Summary:
The Brule occurrence (Lower Seam adit) is located near the headwaters of Blind Creek about 37 kilometers south of Chetwynd.
The Lower Cretaceous Gething Formation (Bullhead Group) is the main coal-bearing unit at Burnt River and is up to 400 metres thick and consists of interbedded sandstones, siltstones, mudstones, bentonites and semi-anthracite low volatile, low sulphur and high heat value coal. The sediments are generally fine-grained and carbonaceous with some crossbedding and soft sediment deformation structures. The lithologies exhibit extreme thickening and thinning over short distances, and abundant facies changes.
Nine main coal seams occur in the Middle and Upper Gething Formation. They are designated from oldest to youngest: Marker A, A-A, B, Lower seam, Upper seam, Marker C, D, Seam 60 and Marker E. These vary in thickness from 0.5 to 1.5 metres for markers and 0.5 to 11.0 metres for seams. All markers have carbonaceous mudstone, floor and roof, and are predominantly of interest as marker horizons.
The Lower seam is the most consistent with respect to extent and quality. It varies in thickness from 2 to 11 metres and is on average 3.2 metres and 6.2 metres thick in the south and north of the main reserve area, respectively. The seam shows no rock partings except at the southern edge of the property where it is thin with a mineable rock parting. Average ash content is 6.9 per cent, volatile matter is 13.2 per cent, fixed carbon is 79.0 per cent, inherent moisture is 0.9 per cent, sulphur is 0.40 per cent, calorific content of 7910 calories per gram and average thickness of 4.15 metres.
The Upper seam averages 3.2 to 2.8 metres in width and is usually split by a 30 to 60 centimetre shale parting in the north of the deposit. The seam thins and pinches out to the north. The seam is thick and clean in the south where ash levels are 4 to 5 per cent on three metre intercepts. Ash levels increase to 8 to 12 per cent in the north on thinner seams. Average ash is 8.1 per cent, inherent moisture is 0.8 per cent, volatile matter is 13.2 per cent, fixed carbon is 77.9 per cent, sulphur is 0.41 per cent and calorific value of 7800 calories per gram.
The majority of Seam 60 reserves are in the southwest where quality and thickness are consistent. The seam thins and is cleaner to the north. It contains two major high ash zones (25 to 40 per cent ash) and minor rock partings. The lower high ash zone splits the seam in the north. Average seam analysis across 5.87 metres thickness yielded 0.8 per cent inherent moisture, 11.2 per cent ash, 16.1 per cent volatile matter, 71.9 per cent fixed carbon, 0.32 per cent sulphur, and calorific content of 7550 calories per gram.
The structure consists of a series of tight folds and numerous faults. The folds are asymmetrical with northwest-trending axes that plunge to the north or south. Coal seams may have undergone ductile deformation along fold axes. The main reserve area (Brule deposit), is dominated by folds trending northwest and several west dipping thrust faults.
Two regional faults cut the property, the Mount Chamberlain fault in the southwest and the Bullmoose thrust fault east of the Blind Creek syncline. Between these faults, the property is transected by several southwest dipping thrust faults dipping 10 to 40 degrees, which repeat the Lower Gething and Bernot formations across the property.
The Brule deposit is adjacent to and included with the Dillon mine. The much larger Owl syncline contains the Brule deposit. All three seams are represented at Brule.
The Brule deposit is comprised of three LV bituminous coal seams deposited as layers in sedimentary rock formations. The three potentially economic seams are Seam 60, Upper Seam and Lower Seam. The Blind deposit, located to the northeast of the Brule deposit has two inferred and potentially economic seams: the Upper Seam and Lower Seam. The coal seams and sediments were deposited in an inter-fingered and alternating succession of transgressive and regressive cycles along the Western Canadian Sedimentary Basin, and therefore are variable in thickness and coal quality.
Generally for the Brule deposit, the folds trend to the northwest and are open, regular, consistent and predictable. The wavelength of the folds is greater than 1.5 km and the bedding inclinations average around 30º. Six faults have been identified in the area of interest in the Brule deposit. These faults are limited in extent and are generally of reverse orientation.
The Blind deposit is centered on a single northeast-facing steeply dipping anticline limb (monocline). The modeled geological structure, based on drill hole intercepts and surface outcrops, includes a centrally-located drag structure, single reverse orientation fault and minor seam overturn toward the southeast.