The granites of the New England batholith, which formed deep beneath the earth’s surface 270 million years ago, dominate the Park. For the next 50 million years further intrusions of molten rock was forced into fissures deep within the earth’s crust, forming some of the dykes evident in the Park today. Weathering has exposed large granite tors most notably Cathedral Rock, a series of large granite boulders perched one on top of another to a height of about 200 metres and extending approximately one kilometre.
The most recent geological feature in the Park is the basalt capping on the summit of Round Mountain, a domed peak in the centre of the Park. These basalt flows originated in the Ebor volcano, centred to the east of Point Lookout, which was active around 18 million years ago.
The topography of the Park is generally undulating with some rugged granite outcrop areas. The altitude of the Park varies from 1,100m to 1,584 above sea level at the summit of Round Mountain - the highest point on the New England Tablelands.