The uppermost rocks are
gravels which are thought to be
Cretaceous in age while the basal shales are thought to be
Permian in age. The majority of the walls appear to be composed of
Triassic and
Jurassic aged sandstones formed under
arid conditions.
Desert roses are also common in the Triassic and Jurassic-aged rocks. The precise geological age of the gorge is unknown, however, the absence of
Early Stone Age occupation in the many caves and shelters in the
gorge suggests that the gorge may be relatively young and have formed in the last 2 million years. ==Flooding==