A number of coal zones containing sub-bituminous "B" and "C" rank coal are present in the lower portion of the Fraser River Member of Lower Oligocene Age. The member is greater than 360 metres in thickness and consists of interbedded claystone, sandstone, conglomerate coal and diatomite. Coal seams up to 21.9 metres thick are present in various parts of the Lower Fraser River Unit. The seams contain many claystone partings and both the coal seams and claystone bands are lenticular over short distances. Up to 3 seams are present (e.g. Alexandria Ferry 093B 037) and range from 1.07 metres to 21.9 metres in thickness but are generally less than approximately 3 metres thick. The intervals between the seams vary from 0.46 metres to 141.7 metres.
The coal occurrences are in four main areas: the Red Cliff (093B 055), West Australian Creek and East Australian Creek (093B 010) and Alexandria Ferry (093B 037), all south of Quesnel; in addition to two thick coal seams which outcrop west of Prince George.
The coal contains 3.4 per cent to 45.8 per cent moisture, 23.4 per cent to 52.0 per cent volatile matter, 18.5 per cent to 57.2 per cent fixed carbon, 13.7 per cent to 30.2 per cent ash and 0.23 per cent to 0.6 per cent sulphur.
Resource estimates based on the main coal seams to a depth of 80 metres are 20,984,040 tonnes and 50,020,740 tonnes for areas A and B, west of and including the Australian Creek area, respectively (see Coal Assessment Report #36 for examples). These estimates are based on 1.05 to 1.00 parting to coal ratios, 25 per cent ash in the coal, 50 per cent ash in the partings and flat lying seams.
The strata dips generally less than 35 degrees and commonly less than 20 degrees and are folded into a number of northeast to south- west trending, southwest plunging and west-northwest to east-southeast trending anticlines and synclines. An anticline is present at Australian Creek and a syncline at Dodd's Ranch.