The Australian prospect is underlain by Oligocene sediments containing coal measures which were deposited in a basin developed over Paleozoic and Mesozoic rocks of the Intermontane belt during the Tertiary Period. The present distribution of the sediments is mainly confined to the Fraser River valley, where the river has cut down through younger volcanic and sedimentary rocks.
Coal in the Australian Creek area is present in the Lower Fraser River Member (Lower Oligocene) interbedded with claystone, sandstone, and minor conglomerate and diatomite. The coal is sub-bituminous "B" and "C" and contains a number of rock partings and lenses. A coal zone 4.8 metres to 13.2 metres thick was encountered by drilling in the West Australian Creek area. The ratio of coal to total partings varies from 1.0 to 27.50 (average 75 per cent coal, 25 per cent clay partings). Two major coal zones were penetrated in the East Australian Creek area. The zones are 4.2 metres and 21.9 metres thick and also contain numerous clay partings. The coal contains 5.6 per cent to 18.8 per cent moisture, 30.0 per cent to 49.8 per cent volatile matter, 28.4 per cent to 52.2 per cent fixed carbon, 0.6 per cent to 29.4 per cent ash and 1.0 per cent to 1.6 per cent sulphur. The heat value ranges from 15,630 kilojoules per kilogram to 29,215 kilojoules per kilogram.
The structure in the West Australian Creek area consists of a northeast to southwest trending, southwest plunging syncline with dips on the limbs of approximately 10 degrees. Beds dip 15 degrees to 25 degrees northeast in the East Australian Creek area. Exposures on Australian Creek indicate the presence of an anticline with limbs dipping 25 to 45 degrees. A fault zone is postulated to cut through the area.
Reserve estimates are included with the Quesnel coal prospect (093B 036).