Inception of the modern North Island (New Zealand) volcanic setting: spatio-temporal patterns of volcanism between 3.0 and 0.9 Ma

Abstract

ABSTRACT The modern active volcanic setting of the North Island, New Zealand, includes arc volcanism at the young Taupo Volcanic Zone (< 350\u2005ka) and intraplate basaltic volcanism at the Auckland Volcanic Field (< 200\u2005ka). These volcanic settings are markedly different in character and origin, however, the geographic position of the arc volcanoes and intraplate fields have migrated almost in unison across the western North Island over the last three million years. This article reviews the characteristics and volcanic histories of central North Island volcanic centres and fields that were active from 3.0 to 0.9 Ma, including: the silicic Tauranga and Mangakino volcanic centres; the andesitic Pureora, Titiraupenga and Maungatautari stratovolcanoes; the basaltic Alexandra Volcanic Group, which comprises a chain of stratovolcanoes and an interspersed (Okete) volcanic field; and the basaltic Ngatutura and South Auckland volcanic fields. New U-Pb zircon and (U-Th)/He zircon ages for rhyolites and one ignimbrite in the Tauranga Volcanic Centre adds to and confirms the existing dates, as well as confirming the overall age range for this centre. Synchronous volcanism at the Tauranga Volcanic Centre and the Alexandra Volcanic Group is a historic marker for the origin of the modern arc and intraplate settings.