Figure 33.1

Classification of coals by rank and indices of organic maturity. The chart is a composite modified from ASTM (1981), Teichmüller and Teichmüller (in Stach et al., 1982), Dow (1977) and Cameron (1989).

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Figure 33.2

Coalfields of the Western Canada Sedimentary Basin coded according to the lithostratigraphic group or formation within which they occur. The stratigraphic columns highlight the major coal-bearing units by region in the lithostratigraphic context of: a. the Rocky Mountain Front Ranges and Foothills of southwestern Alberta and southeastern British Columbia; b. the Rocky Mountain Foothills of northeastern British Columbia; c. the Rocky Mountain Foothills of west-central Alberta; d. the Interior Plains of south-central Alberta; and e. the Interior Plains of southern Alberta and Saskatchewan.

Figure 33.3

Schematic cross section illustrating the stratigraphic relations of coal-bearing units in the Rocky Mountain Front Ranges and Foothills (after Stott, 1984; Langenberg and McMechan, 1985).

Figure 33.4

Schematic cross section illustrating the correlation and stratigraphic relations of major coal-bearing units in the Interior Plains.

Figure 33.5

Tectonically thickened coal, resulting from cataclastic flow from the limbs into the hinge area of a major structure, Front Ranges of southwest Alberta.

Figure 33.6

Tectonically thickened coal,resulting from imbrication, outer foothills of west-central Alberta.

Figure 33.7

Flat-lying lowermost Edmonton Group, Interior Plains, central Alberta.

Figure 33.8

Near-surface strata deformed by overriding glacial movement, Interior Plains, south-central Alberta.

Figure 33.9

Fault in the Ravenscrag Formation caused by dissolution of underlying salt deposits, Interior Plains, southeastern Saskatchewan.

Figure 33.10

Ternary diagrams showing proportional distribution of vitrinite, inertinite and liptinite maceral groups in coals of the Western Canada Sedimentary Basin. Reflectance histograms show distribution of measured values of % mean vitrinite reflectance for corresponding coals. All reflectances are random, either measured directly or calculated from maximum reflectances according to the formula = /1.066. Rank/reflectance thresholds are according to Figure 33.1. For lower rank coals (e.g., Horseshoe Canyon) the data are plotted in smaller reflectance classes (0.10%Ro) than is the case for the higher rank coals (e.g., Mist Mountain). Although Figure 33.1 shows a tentative reflectance threshold between subbituminous and high volatile bituminous at 0.50%Ro, the boundary is most likely between 0.50 and 0.60%Ro. That is why in histograms such as the Belly River, containing the reflectance class 0.50 - 0.59%, the class has been arbitrarily halved, with one part coded subbituminous and the other high volatile bituminous. The minimum reflectance values are 0.75% for the Mist Mountain Formation (a), 0.76% for the Gething Formation (b), and 1.00%for the Gates Formation (c). Note that the ternary diagram for the Ravenscrag Formation (h) shows huminite maceral group instead of vitrinite.

Figure 33.11

Isomaturity map of Portlandian and Neocomian strata. Data are mainly from the Kootenay and Minnes groups and the Nikanassin Formation. Contours are in % . Points of control data are not shown where contours are shown approximately restored to pre-deformational position (Bustin, 1991).

Figure 33.12

Isomaturity map of Albian strata. Data are from the Blairmore, Luscar and Mannville groups and the Gates and Spirit River formations (Bustin, 1991). Contours are in % . The 0.30 and 0.40% contours are modified from Ozadetz et al. (1990).

Figure 33.13

Isomaturity map of Campanian and Maastrichtian strata. Data are mainly from the Belly River and Edmonton groups. Contours are in % (Bustin, 1991).

Figure 33.14

Isomaturity map of surface exposures in the Western Canada Sedimentary Basin. Contours are in % . Lines of cross section are for Figures 33.16 and 33.17.

Figure 33.15

Inferred thickness of eroded overburden in the Western Canada Sedimentary Basin based on extrapolating measured maturation gradients to 0.25%and utilizing surface maturity values. The map is highly schematic and generalized, and no attempt has been made to honour local variations in maturation gradient (Bustin, 1991).

Figure 33.16

Cross section A-A' showing isomaturity lines and approximate position of oil window. Oil window is defined as between 0.55 and 1.35% . Cross section location is shown on Figure 33.14 (Bustin, 1991).

Figure 33.17

Cross section B-B' showing isomaturity line and approximate position of oil window. Oil window is defined as between 0.55 and 1.35% . Cross section location is shown on Figure 33.14 (Bustin, 1991).

Figure 33.18

Summary of estimated coal resource quantities in the Western Canada Sedimentary Basin. All figures are in million metric tonnes (megatonnes). Figures in brackets are estimates on a tonnes coal equivalent basis, which refers unit heat values of different coals to a standard 29.3 MJ/kg.