In form and structure the relief and elevations of the East Bay Hills reflect not only their geological setting, surrounded by rocks of varying resistance, but also their position on the low side of the planation surface. Precambrian rocks of equivalent resistance have created dominant uplands further north in Cape Breton, but here, where there was little uplift during the Tertiary, there was also minimal rejuvenation of erosional action and limited exposure of this hard core of old rocks.