Reconstructing temperature during the Last Glacial Maximum from Lyndon Stream, South Island, New Zealand using beetle fossils and maximum likelihood envelopes

Abstract

This paper presents fossil beetle data from a Last Glacial Maximum site at the Lyndon Stream, in the Canterbury foothills, South Island, New Zealand. Paleotemperatures are derived using the maximum likelihood envelope (MLE) model developed for regions where modern distribution data are incomplete [Marra et al., 2004. Late quaternary climate change in the Awatere Valley, South Island, New Zealand using a sine model with a maximum likelihood envelope on fossil beetle data. Quaternary Science Reviews 23, 1637–1650]. The MLE model results indicate that summer temperatures in the Canterbury foothills, in close proximity to the major Rakaia glacier, at ca 22,000 14C yr BP were between 0.5 °C warmer and 1.9 °C cooler than present day in February (summer). Mean minimum winter temperatures ranged between 1 °C warmer and 2.2 °C cooler than the present day. These apparently surprising results confirm and quantify existing climate reconstructions from plant macrofossils from this site [Soons, J.M., Burrows, C.J., 1978. Dates for Otiran deposits, including plant microfossils and macrofossils, from Rakaia Valley. New Zealand Journal of Geology and Geophysics 21, 607–615]. They are consistent with new evidence of relatively mild conditions at least during some periods within the Last Glacial Maximum chron in New Zealand.