LATE QUATERNARY COSEISMIC UPLIFT HISTORY OF HUON PENINSULA, PAPUA-NEW-GUINEA

Repeated episodic uplift at Huon Peninsula is represented by regressiv e terraces cut into raised late Quaternary reef tracts. Up to six regr essive terraces occur on the Holocene reef tract and up to 15 occur on reef tracts II and III, which span the interval from 33 ka to 52 ka. The uplift events are believed to be coseismic. The uplift behaviour a long 40 km of coast is now defined by surveys and radiocarbon dates fr om 15 new Holocene sites that add to previous results from 13 other si tes (Ota el., 1993), plus detailed surveys of three late Pleistocene s equences. The mean recurrence interval of uplift events was 1000 to 13 00 years in both the Holocene and late Pleistocene. The amplitude of u plift events averages about 3 m and generally increases from northwest to southeast in keeping with the regional late Quaternary trend, but for some events the uplift is approximately horizontal over 20 km or s o. Two tectonic subregions are recognised, which were uplifted togethe r by some Holocene events but not by others. There is no surface trace of Holocene faulting between the subregions and a buried fault probab ly separates them. (C) 1996 Elsevier Science Ltd