The Pūtangirua Pinnacles, are a geological formation and one of New Zealand’s best examples of badlands erosion, consisting of earth pillars or hoodoos found at head of a valley in the Aorangi Ranges.
It is believed that 7-9 million years ago, when sea levels were much higher, the Aorangi ranges were an island. Over time this landmass was eroded and large alluvial fans formed on its southern shores. Within a few million years sea levels rose again and the island became submerged.
Following the Ice Ages sea levels again receded and the old alluvial fans became hexposed to the erosive forces rain, water, wind which weathered away the conglomerate stomes and silt.
However, in some places this conglomerate was protected from erosion by a cap of cemented silt creating these spectacular pinnacles.
The prominent fluting is caused by rainwater running down their sides during major storms.
The pinnacles are considered to be approximately 125,000 years old – major erosion probably began 7000 years ago and then accelerated in the last 1000 years with the deforestation of the area. Current erosion rate is estimated at about 1 cm per year.
The site has film notoriety, with scenes from the ‘Paths of the Dead’ sequence in ‘The Lord of the Rings: The Return of the King’ filmed on location here. Peter Jackson was returning after filming the opening scenes of ‘Braindead’ a few years earlier.
Text and photos by tim Gruar (tim_gruar@yahoo.com)
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