Early Jurassic Hedley Intrusions consisting of diorite and gabbro dykes and sills cut limestone, siltstone and argillite of the Upper Triassic Hedley and Stemwinder Mountain formations (Nicola Group). Minor quartz porphyry and andesite dykes cut through all rocks.
The mineralization is described very generally as being tabular in shape with ill-defined walls. The mineralization consists of gold and arsenopyrite in skarn-altered limestone. Good gold values are reported to be associated with gabbro sills.