This paper combines some of the results and interpretations of geological mapping, seismic refraction, marine seismic, and gravity surveys to show that large tracts of New Britain could be favorable targets for geothermal power development. It is shown that the fractured and faulted lithosphere is associated with grabens and rifts in which mantle material has risen to within 10 to 15 km from the surface. The grabens and rifts are marked by volcanism in which the dominant volcanic rocks are olivine--and tholeiitic--basalts, with a sprinkling of more acid volcanics ranging from dacite to andesite. Following A. Rittman the basalts are believed to have originated in the asthenosphere when the lithosphere was broken up under a tensional stress regime; the acid volcanics were formed by magmatic differentiation within the crust. it was argued that ideal geothermal reservoirs are capped with altered ash deposits or other nonpermeable volcanics. To feed such reservoirs conduits are required which are naturally located on fault or shear zones. The two areas selected as favorable for future geothermal power development are located between Talasea and Lolobau Is., say around Hoskins; and near Rabaul, between Matupi Harbor and Matupi. As a type area, the rift between the Gazelle Peninsula and New Ireland resembles the Afar triangle, at the northern end of the Great Valley Rift system of Africa
