A STRATIGRAPHIC AGE OF ROTOEHU ASH AND LATE PLEISTOCENE CLIMATE INTERPRETATION BASED ON MARINE TERRACE CHRONOLOGY, MAHIA PENINSULA, NORTH ISLAND, NEW-ZEALAND

Rotoehu Ash, a widespread tephra marker in central and eastern North Island, occurs within terrestrial cover deposits overlying some shore platforms at Mahia Peninsula. Several loess units, tephra, and paleosols overlie shore platforms and provide age and paleoclimatic information for the period subsequent to shore platform formation. These data, along with faunal and floral samples, enable the terrace sequence to be correlated with the well-dated, late Quaternary coral reef sequence at Huon Peninsula, Papua New Guinea. The youngest shore platform at Mahia Peninsula on which the Rotoehu Ash occurs is correlated to the 59 ka B.P. reef crest; it does not occur on a shore platform correlated to the c. 40 ka B.P. reef crest at Huon Peninsula. Evaluation of the stratigraphic sequence on the 59 ka B.P. Auroa 2 shore platform results in an age estimate of the Rotoehu Ash of 52 +/- 7 ka B.P. Previous radiocarbon dates indicating an age of c. 42 ka B.P. are considered to be minimum values. Climato-stratigraphic sequences within southern and eastern North Island have been refined by using the chronology established at Mahia Peninsula.