Evidence of Holocene uplift in east New Britain, Papua New Guinea

Abstract

We present the first published evidence of uplift along the eastern coast of New Britain, Papua New Guinea based upon 230Th dating of uplifted Holocene coral reefs. Although uplift rates of the nearby Huon Peninsula are well constrained (∼2–3 m/ka), little is known about vertical motion along the eastern margin of New Britain. Based upon relative sea-level curves for Papua New Guinea, present sample elevations, and estimates of paleowater depth of four in-situ Holocene corals we calculate an average uplift rate of 1.6 ± 0.4 m/ka for the southeast coast of New Britain. We suggest underplating of subducted sediment as a possible mechanism for uplift of the reefs.