Hancox, G.T. 1972 The geology of Pihanga Scenic Reserve. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 133 8 p.
Abstract: The Pihanga Scenic Reserve lies at the southern end of the Taupo Volcanic Zone which extends N.E. from Mt Ruapehu, to White Island in the Bay of Plenty. Most of New Zealand's active volanoes, boiling springs and geysers can be found within this narrow zone which is also characterised by earthquakes and active faulting. The Reserve boundaries encompass most of Mts Pihanga (4348 ft) and Kakaramea (4266 ft), two extinct forest-covered volcanoes at the southern end of Lake Taupo, which together with the national park volcanoes (Ruapehu 9175 ft; Ngauruhoe 7515 ft; and Tongariro 6458 ft), comprises of Tongariro volcanic centre. These andesitic volcanoes are relatively recent geological features and are probably less then 1 million years old. To the east lie the hard ''greywackes'' (sandstones ad mudstones) of the Kaimanawa mountains which, by comparison, are much older (about 150 million years). Similar greywacke type sediments are thought to underlie the volcanic rocks which are almost two miles thick in parts of the Taupo Volcanic Zone. (auth)
