Rock around Chillagoe Part 3 – Balancing Rock

Balancing rocks occur in the rocky limestone outcrops, towers, and bluffs of the karst topography around Chillagoe, Queensland, Australia. These geological formations are created by the action of slightly acidic rainwater. This percolates into the cracks, crevices, and fissures of the stratified blocks of resistant stone exposed on the surface by the slow wearing away of overlying burden of sandstone.

The rainwater gradually dissolves the limestone and widens the cracks until individual blocks are formed and left balancing one upon another (Pictures 1 & 2). These features are common in the Chillagoe area but the one actually known as The Balancing Rock is a most spectacular giant monolith that looks as if it could topple over at any minute (Pictures 3 & 4).

A closer look at many of the limestone blocks reveals a surface texturing of parallel grooves or channels with sharp raised edges. These are also caused by slightly acid rainwater as it runs down the face of the stone. The type of erosional feature in these groovy rocks is called Rillenkarren and you can see various examples below in Pictures 5-10.