Marokopa Falls

The greywacke rocks that form the waterfall were deposited as sand and mud on the shallow sea floor off the east coast of Gondwana about 180 million years ago during the Jurassic Epoch. At that time Zealandia (New Zealand) was still part of the southern supercontinent of Gondwana and the Tasman Sea had not opened up. These strata belong to what geologists call the Murihiku Terrane and were buried by 2-5 km of additional sediment that compressed and hardened them to greywacke. Before and during the opening of the Tasman Sea (80-55 million years ago) these rocks were further compressed into large folds and pushed up out of the sea as a mountain range. For the next 70-100 million years these mountains were slowly eroded down to a flat coastal plain and eventually submerged beneath shallow seas at the time of maximum submergence of Zealandia during the Oligocene period (33-24 million years ago).
Thick shell banks accumulated on top of the submerged eroded coastal plain and were subsequently hardened into limestone. The flat-lying limestone unconformably overlies the folded underlying greywacke strata and this is known as the Great New Zealand Unconformity as it can be seen in many places around New Zealand.

Can you see limestone rock sitting on top of the greywacke waterfall ? It is now mostly hidden by forest growth.
How did the waterfall form? In the last few million years the local area has been once again uplifted and the Marokopa River is progressively eroding into this uplifted land. The waterfall is gradually advancing back upstream as blocks of greywacke break off along vertical joint plains and are broken up and carried away by the river when in flood. Can you see any large blocks of greywacke rock at the foot of the waterfall or further down the river bed?