"Mount Somers / Te Kiekie is of volcanic origin, though, as an overlay of the Torlesse Composite Terrane. There are fault lines visible, columns, and cooling fractures."
":Ōkataina Caldera (Ōkataina Volcanic Centre, also spelled Okataina) is a volcanic caldera and its associated volcanoes located in Taupō Volcanic Zone of New Zealand's North Island." "The caldera has seen six eruptions in the past 10,000 years, most recently the 1886 Mount Tarawera eruption in the caldera's southeastern corner. The caldera contains two major lava dome complexes, the Haroharo vent alignment in the north and Tarawera vent alignment in the south. These two vent alignments are associated with current subsidence in the last 20 years of about 1.5 cm/year (0.59 in/year) which is assumed to be because of mainly cooling and contraction of previous magma melt. Other volcanoes connected with the caldera include Putauaki (Mount Edgecumbe) and the maar crater of Lake Rotokawau which is most likely to have formed from a basaltic dike extrusion associated with the common magma mush body."
Dating between 1.7 and 1.74 million years of age, the islands are believed to be the remains of a ring fracture or feeders to eroded volcanic vents.
https://en.wikipedia.org/wiki/Sugar_Loaf_Islands
"The Ohakuri Caldera ( also Ōhakuri Caldera) was formed in a paired single event eruption of Ohakuri ignimbrite and is located in the Taupō Volcanic Zone on the North Island of New Zealand. The paired eruption resulted in a very large eruption sequence in the Taupō Volcanic Zone about 240,000 years ago that included the formation of Lake Rotorua and eruption of the Mamaku ignimbrite."
The paired eruption referred to was a simultaneous eruption of the Ohakuru an Rotorua caldera.
Dacite Dome. Formerly known as Parahaki Dome.
https://www.researchgate.net/publication/37988434_K-Ar_ages_of_Early_Miocene_arc-type_volcanoes_in_northern_New_Zealand
Dating between 1.7[20] and 1.74[21] million years of age, the islands are believed to be the remains of a ring fracture or feeders to eroded volcanic vents
https://en.wikipedia.org/wiki/Sugar_Loaf_Islands
"Pihanga is a 1,326 metres andesitic volcanic peak in the North Island Volcanic Plateau. Eruptions from Pihanga last occurred more than 20,000 years ago. Redating suggests first formation greater than 180,000 years ago."
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