Interglacial deposits in Joyces Stream (S74), Waimakariri Valley, Canterbury

The results from pollen analysis of Late Pleistocene peat and silts in Joyces Stream, considered with geological data, confirm that the interval between the successive Woodstock and Otarama ice advances in the Waimakariri Valley should have interglacial status. The palynological record at Joyces Stream commences at a stage when swamp vegetation had spread across a shallow lake occupying a depression eroded in Woodstock glacial outwash gravels. Nothofagus fusca ‐type forest flourished in the vicinity, but this was later replaced by grassland‐shrubland vegetation. The swamp became open water while the climate was changing from temperate to bleak near‐glacial conditions. Finally the lake was overwhelmed by outwash gravels as ice of the Otarama Advance reached almost to the site. The Joyces Stream interglacial event may be identified with either the Oturian or the Terangian Stage, according to which of two conflicting trans‐Alpine correlations is adopted. Apart from confirming the interglacial status of the Woodstock/Otarama interval, the palynological evidence has not contributed directly to a solution of the correlation problem.