The Haroharo Caldera (Haroharo volcanic complex) is a postulated volcanic feature in

Taupō Volcanic Zone The Taupō Volcanic Zone (TVZ) is a volcanic area in the North Island of New Zealand that has been active for the past two million years and is still highly active. Mount Ruapehu marks its south-western end and the zone runs north-eastward thro ...

of the North Island,

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

within the larger and older Ōkataina Caldera. Since 2010 further studies have tended to use the terms Haroharo vent alignment, Utu Caldera, Matahina Caldera, Rotoiti Caldera and a postulated Kawerau Caldera to the features assigned to it. However the name is used in the peer reviewed literature to summarise these features.

Geography

In the north the Haroharo Caldera extended from the eastern half of Lake Rotoiti to the western border of

Lake Rotoma A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

. Its southern extent was defined by the Tarawera volcano. A recent analysis is consistent with the south western structural boundary being in the eastern portions of Lake Tarawera.

Geology

The Haroharo Caldera is within the older and larger Ōkataina Caldera and its boundaries in geological terms are related mainly to the Matahina and Rotoiti sub-calderas which were formed in single eruption sequences. It is therefore not regarded as a caldera in its own right formed by one single event and there have been many attempts to rationalise the literature. There have been multiple significant eruptions from the Haroharo vent line, that is parallel and to the north of the

Mount Tarawera Mount Tarawera is a volcano on the North Island of New Zealand within the older but volcanically productive Ōkataina Caldera. Located 24 kilometres southeast of Rotorua, it consists of a series of rhyolitic lava domes that were fissu ...

vent line also within the Ōkataina Caldera. There has been a large amount of dome infilling that refer to the name but the Ōkataina complex volcano appears to have emerged as a better name than the Haroharo volcano to understand the processes that have happened in this portion of the Taupō Volcanic Zone. Within the Haroharo vent line there was a VEI-5 volcanic eruption about 6060 BCE producing about of eruptive material and one about 2000 years later that produced of material. Both the Okareka Embayment and the Tarawera Volcanic Complex are adjacent to the Haroharo Caldera which older maps had overlapping the Okataina caldera as part of the Ōkataina volcanic centre Citing and sometimes defined as the Haroharo volcanic complex. With its linear parallel young vent alignment to those of the similarly young in geological terms Tarawera volcano, this means it is now usually regarded as a subsidiary volcanic part of the Ōkataina Caldera which in the last 21,000 years has contributed a total magma eruptive volume greater than about .

References

{{Reflist, 32em Taupō Volcanic Zone Calderas of New Zealand Rift volcanoes Okataina Volcanic Centre VEI-5 volcanoes Holocene calderas