"The volcano is constructed atop an upfaulted block of Mesozoic marine sediments. The age of the erupted lava near the youngest cone is about 900,000 years, making Hauhungatahi more than three times as old as the neighbouring Ruapehu. The oldest rocks sampled have not given definite ages but are possibly up to 1.2 million years old."
"Herbert Peak Hawaiite (8.5 – 8.0 Ma)
After a period of quiescence, volcanic activity shifted from Lyttelton Volcano to the Mt
Herbert region . During this period, there was deep erosion in the
crater, with breaches in the southeast, and possibly, southwest crater rim and slopes of
the Lyttelton Volcano edifice. The Mt Herbert Volcanic Group (9.7 – 8.0 Ma)
initially began from vents in the Lyttelton crater and then migrated south-eastwards to
the crater rim breach, erupting ~100km 3 of material.
Lava erupted from a vent 50 m southeast of Mt Herbert, producing flat lying, columnar to
tabular jointed, grey aphyric to phyric hawaiites that cap Mt Bradley and Mt Herbert
dipping to the north at 2° noted low ash abundance,
indicating activity was dominantly of Hawaiian-type, from a fissure vent eruption. The
characteristic thick columnar jointed flows is linked to extrusion of lavas onto an almost
flat lying surface"
Hampton, S. J. (2010) https://ir.canterbury.ac.nz/handle/10092/4117 p13
Kaikohe Hill is a basaltic scoria cone in the southern part of the Kaikohe-Bay of Islands volcanic field
"In the last half-million years, 12 small basalt volcanoes have erupted in the southern part of the field (Smith
et al. 1993), forming a cluster of scoria cones around Kaikohe. Te Puke volcano erupted in the hills
behind Waitangi 100 000 years ago, forming three small cones and a spreading flow that now underlies
Waitangi golf course and treaty grounds. The youngest volcano is Tauanui, 10 km south of Kaikohe, which
60 000 years ago produced a high scoria cone and a lava flow that flowed 19 km down the Taheke Valley
towards the Hokianga Harbour. The field includes a small rhyolite dome (Putahi), overlooking Lake
Omapere. The field should still be considered dormant, and not extinct."
"The Kaitake Range, like the neighbouring Pouakai Range, is an eroded and heavily vegetated stratovolcano that formed during the Pleistocene epoch in the Taranaki region of New Zealand. Kaitake is the northwesternmost of the stratovolcanoes in the region. It is about 500,000 years old and last erupted around 350,000 years ago. Its final collapse about 250,000 years ago appears to have been potentially associated with a collapse event of the Pouakai volcano. "
https://en.wikipedia.org/wiki/Kaitake_Range
"The Kakaramea-Tihia Massif is an andesitic volcano in the central North Island of New Zealand. It extends from the peak of Kakaramea at 1,300 metres in the west to the peak of Tinui at 1,169 metres. Eruptions from the Kakaramea-Tihia Massif commenced at 229,000 ± 1,000 years ago. A more recent dated eruption was from Tihia, at 198,000 ± 23,000 years ago."
"Kakepuku (449 m asl) is a basaltic dome volcano located at the eastern edge of the Alexandra Volcanic Group, a Plio-Pleistocene volcanic field stretching from Waikeria to the Whāingaroa-Karioi area. Alongside Te Kawa, the Kakepuku dome was constructed during two distinct stages of eruptions at 2.7 and 2.3 million years ago"
"Karioi or Mount Karioi is a 2.4 million year old extinct stratovolcano 8 km (5.0 mi) SW of Raglan in the Waikato region of New Zealand's North Island. It was the earliest of the line of 6 calcalkalic volcanoes, the largest of which is Mount Pirongia (the others are at Kakepuku, Te Kawa, Tokanui, Waikeria and probably Puketotara)."
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