CHRONOLOGY AND DYNAMICS OF A LARGE SILICIC MAGMATIC SYSTEM - CENTRAL TAUPO VOLCANIC ZONE, NEW-ZEALAND

The central Taupo Volcanic Zone in New Zealand is a region of intense Quaternary silicic volcanism accompanying rapid extension of continent al crust. At least 34 caldera-forming ignimbrite eruptions have produc ed a complex sequence of relatively short-lived, nested, and/or overla pping volcanic centers over 1.6 m.y. Silicic volcanism at Taupo is sim ilar to the Yellowstone system in size, longevity, thermal flux, and m agma output rate. However, Taupo contrasts with Yellowstone in the exc eptionally high frequency, but small size, of caldera-forming eruption s. This contrast reflects the thin, rifted nature of the crust, which precludes the development of long-term magmatic cycles at Taupo.