Mount Pirongia

The Māori people of the Tainui waka (Ngāti Maniapoto, Waikato Tainui, Ngāti Hikairo) have strong whakapapa-based links to Mount Pirongia. The mountain was first encountered after landfall of the Tainui waka around 800 years ago. Early names bestowed on the mountain included Paewhenua (the land barrier, given by Rakātaura) and Pukehoua (now given to a flank cone on the eastern side of the mountain). The present name is:"Te Pirongia o Te Aroaro ō Kahu", which translates to 'the putrid stench of Kahu', or more gently, the 'scented pathway of Kahu'. This name originates from Kahupekapeka (a Tainui tupuna), who following the death of her husband Uenga (descendent of the ariki Hoturoa), left Kāwhia with her son Rākamaomao and travelled inland, naming many peaks across the Waikato region.[4] Kahupekapeka searched the bush on Pirongia for rongoā rākau (medicinal plants) to heal her body, which was afflicted by the miscarriage of her unborn child with Uenga.[5]

To preserve the heritage of Mount Pirongia, Pirongia Te Aroaro o Kahu Restoration Society Inc was formed in 2002 as a result of deep-seated community interest in its ecological restoration.[6] The Māori people have a strong connection to Mount Pirongia.

Mount Pirongia is located 22 kilometres to the west of Te Awamutu and eight kilometres from the small settlement of Pirongia, and lies in the Pirongia Forest Park. It is clearly visible from the Tasman Sea, being just 25 kilometres from the coast at Aotea Harbour.

Geology

Mount Pirongia viewed from a distance (approx Feb 2013); the profile is clearly shown as is the secondary cone to the right of the mountain.

Mount Pirongia is the largest stratovolcano in the Alexandra Volcanic Group chain which extends inland from Mount Karioi near Raglan. It is a mainly basaltic volcano, though andesite dykes form the peaks of Wharauroa, Mahaukura, Tirohanga, Pirongia Summit and The Cone. To the west it merges into the highland terrain of the Karioi horst block and in the east it arises above the Hamilton Basin, a major rift-related depression bound by the Waipa Fault Zone.[7] There are at least six edifice-forming members separated by features including those resulting from large volume collapse events. [5] The largest debris avalanche (the Oparau breccia) cascaded at least 25 km southwest from Pirongia into the Kawhia Harbour and was larger in volume (3.3 km³) than the Mt. St. Helens collapse of 1980 (2.5 km³).[8] The collapse was followed by late-stage eruptions from the summit area around 1.6 Ma. The mountain contains unusually crystal-rich lavas of (ankaramite basalt) that also occur on Karioi, Kakepuku and Te Kawa but are not found elsewhere in New Zealand.[1]

Pirongia event history

Time	Deposit name	Comment
1.60 ± 0.04 Ma	Pirongia	Current summit, also peripheral basaltic eruption 1.64 ± 0.13 Ma on flanks
Approx. 1.65 Ma	Oparau	Collapse volume 3.3 km3 (0.79 cu mi)
Approx. 2 Ma	Hiwikiwi	Collapse and peripheral basaltic eruption 2.03 ± 0.03 Ma
2.25 to 2.13 Ma	Hiwikiwi	2.30 ± 0.005 Ma Hikurangi
2.35 ± 0.2 Ma	Ruapane
2.396 ± 0.005 Ma	Mahaukura	Mahaukura edifice . Central vent is Tirohanga Peak, which is andesitic, as are Mahaukura Bluffs. Ruapane Peak is ankaramite.
2.54 to 2.418	Paewhenua

Land use

River on Pirongia

Mount Pirongia is a popular place for hunters from Hamilton seeking a quick day trip hunt, holding several feral goat herds on its bush-clad slopes. Rumours abound about small numbers of red deer released by farmers after an earlier deer farming boom went bust. Pirongia Forest Park is administered by the Waikato DoC office in Hamilton.

Central plateau from near Pahautea Hut at sunset

Among the variety of plants and wildlife, Wood Rose or Dactylanthus taylorii, a rare and endangered parasitic flowering plant, can be found on the ridges of Mount Pirongia. Variety of podocarps are found at lower altitudes: rimu, totara, tawa and tree ferns. At higher altitudes the forest changes. Hardy plants like horopito and kamahi grow on exposed ridges, and near the summit there are mountain flax, coprosmas and ferns. Commonly found birds are: pīwakawaka, kōtare, tūī, kererū and kārearea. Botanically, Mount Pirongia is also interesting area as it marks the transition between the warmth-loving kauri forest of the north and the beech and podocarp-beech forest in the south. The park's latitude is the naturally occurring southern limit for species such as kauri and mangeao.[9]

View from new hut looking south.

There are numerous tracks to the summit.[10] Mahaukura - Tirohanga Circuit (8–11 hours) is a longer distance but with a gradual climb. This track is well signposted with bright orange plastic markers, but considered difficult. It leads through many steep sections but gives excellent views from Wharauroa lookout, Mahaukura peak (899 m) and Tirohanga peak. In winter and after rain the track becomes muddy and slippery. There are many narrow sections with a tangle of tree roots and rocks. There is a lookout platform on Pirongia summit from where it is possible to spot Mount Taranaki summit and Mount Ruapehu summit on a clear day (see photo below). On the west side there are Kawhia and Raglan harbours.

Boardwalk on Bell Track in pahautea grove. It is gradually being extended towards The Cone.

Between the Summit and The Cone, at the junction of the Bell and Hihikiwi Tracks, a hut built in 2015 has 20 bunks. An older hut with 6 bunks is next to it.[11] Most of the tracks near the summit have recently been laid with boardwalks (see photo below), some of them as part of Te Araroa long distance trail.[12]

• List of volcanoes in New Zealand
• List of mountains of New Zealand by height
• Pirongia Forest Park brochure