Caldera volcanism and rift structure in the Taupo Volcanic Zone, New Zealand

Abstract

The Taupo Volcanic Zone (TVZ) is an active continental volcanic arc/back-arc basin in central North Island, New Zealand. It is the youngest area of volcanic activity that extends southwards from the Coromandel Volcanic Zone (CVZ), where andesitic volcanism began c. 18 Ma and rhyolitic volcanism c. 10 Ma. It is an extensional basin (average c. 8 mm a 21 ) with numerous, predominantly normal (dip .608) faults within the Taupo Rift, but with some strike-slip component. TVZ can be divided into three parts. In the north (Whakatane Graben -Bay of Plenty) and south (Tongariro volcanic centre) volcanism is predominantly andesitic, while in the central part it is predominantly rhyolitic. This central area comprises eight caldera centres; the oldest of which (Mangakino caldera; 1.62-0.91 Ma) may be transitional between CVZ and TVZ. Kapenga caldera (c. 700 ka) is completely buried by younger volcanics, but is probably a composite structure with most recent subsidence related to volcano-tectonic processes. Of the remaining five caldera centres, Rotorua, Ohakuri and Reporoa are all simple, sub-circular structures which collapsed c. 240 ka, and are each associated with one ignimbrirte outflow sheet (Mamaku, Ohakuri and Kaingaroa, respectively). Okataina and Taupo are caldera complexes with multiple ignimbrite eruptions and phases of collapse. The three simple calderas are extra-rift, occurring outside the main fault zone in the centre of the Taupo Rift system, while the two caldera complexes are both intra-rift. There is a close relationship between volcanism and structure in TVZ, and many of the structural caldera boundaries have rectangular geometry reflecting the fault pattern. Intrusion of high-alumina basalts as dykes, parallel to the fault trend, may have had a strong influence in causing rhyolitic eruptions in central TVZ.

Mechanical and physical properties of hydrothermally altered rocks, Taupo Volcanic Zone, New Zealand

“…1: Wilson et al, 1995;Rowland and Sibson, 2001), and in its modern form coincides with a structurally and magmatically segmented rift system (Taupo rift). The oblique subduction of oceanic crust from the Pacific plate beneath the Indian-Australian plate caused the back arc/arc basin producing the TVZ (Cole, 1990;Bibby et al, 1995Bibby et al, , 2008Darby et al, 2000;Rowland and Sibson, 2004;Cole and Spinks, 2009;Seebeck et al, 2010;.…”

Volcano-structure of El Hierro (Canary Islands)

“…Such maps have already been produced for volcanic areas such as Etna volcano (Sicily, Italy) (Azzarro, Branca, Gwinner, & Coltelli, 2012), Taupo Volcanic Zone (New Zealand) (Cole & Spinks, 2009), TeideCañadas (Tenerife, Canary Islands, Spain) (Galindo, 2005), or La Garrotxa Volcanic Field (Catalonia, Spain) (Bolós et al, 2015). Under the same theme, the study presented here aims at identifying, mapping, and interpreting the main volcano-structural elements of El Hierro (Canary Islands, Spain; Figure 1), in both submarine and subaerial parts of the volcanic edifice.…”

Three-dimensional model of the deep geothermal resources in the Taupo–Reporoa Basin, New Zealand

“…Temperature data given by Leaver (2006) are the inferred average temperatures in the 3 km Wilson et al (1995) and Kissling and Weir (2005). (b) Calderas shown by Kissling and Weir (2005) and Cole and Spinks (2009). Black dashed lines are maximum extent of calderas, black solid lines are possible structural boundaries and purple lines are volcanic centres stated in Kissling and Weir (2005) and within this paper.…”

“…Black dashed lines in these figures show the maximum extent of calderas described by Wilson et al (1995) in Fig. 4a and Cole and Spinks (2009) in Fig. 4b, while the volcanic centre boundaries stated in Kissling and Weir (2005) and used in this modelling study are shown with purple lines in both Fig.…”