Reconnaissance of Tikorangi Geothermal Prospect (Haroharo-OkatainaCaldera), New Zealand

Abstract

Geological, geochemical and geophysical reconnaissance surveys of the Tikorangi Geothermal Prospect (previously described as Lake Rotoma Geothermal Field) has shown that a major high temperature hot water system occurs beneath t h e Tikorangi watershed area. system is concealed by young rhyolites of the Haroharo Centre which probably covered the near surface reservoir about 5500 t o 7500 yrs ago. The reservoir can still be recognized from a characteristic magnetic anomaly pattern caused by demagnetized reservoir rocks. water from the upper reservoir drained by a shallow outflow to the north towards Lake Rotoehu and Lake Rotoma, which can by resistivity surveys, There is some for a deeper, almost 8 km long, outflow to the south beneath the Kaipara Stream Both outflows and the resistivity cover of the young any decper resistivity structure ; lateral extent of the reservoir could not be ncd.