The Burnt Ridge Extension occurrence is located approximately 9 kilometres northeast of Elkford British Columbia, on the west side of the Fording River, and nearly adjacent to the east of the Greenhills Coal Operations.
Coal seams are interbedded with sandstone, claystone, and siltstone in the Jurassic-Cretaceous Mist Mountain Formation of the Kootenay Group. The Burnt Ridge Extension occurrence is situated on part of the west limb of the northerly trending Alexander Creek syncline. To the west is the northerly trending Erickson normal fault (downfaulted to the east). The eastern limb of the syncline is deformed by the Ewin Pass (or Fording) thrust. Beds strike north and dip east 35 to 65 degrees in the Burnt Ridge Extension area.
Exploration work began at Burnt Ridge Extension around 1969 with geological mapping, test pits, trenches, and adits. Work of mapping, sampling, adit construction, and limited drilling continued through the 1970’s and into the early 1980’s.
Reports written in 1981 and 1982 documented at least 13 coal seams greater than 1 metre thick, making up 12.4 per cent of the section; Seam 1 averages 6.06 metres thick and while being a single seam in the south, consists of a series of splits in the north. Seam 2 is a single seam averaging 3.25 metres, and thins towards the south. Seam 3 averages 3.39 metres and is made up of 2 distinct seams (1 metre split). Seam 4 (6.51 metres) extends the length of the property and in the north contains a 3 metre mudstone split. Seam 5 consists of two seams, a lower (5 metre thick in the north and 1 to 2 metres in the south) and an upper seam (wedges out northward). Average true thickness (composite) is 4.95 metres. Seam 6 is composed of up to 3 major coal splits with an average thickness of 7.47 metres in the south. It does not outcrop in the north. Seam 7 averages 2.97 metres thick, seam 8 is clean and averages 2.57 metres thick, seam 9 averages 4.13 metres and seam 10 is thin (averaging 1.6 metres) and continuous in the south. Seams 11, 12 and 13 are 1.09 metres, 6.79 metres (in a split seam) and 4.65 metres thick respectively (Coal Assessment Reports 376, 377).
The coal which is medium volatile bituminous in rank contains on average 8.2 per cent ash with a Free Swelling Index of 6.4 (1.6 specific gravity float). Volatile matter ranges from 21 to 29 per cent and increases up section. Sulphur contents range from 0.32 to 0.54 per cent for seams 1 to 6, and also show an increase up section (Coal Assessment Report 377).
Open pit reserves were estimated to be 39 million tonnes measured and 24 million tonnes indicated. Underground reserves of seams 1, 4, 6 and 12 (i.e. seams greater than 5 metres thick) were approximately 10 million tonnes to the elevation of Fording River (Coal Assessment Reports 376, 377).
Exploration work continued through the 1980’s by Crow’s Nest Resources Ltd. (Coal Assessment Reports 729, 754). Computer modelling based on previous work was completed in 1991 and produced a resource estimate of approximately 100 million tonnes of coal.
Additional drilling in 1992 and 1996 by Fording Coal Ltd. indicated that 7 major coal seams are present at Burnt Ridge Extension with other transient seams and several minor seams above the 7 seam. 1 seam (010, 012, 011), occurs just above the top of the Morrissey Formation and ranges from 7.16 to 15.9 metres thick. 2 seam (020, 022, 021) occurs roughly 120 metres up section from the top of the Morrissey Formation. 3 seam (030, 031, 032, 034, 036) occurs approximately 180 to 220 metres up section from the top of the Morrissey Formation, and contains 2 to 4 sections of coal, each of which can vary in thickness from 1 to 9 metres. The accumulated thickness of all mineable sections from 3 seam is approximately 12 to 16 metres. 4 seam occurs 130 metres up section from 3 seam and is documented as 2 thin sections 1.20 metres (041), and 1.78 metres (040) thick. 5 seam (050, 051) occurs approximately 360 metres up section from the top of the Morrissey Formation, and its measured aggregate true thickness varies from 3.9 to 5.7 metres. 6 seam (060, 061, 062) occurs approximately 60 metres up section from 5 seam and has a measured true thickness of 4.8 to 9.5 metres. 7 seam (070, 072, 074) occurs approximately 490 metres up section from the top of the Morrissey Formation and has a thickness between 8.14 and 11.98 metres. Coal quality analysis indicates the coal at Burnt Ridge Extension is medium volatile to low volatile bituminous in rank. Vitrinite reflectance values range from 1.37 to 1.02. Sulphur ranges from 0.4 to 0.7 percent. The study notes that the surface oxidized zone is in excess of 20 metres (Coal Assessment Report 852).
The coal deposit at Burnt Ridge Extension is approximately 7.5 kilometres long, covering a 12 square-kilometre area underlain by coal-bearing strata. Based on geological modelling an inferred resource has been calculated at 583 million tonnes of coal (Coal Assessment Report 852).
In 2020, Teck Resources Ltd. reported an updated coal resource for the Cougar and Crow Ridge (MINFILE 082JSE005) deposits with a total of 407 001 000 tonnes of measured and indicated raw coal with an additional 168 540 000 tonnes of indicated raw coal (Mills, D.E., Knight, A.J. [2020-02-20]: NI 43-101 Technical Report on Greenhills Coal Operation, British Columbia, Canada).
