ARDROSSAN, large dolomite mining operation owned by Liberty Onesteel to supply flux in their steelmaking process. The quarry developed on a deposit of yellow-brown, fine grained, dense, crystalline, dolomite rock, being a dolomite phase of the basal sequence of the Cambrian Kulpara Limestone. The formation of dolomite may be largely structurally controlled forming in a shallow, S-plunging syncline, with the dolomite distribution bound to the east by the Ardrossan Fault (also the eastern limit of the pit). Within these stuctures the thickness of dolomite exceeds 300m, with the deepest part penetrated to 177m. The dolomite grades lateraly to the west into limestone (also the W limit of the pit). Sandstone, quartzite and grits underlie the dolomite.