile, possibly Mazama tephra. This study provides evidence of pyrite formation in a freshwater peat-forming environment, associated with high-sul...

Results of ash chemistry composition on highwall channel samples, coal seams 1–6, cut W86, Whilewood Mine, reveal that low SiO2 / Al2O2 ratios are associated with high electrostatic precipitator (ESP) opacity. This ratio varies from 2·26 in seam 3 to 5·81 in seam 4, and is a good indicator of the clay minerals present in the coal. A low ratio (

Coal from the deposit of Plakia, Island of Crete, Greece, was examined petrologically for the determination of rank, maceral composition, and trace element geochemistry. The coal is of lignite to subbituminous B rank (%R o,ran = 0.36-0.44). Some samples are rich in resinite. This was subdivided into two groups based on its morphological and fluorescence properties. Mineral matter in the coals consists predominantly of silicate and sulphur-bearing minerals. The low temperature ash (LTA) is dominated by quartz, illite and gypsum, whereas the mineralogy of the high temperature ash (HTA) is comprised of silicates, Fe-bearing minerals and anhydrite. The coals are enriched in the elements As, Cr, Co, Cu, Mn, Mo, Rb, Se, U, V, Ce and Nd, when compared to world coals. Thorium, Zn and most of the REEs are present in concentrations within the mean range for most coals. Bromine, Cl and Se are volatilized at 1000°C, while U, Th, V, Cr, Co, Cu, Mo and Zn are enriched in the coal ash by a factor of 2–8. Also, there are positive correlations among As, Mo, U and S in the coal, as well as between the amount of sulphur-bearing minerals in coal ash and total concentration of As, Mo and U in the coal. Sulphur content in the coals ranges from 3.5% to 5.7%; approximately 4.8–33.6% of sulphur is volatilized at 120°C and a large percentage of total sulphur is volatilized at 1000°C. This has an important implication for the use of the Plakia coals for power generation, because of the emission of SO x compounds to the atmosphere. Fluidized bed combustion and flue gas desulphurization processes are recommended to achieve reduction in trace element and sulphur emissions. The HTA is relatively acidic and the high content of SiO 2 in the ash may create erosion problems in the boilers. Finally, potential problems of slagging and fouling are anticipated, based on the indices (e.g., base-acid ratio) of the lignitic ash.

Subbituminous coals, taken from a freshly mined open pit as well as from nine drillholes in the Whitewood Mine, Alberta, were analyzed for their elemental and radionuclide concentration. Furthermore, the coal ash was analyzed for major oxides, and a comparison was made with coals of similar rank and present only 12 km away, in the Highvale Mine. The Whitewood Mine coals are “clean“ by world standards and do not contain any environmentally deleterious elements in excess amounts. They are suitable for utilization, but care should be taken to minimize the negative opacity effects on the electrostatic precipitators (ESPs). The low Na2O content in the coals, particularly in the open-pit samples, may affect ash resistivity. This could result in a decrease in the flow of current and thus a decrease in the precipitator efficiency. Certain trends of major oxides in the coal ash are observed in a north-south direction and are discussed, with particular emphasis on the Na2O distribution in the six coal seams. The Wh...

Mineralogical analysis of the Highvale Mine coals using X-ray diffraction (XRD) shows quartz, kaolinite, illite, and feldspars to dominate. Minor amounts of carbonate and unknown hydrate minerals are also present, and most minerals reported by XRD have been verified by scanning electron microscopy-energy-dispersive X-ray spectrometry (SEM-EDX) on selected samples using back-scattered electron imaging on coal pellets, The coal ash indices show the Highvale Mine coals to have low to medium propensity to form slagging or fouling deposits in the boilers. The relationship between ash content of mill samples and opacity in the electrostatic precipitators (ESPs) is not clear. However, there appears to be a correspondence between ash resistivity and ESP performance. As resistivity is a function of ash chemical composition, the differences in ash composition, notably in its Fe2O3 content, may have contributed to the increase in opacity recorded for seam 1. The production of submicron particles, via fragme...

This study reports on the enrichment and depletion of elements in selected suites of subbituminous coals from the Highvale Mine, Alberta, Canada and in their 120°C, 400°C and 800°C ashes. All elements analyzed in the raw coal are within the world range for coals and some small variations in elemental concentration were noted due to variations in ash content of the samples. Ashing at 120°C resulted in an enrichment of all elements by a factor of 1.5 × to 6.5 × in one suite of samples and by a factor of 5 × to 11× in the other suite. Generally, the elements Br and Se are enriched by a lower factor than other elements, Mo is absent in all 120°C ashed samples and the samples with the higher ash content show a smaller elemental enrichment than samples with lower ash content (cleaner coals). All elements in the 400°C ashed samples are enriched by a factor of 1.5 × to 6.5 × in one suite of samples and by 1.5 × to 9.5 × in the other. Surprisingly, the elements Br, CI and Se are enriched two- to sixfold, pointing ...

Coals from the Highvale Mine, central Alberta Plains, were studied in order to determine the quantity (range and mean values), affinity, and mode of occurrence of the elements present in these subbituminous coals. Detailed elemental analyses were carried out for all coal seams and interburden in two drillholes, HV901-84 and HV904-84. In total, 49 samples were analyzed from the 16-m-deep HV904-84 drillhole (approximately three samples per meter of succession) and 33 samples from the 10.8-m-deep HV901-84 drillhole (also three samples per meter of succession). Mean concentration of various elements in the highvale Mine coals are as follows, all others are below detection limits: Sb, 0.74 ppm; As, 3.82 ppm; Br, 286.4 ppm; Cl, 72.3 ppm; Cr, 11.5 ppm; Co, 3.25 ppm; Cu, 20.6 ppm; F, 74.3 ppm; Hg, 0.012 ppb, Se, 1.65 ppm; U, 2.57 ppm; Th, 5.6 ppm; and V, 17.1 ppm. by world standards, all mean concentrations, except Br in some instances, are relatively low and the coals are not enriched in any environmentally or industrially hazardous elements. Therefore, the Highvale coals are considered clean by world standards and suitable for utilization. The concentration of elements associated with minerals (clays and/or carbonates), such as K, Mg, Na, Th,more » U, V, and Zn, follows similar repetitive trends within coal seams throughout the coal-bearing succession, indicating that the pattern of coal formation is often cyclic and that these geochemical trends are related to the ash content of the coal and the parting location within the coal-bearing succession.« less

The concentration of boron in Australian and Canadian coals determined using atomic emission spectrometry (AES), inductively coupled plasma spectrometry (ICP-AES) and prompt gamma-ray spectrometry is summarized in order to assess the variation of B content in coal with respect to rank, age, geological setting (in-seam and stratigraphic) and the degree of paleosalinity of the coal-forming environment. This study indicates that no/or very complex relations exist between boron and rank (subbituminous to anthracite). Variations of B with ash content for Canadian coals of different age (Devonian to Oligocene-Eocene) indicate that the B content of coals is not governed by the age of the coal. There is some evidence of variation of B with maceral content in Canadian coals, particularly as related to the inertinite and vitrinite content of coals. The B content of coal seams is sensitive to the environment of deposition, with B contents remaining relatively stable and within the range of values designated for each depositional setting. However, B values may show variation in the same seam laterally due to changes of the environment of deposition and/or the enrichment of B by a secondary source. The vertical variation of B in a coal-bearing section or strata is related to depositional environment and lithology of rock. There is often little variation in B content for coal layers as compared to the partings (dirt bands). The B content of partings in a coal-bearing strata may vary greatly as compared to the coal seams. After reappraising earlier work, and on the basis of more recent studies on Australian and Canadian coals, it is proposed that the following ranges of values for B in coal indicate the degree of marine influence during the early stages of coalification: • up to 50 ppm B: freshwater-influenced coals • 50–110 ppm B: mildly brackish water-influenced coals • >110 ppm B: brackish water-influenced coals. Using these criteria, assessments are given for the degree of marine influence on Canadian and Australian coals.

A suite of liptinite-rich coals from the Lower Cretaceous Mannville Group in the subsurface of Alberta, Canada has been studied with respect to its organic petrology and organic geochemistry. The samples are rich in fluorescing vitrinite (perhydrous), sporinite, cutinite, exsudatinite and bituminite. Rock-Eval analysis shows that the coals are enriched in hydrogen (hydrogen index up to 320 mg HC/g TOC) and depleted in oxygen (oxygen index up to 11 mg CO2/g TOC). The value of Tmax ranges from 445 to 460°C, indicating a late catagenic level of thermal maturity (equivalent to %Ro = 1.0–1.1), but the vitrinite reflectance is between 0.68 and 0.81%, indicating that it is lowered by as much as 0.4%. The pyrolysis chromatograms of the coal samples are dominated by substituted benzenes (toluene and xylenes), naphthalenes, phenanthrenes, substituted phenols (cresols) and small amounts of n-alkanes in the range C20+. Gas chromatography-mass spectrometry of the steranes and terpanes indicates little or no contribution of allochthonous bitumen to the coals. In addition, the mz = 217 sterane traces are dominated by C29 compounds with little C27 and C28; this, along with the high terpane to sterane ratio (mz 191 to mz 217 = 8.8) indicates that the bitumen was generated from terrestrially derived organic matter. The bitumen in the coals has most likely been autogenerated by the coals themselves in response to thermal stress. The originally sapropelic coals were probably deposited in an anaerobic environment and were much enriched in hydrogen. This study shows that terrigenous organic matter, when associated with an anomalous liptinite content, may have the potential to generate bitumen.

Lower Carboniferous (Mississippian) coal beds and oil shale occur at several locations in northern Canada. In the northern Yukon Territory coal of semi-anthracite/anthracite rank ( R 0 max % = 2.72–4.03) occurs in the Kayak Formation in the British Mountains and at Hoidahl Dome near the headwaters of Blow River. Farther south in the Liard Basin, Northwest Territories, coals of high volatile bituminous rank ( R 0 max % = 0.67–0.80) are known to occur in the Mattson Formation. In the Arctic Islands thicker beds of the Emma Fiord Formation, the oldest unit in the Sverdrup Basin, contain thin coal seams and oil shale on Devon Island, near the southern edge of the basin and on Axel Heiberg and Ellesmere islands on the north side of the basin. Organic matter in the Devon Island section is at a low maturity level ( R 0 m % = 0.26–0.50), whereas that from Ellesmere and Axel Heiberg has reached the level of meta-anthracite ( R 0 max % = > 5.0). Depositional environments for these carbonaceous sediments were different. The coal-bearing Kayak strata accumulated in a coastal plain setting overlain transgressively by younger marine beds. The Mattson coal beds appear to have formed in a prograding delta, but coal and oil shale in the Emma Fiord were deposited in lacustrine environments in a rift basin. These Canadian occurrences resemble penecontemporaneous deposits in Svalbard and elsewhere, adjacent to the present-day Arctic Ocean. They formed at low latitudes where conditions were favourable for the preservation of carbonaceous matter. Prior to the opening of the Arctic Ocean basin in Mesozoic times, sites of the mainland were undoubtedly closer to sites in the Arctic Islands than they are today.

The purpose of the study is to better understand the relationship between organic matter optical properties and the presence of potentially large oil and gas accumulations in Arctic Canada. The type and thermal maturity of the dispersed organic matter of the Mesozoic formations in the southern Sverdrup Basin, Melville Island, have been studied using organic petrology and Rock-Eval pyrolysis. All types of organic matter are present in the strata of Mesozoic age. Hydrogen-rich liptinite is dominated by alginite (Botryococcus and Tasmanites), dinoflagellate cysts and amorphous fluorescing matrix. Sporinite, cutinite, resinite and liptodetrinite made up the lesser hydrogen-rich exinite. Vitrinite reflectance in Cretaceous sediments ranges from 0.36 to 0.65% Ro; in Jurassic sediments it ranges from 0.40 to 1.0% Ro and in the Triassic from 0.45 to 1.30% Ro, showing an overall increase with depth of burial. Cretaceous sediments of the Deer Bay Formation are thermally immature and contain organic matter of terrestrial origin. The Upper Jurassic shales of the Ringnes Formation contain predominantly organic matter of liptinitic and exinitic origin with a considerable vitrinitic input. At optimum maturation levels, potential source beds of this formation would have a good hydrocarbon-generating potential. The hydrocarbon potential, however, would be limited to the generation of gases due to the leanness of the source rocks. Parts of the Lower Jurassic Jameson Bay Formation are organic-rich and contain a mixed exinitic/vitrinitic organic matter, Botryococcus colonial algae but visible organic matter is dominated by high plant remains (mainly spores). The Schei Point Group shales and siltstones contain organic matter of almost purely marine origin, whereas the predominantly higher plant-derived organic matter found in the Deer Bay, Jameson Bay and partly in the Ringnes formations have higher TOC. Among the Schei Point Group samples, the Cape Richards and Eden Bay members of the Hoyle Bay Formation are richer in TOC (>2.0%) than the Murray Harbour Formation (Cape Caledonia Member). This may reflect differences in the level of maturity or in the depositional environment (more anoxic conditions for the former). Regional variations in the level of thermal maturity of Mesozoic sediments in Sverdrup Basin appear to be a function of burial depth. The Mesozoic formations thicken towards the basin centre (NNE direction), reflecting the general pattern of increasing thermal maturity north of Sabine Peninsula. However, the regional thermal-maturation pattern of the Mesozoic is not solely a reflection of the present-day geothermal gradient, which indicates that anomalous zones of high geothermal gradient may have existed in the past, at least since when the Mesozoic sediments attained maximum burial depth. The contour pattern of the regional variation of maturity at the base of numerous Triassic formations is similar to that of the structural contours of the Sverdrup Basin, indicating that present-day maturation levels are largely controlled by basin subsidence.

Concentrations of Sb, As, B, Br, Cd, Cl, Cr, Co, Cu, F, Pb, Hg, Mo, Se, Th, U and Zn have been determined in channel samples collected at all active mines in the Peace River (northeastern B.C.) and East Kootenay (southeastern B.C.) coalfields. Means in whole-seam samples from both regions (30 samples), excepting those elements which are below detection limits in some samples, are as follows: Sb 1.0 ppm; As 1.6 ppm; Br 1.0 ppm; Cl 136 ppm; Cr 21 ppm; Co 2.3 ppm; Cu 18 ppm; F 518 ppm; Hg 50 ppb; Th 3.2 ppm; and U 1.8 ppm. By world standards, mean concentrations of Cl, Br, Co, As, Hg and Pb in B.C. coals are relatively low, while concentrations of F are relatively high. Mean values of Cl and Th are statistically higher in Peace River Coals than in East Kootenay coals; concentrations of other elements are similar in the two regions. Consistent stratigraphic variations in the concentrations of elements generally do not occur, although several of the elements, namely Sb, As, Cr, Co, Cu, F, Th aand U, achieve their highest concentrations in the middle one-third of the Mist Mountain Formation (East Kootenay) and in the upper one-half of the Gates Formation coal-bearing section (Peace River). These trends may be more related to variations in ash content of the samples than to stratigraphic controls. Based on correlations, almost all of the eleven elements whose concentrations consistently exceed detection limit appear to have strong inorganic associations. Exceptions are Cl and Br, which appear to be associated predominantly with the organic fraction.

The variation of maturity indicators with respect to mineral matrix and organic matter types was examined from the Mesozoic succession of Melville Island, Arctic Canada. The T max values of non-marine deltaic samples show a much greater degree of scattering with respect to vitrinite reflectance, whereas the marine samples show a narrow distribution. This behaviour is most likely to be a consequence of the differences in the chemical properties of terrestrial versus marine organic matter, which is a function of the organic matter type and of the depositional environment. The non-marine deltaic samples also show higher T max values than their marine counterparts, an indication either of the higher degree of oxidation of the non-marine deltaic samples or of the fact that type III organic matter has intrinsically higher T max values than types I and II organic matter at the same maturity level. Based on the relationship between hydrogen index (HI) and vitrinite reflectance (%Ro), it appears that marine organic matter is more sensitive (high negative correlation) to thermal maturity changes than non-marine deltaic organic matter. No clear correlation between S 2 (hydrocarbon yield) and %Ro (maturity) could be seen in the suite of samples. Both fluorescence parameters ( λ max and R G quotient) increase with maturity but the trends have different slopes for the various macerals, a function of their marine or non-marine origin.

The elemental distribution in peat deposits from Fraser delta, British Columbia, Canada were examined on peat ashed at low temperature (90°C) using INAA, DCP, andAA. Chlorine, B, Br, Mo, Na, S, and U are sensitive indicators of the depositional environment of these peats. The distribution of elements is related to water salinity. High concentrations of Cl and Na are encountered in samples deposited in brackish water environment and in the contact between the peat and the sea water. The concentration of Cl and Na decrease with decreasing distance from the contact with sea water. Silicon has the lowest concentration on the top of the fresh water peat and the highest on or near the top of brackish water peat. The concentration of the “authigenic uranium” in peats appears to be related to water salinity. The highest values are found in brackish water peat, indicating that uranium is possibly concentrated by its interaction with salt and carbonates. Compared to the Clark value, the only elements enric...

Pyrite concentrates were obtained from seven successive coal seams of Upper Carboniferous age in the Sydney Coalfield of Nova Scotia. These concentrates were analyzed for forty-nine trace metals and oxides using INAA and ICPES. The data indicate that trace amounts of other sulphide phases (inclusions as arsenopyrile, galena, chalcopyrite), presumed epigenetic clay minerals, and zircon inclusions are associated with pyrite concentrates. The content of rare earths and actinides in these pyrites are age dependent and tend to be more highly concentrated in the younger seams. Pyritic oxidation in coal and resultant formation and dissolution of secondary sulphate minerals are one mechanism for trace-metal dispersion into the surface-water environment. The pyrite concentrates on average are arsenic-rich (range 240-2900 ppm, mean 1556 ppm). However, this As may form insoluble, stable organic-complexes, which remain as As-rich sediments in situ.

The variation of vitrinite reflectance with respect to mineral matrix (lithology), the thickness of coal seams and coal lenses and the type of organic matter was studied from two cores in a 550 m sedimentary succession from the Upper Jurassic to Lower Cretaceous Kootenay Group. The data obtained indicate that reflectance in high to low volatile bituminous coals (%RO, max = 0.8–1.35) with depth of burial is affected by the percentage of organic matter in the samples. A positive correlation between the vitrinite reflectance and the percentage of organic matter and a negative correlation with the percentage of mineral matter exist and the thicker the coal interval, the higher the vitrinite reflectance. Thick coal seams (>1 m) with a mineral content 20%. Vitrinite dispersed in sandstone and to a lesser extent siltstone and carbonaceous shale has the lowest reflectance. Variations in vitrinite reflectance may be attributed to chemical differences in the organic matter, possibly induced by degradation and diagenesis syn- or post-depositionally, and to the effect of some clay minerals present in the sediments, which may act as catalysts. Differences in the thermal conductivity of the strata have demonstratably not accounted for the observed variations in reflectance with lithology. The differences in the vitrinite reflectance of organic matter between lithotypes is substantial and is thus an important consideration in resolving the time-temperature history and generation of hydrocarbons from a sedimentary succession.

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.

Organic petrology and geochemical studies (Rock-Eval/TOC) were carried out on shales from the Besa River (Upper Devonian-Lower Carboniferous), Yohin, Clausen, Prophet, Golata, and Mattson Formations (Lower Carboniferous) in exposed sequences at Jackfish Gap-Yohin Ridge and in a subsurface section in the North Beaver River area of the Liard Basin. Basinal shales of the Besa River Fm. have TOC values ranging from 1 to 4% and contain abundant type II, dominantly amorphous, kerogen of marine origin. Shales in the Yohin Fm. (slope to neritic shelf), Clausen Fm. (basin and slope deposits), Prophet Fm. (carbonate slope), and Golata Formations are of mixed marine and terrestrial origins and yield TOC values of 1 to 3%

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.

The thermal maturity and source-rock potential of the sedimentary succession in the Drake field, Melville Island, Arctic Canada, have been studied using reflected-light microscopy and Rock-Eval pyrolysis. The Mesozoic sediments are immature to mature (% Ro = 0.35-0.80). Vitrinite reflectance in Cretaceous sediments ranges from 0.35 to 0.56% in Jurassic sediments it ranges from 0.40 to 0.66%, and in Triassic sediments, from 0.50 to 0.80%. The Triassic Schei Point Group shales and siltstones contain organic matter of marine origin, whereas the predominantly plant-derived organic matter present in the Jameson Bay, Ringnes and Deer Bay formations has higher TOC. Among the Schei Point Group sediments, the Eden Bay Member of the Hoyle Bay Formation has high TOC content (approx. 5.0%) and high HI values (in excess of 600 mg HC/gCorg ). It is followed by the Cape Richards Member and the Cape Caledonia Member of the Murray Harbour Formation (approx. 5.0% TOC).

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...

Organic-rich shales are common in the Ringens Formation/Member, an Oxfordian-Kimmeridgian argillaceous unit which is widespread in the Sverdrup Basin of the Canadian Arctic Archipelago. The shales and siltstones of the Ringnes are laminated to burrowed and are interpreted to have been deposited under sub-oxic conditions in a mid to outer shelf setting. The organic matter (OM), which is up to 11 wt%, has relatively low H1 and OI values. Rock-Eval/TOC data, organic petrography and the environment of deposition of the Ringnes, are interpreted to infer that the organic matter in basin margin samples is mainly of terrestrial origin, with a variable but minor marine component. In the axial region of the basin, the OM appears to be of a mixed marine and terrestrial origin and has been partially oxidized. The high organic content is attributed to sedimentation rates high enough to bury the organic-rich sediments before complete destruction by aerobic bacteria and benthic scavengers. The organic content and HI values increase towards the axis of the basin. The thermal maturity of the Ringnes shales varies from immature on the basin margins to mature along the basin axis. In the eastern and central portions of the basin, however, the Ringnes shales are overmature at many localities due to the presence of diabase sills and dykes which were intruded in Early Cretaceous. By contrast, the maturity of the Ringnes is anomalously low over the crests of large salt-cored structures. Rock-Eval/TOC data and petrographic evidence indicate that the Ringnes shales have potential to generate significant amounts of thermogenic gas at low levels of thermal maturity.

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.

Thermally metamorphosed bitumen samples associated with an Archean ultramafic volcanic sequence near Timmins, Ontario, Canada were examined using reflected and transmitted light microscopy and X-ray diffraction. The bitumen occurs in aphanitic to fine-grained chemical and clastic meta-sediments intercalated with the volcanic flows and in derived metasedimentary xenoliths engulfed in the flows. This thermally altered bitumen was apparently derived from biogenic organic carbon in the original Archean sediments. The organic components of the samples consist of epi-impsonite to cata-impsonite and pyrolytic carbons. The latter occur in conical, layered, radial and spherulitic forms. The maximum temperature of formation of the pyrolytic carbon has been estimated at 700°C, which is consistent with its occurrence in xenoliths in these high temperature (1300–1500°C) volcanic flows.

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.