DUNE PHASES AS TIME-TRANSGRESSIVE PHENOMENA, MANAWATU, NEW-ZEALAND

New Zealand's most extensive Holocene dunefield is situated in the Manawatu and adjoining regions. Evidence collected from the area, including 25 radiocarbon dates, suggests that the dunefield developed in phases, with the first probably initiated at the coast earlier than 6000 years ago. The first phase may have ceased near the coastline around 4500 years ago, bur dunes continued to migrate until they reached 16 km inland ca. 1600 years ago. About 3500 years ago, dunes again began migrating inland from the coast with some still active 400 years ago. The time-transgressive nature of transgressive dune deposits and the possible causes of the dune phases are discussed.