Summary:
The southwestern half of the property appears to host generally shallow-dipping strata while a broad, shallow syncline, containing Upper Cretaceous strata of the Dunvegan and Paskapau Formations is shown to be present in the south. A sharp, anticline cored by strata of the Hulcross and Boulder Creek Formations is present in the eastern part of the property. The fold axis of this anticline trends NW-SE and plunges in both directions.
The Gordon Creek area of the Flatbed Property, where the coal resources have been defined, is located along the southwestern limb of the anticline. The strata along the southwestern limb dip approximately 11° towards the southwest. A major high-angle thrust fault bisects the Gordon Creek area.
The thickness of unconsolidated overburden observed in the various drillholes ranges between approximately 11.28m (from drillhole FD17-02) and 92.15m (from drillhole FD17-01). Most of this appears to consist of glacio-fluvial or glacio-lacustrine material. At its contact with the unconsolidated overburden, Shaftesbury Formation lithologies are often weathered and highly broken to semi-coherent for the top 3.05m (FD17-02) to 13.64m (FD17-01).
A total of 8 main coal seams are present within the Gordon Creek area; one minor seam (Seam C) is also present. Seam nomenclature used in this report follows that used currently at the T rend operation and at Babcock. In ascending order, the main seams are labelled as K, J, G, F2, F1, E, D, and B. These seams correlate directly with similarly designated coal seams on adjoining properties.
All seams, except for Seam C, provide potentially mineable coal intervals. Although not considered to be mineable, Seam C can still be traced geologically throughout the deposit. Since it is not considered to hold any economic importance it is not discussed further, herein.
The main characteristics of each of the main coal seams are summarized below. Overall seam thickness ranges for the Gordon Creek area are outlined in Table 7.1; these true thicknesses, sourced from the Norwest coal resource model, were all calculated using a southwest dip of 11°. True thickness ranges and interseam true thicknesses discussed below, are taken from Colonial's exploration drillholes and the two O&G wells while the internal seam characteristics described below, are taken from exploration drillhole FD17-01.
Seam K ranges in true thicknesses from 1.95m (B-30-K) to 3.17m (FD17-01). It is characterized by comparatively clean lower (2.34m) and upper (0.45m) sections separated by a 0.38m claystone band.
Regionally, this seam is often referred to as Seam K1, as there is another coal seam that often sits below K1 that is called K2. In O&G wells B-029-K and B-030-K, Seam K2 is situated approximately 50m below K1. At the Trend mine and on Babcock Mountain, the separation between the two K seams is often less than 10m. Due to drillhole depth limitations, Seam K2 was not penetrated and tested during 2017 to determine if it is of economic interest.
The stratigraphic interval between Seam K and the overlying Seam J, increases northward within the Gordon Creek area, ranging from 22.29m (FD17-01) to 29.48m (B-030-K).
The true thickness of Seam J ranges from 3.38m (FD17-01) to 5.30m (B-30-K). It is characterized by relatively clean lower (1.75m) and upper (1.37m) sections, separated by a carbonaceous rock band that is approximately 0.26m thick.
A thin (0.51m) clean coal split is situated approximately 1.2m above Seam J and is separated from the main seam by a zone of carbonaceous claystone and poor coal bands. This upper section is referred to herein as J upper (JU) as it does not meet the necessary criteria to be included with the main part of the seam for resource determination. It is possible that JU correlates with Seam I at Trend and Babcock.
Within the Gordon Creek area, the stratigraphic interval between Seam J (inclusive of JU) and the overlying Seam G, increases northward, ranging from 21.89m (FD17-01) to 52.27m (B-029-K).
Seam G true thickness ranges from 1.69m (B-029-K) to 3.16m (FD17-01). It is characterized by a thin, relatively clean lower coal section (0.79m) and a thicker (2.04m) upper section, separated by a 0.33m siltstone band. The upper part contains two distinct, thin, poor coal and rock partings.
The stratigraphic interval between Seam G and the overlying Seam F2 decreases northward from 17.48m (FD17-01) to 7.81m (B-029-K).
Seam F2 ranges in true thickness from 2.55m (B-030-K) to 4.49m (FD17-01). It is characterized by a thick (3.46m), relatively clean, lower section with a thinner (1.03m) upper section that contains two thin, poor coal and rock partings.
Seam F2 is separated from the overlying Seam F1 by approximately 0.40m (B-029-K) to 3.46m (FD17-01). This thickness interval decreases towards the northern end of the Gordon Creek deposit, such that the two seams essentially coalesce in B-029-K to form a single, thicker Seam F although, for resource definition purposes, the seams have been picked as F1 and F2. At the adjoining Babcock property, both F1 and F2 are sometimes present, although only one of these seams is present at the equivalent horizon at T rend.
Seam F1 true thickness ranges from 1.28m (B-030-K) to 1.65m (FD17-01). It is characterized by a relatively clean bottom third (0.64m) which contains just one parting of high-ash coal. The rest of the seam (1.01m) contains several thin poor coal and rock partings throughout, the most prominent of which is near the top of the seam. Within the Gordon Creek deposit, Seams F1 and F2, together with the intervening rock band, form a single mining section that is referred to as Zone F.
The separation between Seam F1 and the overlying Seam E increases slightly towards the north, ranging from 7.77m (FD17-01) to 10.65m (B-030-K).
Seam E true thickness ranges from 1.19m (FD17-01) to 1.71m (B-029-K). It is the thinnest of the seams intersected during the 2017 drilling and is characterized by relatively clean lower and upper coal sections (0.63m and 0.38m, respectively) that are separated by a thin (0.18m) poor coal/carbonaceous rock band.
The inter-seam thickness between Seam E and the overlying Seam D decreases significantly towards the north, ranging from 23.41m in FD17-01 to 9.35m in B-030-K.
Seam D true thickness ranges from 2.28m (FD17-01) to 2.65m (B-030-K). The bottom half of the seam contains higher ash coal near the floor while the upper half is characterized by two rock partings ranging between 0.11m and 0.21m in thickness. The roof of this seam is composed of conglomerate.
The inter-seam thickness between Seam D and the overlying Seam B is fairly consistent across the Gordon Creek area, decreasing only slightly northward from 64.95m (FD17-01) to 61.28m (B-029-K).
Seam B is atypical for this region in that this seam has not been reported to reach potentially economic seam thicknesses or be of sufficient coal quality on adjoining projects. At Gordon Creek, Seam B ranges in true thickness from 1.26m (B-029-K) to 3.69m (FD17-03A). The seam contains a number of high-ash coal and rock partings that increase in thickness and frequency upwards. In FD17-01, the roof of this seam is composed of very high ash (stony) coal to very highly carbonaceous claystone; this horizon appears to be replaced by good coal in FD17-03A, to yield a thicker coal seam.