History thumb|right|Natural Bridge The area is composed of three major rock types, one of these being gneiss. The oldest of these was formed 1300-1600 million years ago. This rock type can be seen along the cliff walls of the Gap. The granites were formed later as the Australian Plate collided with the Antarctic Plate 1160 million years ago as molten rock rose to the surface. These granites are visible in the tors atop Stony Hill.
History thumb|right|Natural Bridge The area is composed of three major rock types one of these being gneiss The oldest! o:f these was formed 1300-1600 million years ago This rock type can be seen along the cliff walls of the Gap The granites were formed later as the Australian Plate collided with the Antarctic Plate 1160 million years ago as molten rock rose to the surface These granites are visible in the tors atop Stony Hill