| Puhipuhi Embayment | |
| Other Name: | Puhipuhi Basin |
| Map: | New Zealand#North Island |
| Elevation M: | 364 |
| Elevation Ref: | [1] |
| Prominence: | Puhipuhi |
| Location: | North Island |
| Country: | New Zealand |
| Region: | Waikato |
| Coordinates: | -38.178°N 176.6076°W |
| Range Coordinates: | -38.177°N 176.6°W |
| Type: | Caldera collapse |
| Width: | 8km (05miles) |
| Volcanic Arc/Belt: | Taupō Rift |
| Volcanic Region: | Taupō Volcanic Zone |
| Last Eruption: | 31,500 ± 5,200 years ago[2] |
| Access: | Restricted |
The Puhipuhi Embayment (also Puhipuhi Basin) is a volcanic feature in Taupo Volcanic Zone of New Zealand associated with the collapse of the Ōkataina Caldera wall to its west.[3] Its latest significant volcanic eruption was about 31,500 years ago[2] and this dating required a reassessment of recent activity at the Eastern extension of the Tarawera vent alignment.[4] [5] [6]
The Puhipuhi Embayment extends from the eastern margin of Mount Tarawera towards Kawerau including land mostly devoted to the Tarawera Forest portion of the Kaingaroa Forest. The basin is a dissected plateau at about 200m (700feet) above sea level.[4] The Tarawera River cuts through the north of the basin and is its drainage.
Both the Pupipuhi Embayment and the Tarawera Volcanic Complex are part of the Ōkataina Volcanic Centre. There is a long eruptive history with the likelihood that some of the 13 Mangaone Subgroup eruptions were from vents in the embayment[7] and the only dacite eruptives from this centre occur in the south of the embayment. Volcanism within and near such collapse structure embayments associated with the volcanic centre is predominately rhyolitic and Matahina ignimbrite is exposed north of the Tarawera River in the embayment, Rotoiti ignimbrite at its southern margins and Kawerau ignimbrite at its centre.[3] The basins Kawerau Ignimbrite is dated to about 31.5 ka[2] and overlies both the much older Matahina ignimbrite (about 280 ka), the relatively recent Rotoiti ignimbrite and also most of the tephras of the 43-31 ka Mangaone Subgroup. Kawerau Ignimbrite is the youngest partially-welded ignimbrite in the Taupō Volcanic Zone.[4] Puhipuhi dacite is found in a small cone and lavas that were intruded in to lake sediments and are usually overlain by Mangaone Subgroup tephras and assigned about 1000 years before the Rotoiti eruption as they are overlaid by this as well.[4] Utu ignimbrites are exposed in small outcrops within the Puhipuhi embayment.[8]
An example of probably basaltic dyke intrusion that never reached the surface, but propagated towards Mount Tarawera, was manifest as an earthquake swarm under the embayment during a recent period of volcanic unrest.[9]