The Pouākai Range is an eroded and heavily vegetated

stratovolcano A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with ...

in the

North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

, located northwest of

Mount Taranaki Mount Taranaki (), officially Taranaki Maunga and also known as Mount Egmont, is a dormant stratovolcano in the Taranaki region on the west coast of New Zealand's North Island. At , it is the second highest mountain in the North Island, afte ...

. It consists of the remains of a collapsed

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

. The range is surrounded by a ring plain of

lahar A lahar (, from ) is a violent type of mudflow or debris flow composed of a slurry of Pyroclastic rock, pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a valley, river valley. Lahars are o ...

deposits from a massive collapse that has been dated as roughly 250,000 years old. The region has been reshaped more recently after each cone collapse from

Geology

The Pouākai Range volcano is situated in the

Taranaki Basin The Taranaki Basin is an onshore-offshore Cretaceous rift basin on the West Coast of New Zealand. Development of rifting was the result of extensional stresses during the breakup of Gondwanaland. The basin later underwent fore-arc and intra-arc bas ...

and is part of the Taranaki Volcanic Lineament which has had a 30 mm/yr north to south migration over the last 1.75 million years. Present-day seismicity and stress directions in eastern Taranaki are consistent with back-arc extension processes. The Taranaki Volcanic Lineament members as they decrease in age from northwest to southeast are: # Paritutu, and the Sugar Loaf Islands from 1.75 Ma # Kaitake from 575 ka #Pouākai 210–250 ka #

<200 ka

Volcanic activity

"After the extinction of the Kaitake center, eruptions broke out at Pouākai 6 miles south-east of Kaitake. Activity from this center continued over a long period of ring-plain formation, a period of marine erosion during which volcanic activity decreased, and part way through another period of ring-plain building, before activity broke out from the next center." It can be postulated that all volcanoes in the Taranaki Volcanic Lineament have had a similar potential for instability and were stratovolcanoes of similar size and shape to the present Mount Taranaki between major collapse events given their debris plains. They may well have had major collapse cycles similar to that presently shown by

which is a potential maximum size of collapse of every 30,000 to 35,000 years.

Nearby volcanoes

Sugar Loaf Islands The Sugar Loaf Islands (often Sugarloaf; , ) are a collection of five small uninhabited islands and several sea stacks near Port Taranaki, New Zealand. The largest, Moturoa (island), Moturoa Island, covers approximately . Motumahanga is the isla ...

* Kaitake Volcano * Taranaki Volcano

References

{{Egmont National Park Mountain ranges of Taranaki Volcanoes of Taranaki Stratovolcanoes of New Zealand Pleistocene stratovolcanoes Egmont National Park