Evidence for changes in Holocene vegetation and lake sedimentation in the Markham Valley, Papua New Guinea

Abstract

The past stability of vegetation patterns in the Markham Valley (6°30’S, 146°30’E), a lowland grassland area of Papua New Guinea, is investigated by pollen analysis of lake deposits and related palaeoecological techniques.¶ The predominantly organic sediments of Lake Wanum (alt. 35 m) span the last 9600 years. A 14C chronology supports the calculation of annual pollen deposition, sediment accumulation, and carbonised particle influx rates. At Yanamugi lake (alt. 170 m), 14C assays of the calcareous muds are influenced by variable ‘hard- water error’. A tentative chronology is based on palaeomagnetic and tephra correlations.¶ ...