The geological sequence consists of basement granitoid rocks of the Coast Plutonic Complex of Jurassic-Cretaceous age which are unconformably overlain by the Brown Beds formation a cyclothemic sequence of carbonaceous clays, indurated mudstones, siltstones, shales, conglomerates and minor lignitic coal lenses. It is suggested that these sediments are Late Cretaceous in age. They are confined to a sedimentary basin approximately five kilometres across whose depth has not been determined. The property is known to contain reserves of kaolin and values of gallim and germanium associated with the lignite.