The geology of the Alpha oil shale deposit

Abstract

Over the past forty-five years a total of 60 holes have been drilled in the vicinity of the Alpha oil shale deposit. This work has delineated an oil shale resource of at least 12 km long and 2.5 km wide. Two types of oil shale occur within the deposit; torbanite and cannel coal. Torbanite has resulted from the accumulation of algal remains and occurs as a lens confined to the northeastern portion of the resource. Cannel coal is more extensive and has resulted from the deposition of terrestrial plant material. The main source of oil in the torbanite is telalginite and oil yields range from 200–622 litres/tonne. Sporinite is the probable main source of oil derived during pyrolysis of the cannel coal which has a range of oil yields from 20–259 dm 3 tonne −1. The deposit contains an in situ inferred resource, Class 2, of between 10–100 million tonnes of oil shale 1. The cannel coal, although yielding less oil than torbanite, is far more extensive and accounts for at least 85 % of the deposit's known shale oil resource.