Abstract Two radiocarbon ages are reported: 4610 ± 60 yr BP (Wk-5874) for wood in lake sediments which were later buried by till during a glacier advance; and 1800 ± 50 yr BP (Wk-5875) for wood in glacio-fluvial outwash. Each of these ages is assumed to record events which had already been dated, although in both cases the new samples come from different locations. The stratigraphic and geomorphic evidence from the dated sedimentary strata provides new perspectives on events in the lower Waiho River valley associated with glacial advance and recession, and fluvial deposition and erosion, during the mid- and late-Aranui Interglacial. These include the presence of a lake at least 300 m long c. 4600 yr BP; a clear indication that an extensive glacial advance occurred soon after that time; and the occurrence of a substantial glacial event associated with the deposition of a thick sheet of outwash which filled the width of the valley, c. 1800 yr BP.
Keywords radiocarbon ages; lake sediments; till; glacio-fluvial outwash; glacial advance; recession; fluvial deposition; erosion; Aranui Interglacial
R01008 Received 27 June 2001; accepted 22 January 2002; published 27 September
2002
©Journal of The Royal Society of New Zealand, Volume 32, Number
3, September 2002, pp 415-425
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