Mount Pirongia | |
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![]() Mt. Pirongia, 4 April 2008 | |
Highest point | |
Elevation | 959 m (3,146 ft) |
Coordinates | 37°59′28″S175°05′21″E / 37.991077°S 175.089243°E /-37.991077; 175.089243 |
Dimensions | |
Width | 13 km (8.1 mi)[1] |
Area | 175 km2 (68 sq mi)[1] |
Naming | |
English translation | "Pirongia te aroaro o Kahu" - The scented pathway of Kahu |
Geography | |
![]() Map of selected volcanic features near Mount Pirongia (green marker). In particular the massive debris avalanche towards the south east is well shown. Clicking on the map enlarges it, and enables mouseover of volcano feature/wikilink and ages if available in brackets. The type of basaltic volcanic eruption (some are composite over their eruptive history) is indicated by red being arc basalts, pink being ring basalts of stratovolcanoes and brown being intra-arc basalts typical of those produced bymonogenetic volcanic fields. Approximate location of characterised vents are black rectangles with red centres.[2][3] For wider context see map atNorth Island Surface Volcanism. | |
Location | North Island, New Zealand |
Parent range | Hakarimata Range |
Topo map | NZMS 260 S15 Te Awamutu |
Geology | |
Rock age | latePliocene to earlyPleistocene (2.54–1.6 Ma)[1] |
Mountain type | Stratovolcano (extinct) |
Last eruption | 1.6 million years ago |
Mount Pirongia is anextinctstratovolcano located in theWaikato region of New Zealand'sNorth Island. It rises to 959 m (3,146 ft) and is the highest peak around theWaikato plains. Pirongia's many peaks are basaltic cones created by successive volcanic eruptions between the latePliocene andearly Pleistocene, about 2.5 million years ago.[4] In the adjacent picture, the characteristic profile of the mountain can be seen, along with a prominent accessory cone to the right (on the northern flank).
The Māori people of the Tainui waka (Ngāti Maniapoto, Waikato Tainui, Ngāti Hikairo) have strongwhakapapa-based links to Mount Pirongia. The mountain was first encountered after landfall of theTainui waka around 800 years ago. Early names bestowed on the mountain included Paewhenua (the land barrier, given byRakātaura) 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 fromKahupekapeka (a Tainui tupuna), who following the death of her husband Uenga (descendent of the arikiHoturoa), left Kāwhia with her son Rākamaomao and travelled inland, naming many peaks across the Waikato region.[5] Kahupekapeka searched the bush on Pirongia forrongoā rākau (medicinal plants) to heal her body, which was afflicted by the miscarriage of her unborn child with Uenga.[3]
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 itsecological restoration.[6] During 2001 DoC had invited nominations for a working group. The Society evolved from a hui atPūrekireki Marae on 20 April 2002. The Māori people have a strong connection to Mount Pirongia.[7]
Mount Pirongia is located 20 km (12 mi) to the west ofTe Awamutu and 8 km (5.0 mi) from the small settlement ofPirongia, and lies in thePirongia Forest Park. It is clearly visible from theTasman Sea, being just 25 km (16 mi) from the coast atAotea Harbour.[8]
Mount Pirongia is the largeststratovolcano in theAlexandra Volcanic Group chain which extends inland fromMount 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 theHamilton Basin, a major rift-related depression bound by theWaipa Fault Zone.[2] There are at least six edifice-forming members separated by features including those resulting from large volume collapse events.[3] 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).[9] 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 onKarioi,Kakepuku andTe Kawa but are not found elsewhere in New Zealand.[1]
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 |
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 ofred deer released by farmers after an earlier deer farming boom went bust.[citation needed] Pirongia Forest Park is administered by the WaikatoDoC office in Hamilton.
Threatened plants includeking fern,carmine rātā,thismia rodwayi and Wood Rose orDactylanthus taylorii, a rare and endangered parasitic flowering plant, found on the ridges of Mount Pirongia.[10] Near the summit there are mountain flax, coprosmas and ferns. Botanically, Mount Pirongia is also interesting area as it marks the transition between the warmth-lovingkauri forest of the north and the beech andpodocarp-beech forest in the south. The park's latitude is the naturally occurring southern limit for kauri,mangeao,[11]mairehau,tāwari andtaraire.[10]
Thecanopy in the podocarp forest of the lower slopes istawa, with scatteredrimu,kohekohe and a few other trees. The subcanopy has tree ferns, includingwheki andponga, andnikau palm, withpigeonwood (porokaiwhiri),hīnau,pukatea,supplejack (kareao),māhoe,hangehange,kanono andtoropapa.Rātā replaces kohekohe at higher levels, until a change to upland forest (dominated bykāmahi,tawheowheo and tāwari) at about 650 m (2,130 ft). Above that, kāmahi, tāwari and tawheowheo become more prominent until at 750 m (2,460 ft) tawa is very rare. Above 800 m (2,600 ft) there are also scatteredHall's totara,miro, rātā andhoropito, and, near the summit,pāhautea (at its northern limit on the west coast), but no rimu. Rocky summit pinnacles have the sub alpine speciessnow tōtara and eyebright (Euphrasia revoluta).[10][12]
Commonly found birds are:pīwakawaka,kōtare,tūī,kererū andkārearea.[11] In 2019 funding was won for reintroduction ofkōkako.[13]
Possums andgoats have been controlled since 1996,brown andblack rats since 2006 andmustelids since 2019, using traps and goat, deer and pig hunters.[14] About 1,000 goats were culled in 2021-22.[15]1080 drops in 2007, 2014 and 2020 were effective in reducing possum numbers.[12] ThePirongia-aroaro-o-Kahu Restoration Society has a network ofbait stations on the north east side of Pirongia.[16]
There are numerous tracks to the summit.[17] All the tracks are well signposted, with bright orange plasticwaymarks[18] and near the summit have recently been laid withboardwalks (see photo below), some of them as part ofTe Araroa long distance trail.[19] A lookout platform was built on Pirongia summit after 1999.[7] From it, it is possible to spotMount Taranaki summit andMount Ruapehu summit on a clear day (see sunset photo). On the west side there are Aotea,Kawhia andRaglan harbours.[18]
There are also lower level tracks -
Pirongia was surveyed in 1884, when a very sketchy map was drawn.[32] A trip to the summit fromPirongia (probably now the Wharauroa Route) was described in 1876,[33] was said to be, "not always well marked" in 1879,[34] in 1922 it was reported there were no tracks[35] and, in 1924, that part of the track had become overgrown.[36] Ascents of Pirongia were often reported in newspapers.[37][38][39][40]
Between the Summit and The Cone, at the junction of the Bell and Hihikiwi Tracks, ahut built in 2015 has 20 bunks. An older hut with 6 bunks is next to it.[41]