Putangirua Pinnacles

We revisited the Putangirua Pinnacles because it's such a cool place and we had a day to spare before heading back to Wellington.
The last post of the pinnacles was focused on LOTR so this time there's some geological information:
The Putangirua Pinnacles consist of a large number of earth pillars located in the Aorangi Ranges. About 8 million years ago these ranges were an island. As this landmass was eroded over time, large alluvial fans (triangle-shaped deposits of gravel, sand and smaller pieces of sediment) were formed. Within a few million years the island was yet again submerged by water. Since the ice ages the old alluvial fans have been exposed to the erosive forces of wind and water which have weathered away the conglomerate. In some places this conglomerate is protected from erosion by a cap of cemented silt or rock. This has resulted in the formation of spectacular pinnacles.Read more