In the Goodrich occurrence area, coal seams occur in the Jurassic-Lower Cretaceous Brenot Formation (Minnes Group) and the Lower Cretaceous Dresser and Gething formations (Bullhead Group), however, the most economic seams are within the Gething Formation.
Coal seams occur in the Upper and Middle Brenot Formation in the north, and in the Middle and Lower Brenot Formation in the south. The coal:rock and coal ratio ranges from 0.04:0.04 metres to 2.18:2.18 metres. The coal is fairly clean with minor rock splits. Seam thicknesses up to 5.52 metres may be a result of fault thickening.
Coal seams occur in the upper part of the Cadomin/Dresser Formation (Bullhead Group), with coal:rock and coal ratios from 0.24:0.70 metres to 2.36:2.88 metres, with seams thickening and becoming cleaner towards the north.
The Gething Formation coal is medium to high volatile bituminous rank (metallurgical quality) and occurs interbedded with mudstones, siltstones, very fine to coarse sandstones and carbonaceous mudstones. The majority of the seams occur in the Upper and Middle Gething, with some in the Lower Gething. The coal:rock and coal ratios average from 0.50:0.50 metres to 4.73:7.19 metres (0.20:020 metres to 3.91:4.12 metres in the north, and 3.08:3.79 metres (true thickness) in a seam on the west limb of the White Rabbit syncline in the White Rabbit Block). At least four upper Gething coal zones are continuous and have an aggregate true thickness of 16 metres over 180 metres.
Potential in-situ resources in the Brenot and Gething formations are estimated (1981) at approximately 1.25 billion tonnes. Two are of open pit potential and are defined by the No. 1 and No. 3 coal seams.
The No. 1 seam (1.14 metres thick in the north and 10 metres thick in the south, averaging approximately 8 metres) contains approximately 80 million tonnes of coal in-place in the Lossan-Axis syncline pair. The No. 3 seam (average thickness 4 metres) contains 20 million tonnes of coal in-place (Coal Assessment Report 532).
The range of approximate analyses on an air dried basis for the Gething No. 1 seam are 11.1 to 16.9 per cent ash, 23.2 to 28.6 per cent volatile matter, 58.6 to 64.5 per cent fixed carbon, 0.2 to 0.28 per cent sulphur and 12,500 to 13,300 BTU per pound.
The structure consists of numerous northwest trending variably plunging folds which are tight towards the west of the property and become more open to the east and northeast. The folds are cut by numerous predominantly northwest trending (some north-northwest trending), southwest dipping thrust faults and a small number of northwest trending normal faults (i.e. Burnt Normal fault). Fewer thrust faults are present in the northeast of the property.
Potentially surface mineable coal estimated from two of four seams within the upper Gething Formation total 100 million tonnes (Coal Assessment Report 532, page 1).
First Coal Corporation is expected to produce 1.5 million tonnes of metallurgical coal per year for export over a mine life of 12 to 13 years.
