How did The Pinncales form?

The Pinnacles are a great example of badlands erosion. They are many earth pillars found at the Pinncales. About 7 to 9 million years ago when sea levels were much higher, the Aorangi ranges (where the Pinncales are found) was an island, it was eroded over time and large alluvial fans formed on its southern shores. Within a few million years however, sea levels rose again and the island was submerged as well. Since the Ice ages, sea levels have dropped and the alluvial fans have been exposed erosion, which have weathered away the conglomerate. In some places this conglomerate is protected from erosion above by a cap of cemented silt or rock, resulting in the formation of Pinnacles, many of which have prominent fluting caused by rainwater running down their sides during major storms. It is not known exactly how long the pinnacles have been forming but they are thought to be less than 125,000 years old with major erosion probably beginning 7000 years ago and accelerating in the last 1000 years with the deforestation of the area.

The Pinnacles