Paritu Granite

Paritu granite wharf is made of a coarse grained Miocene era quartz diorite on the coast below the steep slopes of the Moehau Range. The majority of Moehau is heavily forested and considered a biodiversity hot spot. Moehau peak hosts unique flora and fauna for a North Island forest, with a range of native coniferous species such as Halocarpus biformis and Manoao colensoi. It is also the northern limit for many southern species like Phyllocladus alpinus (toatoa) and Libocedrus bidwillii (pahautea). Paritu ‘granite’ forms most of Mt Moehau, this type of rock is rare in the North Island, but common in the South Island which may play into these plant distributions. Its fauna also boasts the rare Archey's frog (whose young hatch from eggs, bypassing the tadpole stage), the Moehau stag beetle, Moehau weta and a population of five-hundred brown kiwi. Potentially a hairy man with large feet also.

Paritu is a sub-volcanic ‘granite’ which formed 16 mya. Technically the rock is not granite, as it varies between quartz diorite, tonalite and granodiorite. These are sub-volcanic, meaning the magma did not make it to the surface and cooled slowly underground, allowing crystals to grow. The stone is still exposed in several of the creek-beds in this vicinity, which Paritu wharf was from built in 1918. This facilitated the export of stone from the district, being used extensively in public monuments and buildings, including Parliament House, Auckland Chief Post Office, Auckland War Memorial Museum, Auckland Ferry Terminal and Auckland Railway Station. The Government owned a quarry reserve of eighty acres, reaching half a mile along the coast-line. Quarrying ended in the 1960s, though in the early 1990s Moehau quarry was reopened for the refurbishment of Parliament House. The rock was popular as it possessed a better rift (break-line) and working qualities than most members of the diorite family, with its effects equal to the best grey granite.

Along the coastline, ancient pōhutukawa of incredible size fall over themselves and each other in a game of botanical twister. A reminder of what the original coastal forest of northern New Zealand would have once looked like. Escaped Agave americana form a strange scene erupting from the rounded stones on shoreline, their flower spikes reaching high into the sky.

Photographs taken on the coarse grained Ilford Delta 3200

References

Classroom interior, School of Mines, Coromandel. Ref: PAColl-5932-25. Alexander Turnbull Library, Wellington, New Zealand. /records/23022193 (image 5)

Garmson, L., n.d. Coromandel Granite. [online] Coromandel Granite. Available at: http://coromandel-granite.weebly.com (image 3&4)

Skinner, D., 1975. Miocene Intrusive Rocks of the Moehau Range, Coromandel. Journal of the Royal Society of New Zealand, 5(3), p.339. (Image 6)