Maroa Caldera | |
---|---|
Highest point | |
Peak | Maroanui |
Elevation | 897 m (2,943 ft) |
Coordinates | 38°31′11″S 176°01′19″E / 38.5198°S 176.022°E |
Dimensions | |
Length | 25 km (16 mi)[1] |
Width | 16 km (9.9 mi)[1] |
Geography | |
Country | New Zealand |
Region | Waikato |
Range coordinates | 38°25′12″S 176°4′48″E / 38.42000°S 176.08000°E |
Geology | |
Age of rock | |
Mountain type | Caldera |
Volcanic region | Taupō Volcanic Zone |
Last eruption | 14,000 years ago[1] |
Climbing | |
Access | State Highway 1 (New Zealand) |
The Maroa Caldera (Maroa Volcanic Centre) is approximately 16 km × 25 km (9.9 mi × 15.5 mi) in size and is located in the north-east corner of the earlier Whakamaru caldera in the Taupō Volcanic Zone in the North Island of New Zealand.
Its northern rim is to the south of the Waikato River at Ātiamuri. At Ātiamuri the Ohakuri Caldera which had a paired eruption with the Rotorua Caldera is to its immediate north. The eastern boundary is also defined by the present Waikato River and it extends as far south as probably opposite Orakei Korako on the river. The southern boundary is somewhat ill defined given the subsequent deep deposits from the Taupō Volcano but includes a number of domes of which the highest is Maroanui at 897 metres (2,943 ft).
The Maroa Caldera's last major eruption produced 140 km3 (33.6 cu mi) of tephra about 230,000 years ago (230 ka).[2] Its earliest eruption was about 300 ka with decreasing frequency and volume to as recently as 11.3 ± 1.7 ka,[3] when an eruption of about 0.25 km3 (0.1 cu mi) occurred from the Puketarata volcanic complex (38°33′02″S 176°03′16″E / 38.550573°S 176.054519°E to distinguish from another older volcano of this name near Te Kawa).[4][5] The caldera is now mainly dome lava in filled.[1] In summary going back in time: [1]