The Balmoral moraines near Lake Pukaki, Southern Alps: a new reference area for the early Otira Glaciation in New Zealand

Terminal moraines and outwash plains associated with Loopline Formation glaciogenic deposits near Kumara in the Taramakau River valley, north Westland, have long been regarded as key morphostratigraphic representations of the early phase of the Otira Glaciation, correlated with Marine Isotope Stage (MIS) 4. Recently published cosmogenic dates and soil stratigraphic studies indicate that moraines and outwash plains in the Loopline type area were formed during the later phase of the Otira Glaciation at c. 25 cal kyr BP, and therefore do not equate with the early Otira Glaciation. Beryllium‐10 dating of Balmoral Formation moraines at Lake Pukaki, on the eastern side of the Southern Alps, indicates an age of c. 65 kyr BP, confirming deposition during the early Otira Glaciation and correlation with MIS 4. The Balmoral moraines and proximal outwash plains at Lake Pukaki are therefore proposed as a new reference area for the early Otira Glaciation.