Formation of Caves

Limestone is a sedimentary rock, formed approximately 350 million years ago on the bed of a tropical sea.  The horizontal layers of rock are called bedding planes.   Vertical cracks in the rock caused by huge earth movements are called joints.   Limestone is a permeable, pervious rock because it allows water to pass through it by travelling along the joints and bedding planes.

Rainwater is slightly acidic and slowly dissolves the limestone as it passes through the rock.  This process is called solution.  The joints and bedding planes are slowly enlarged by solution, stream erosion and rock falls to form caves.

	Formation of Caves and Gorges