The Southern Hemisphere glacial record - Antarctica and New Zealand

Abstract

The New Zealand terrestrial glacial record and that of the Dry Valleys area, McMurdo Sound, Antarctica are compared in a chronological table of events. The Antarctic chronology given is that of a stable East Antarctic Ice Sheet hypothesis, while an alternative postulates a Pliocene collapse of the ice sheet. Whereas the New Zealand record commences at about 2.5 Ma, the Antarctic record commences in detail at 15 Ma. Following the New Zealand late Pliocene glacial events, a hiatus of over one million years occurs where the combined effects of uplift and erosion have almost entirely removed the terrestrial record. The ages of the Antarctic sequence have been determined by Art Ar dates of volcanic ash associated with the deposits, while the older New Zealand events have been dated by association with fluctuating sea levels and sequence counts. Younger New Zealand events are relatively well constrained by radiometric dates. The New Zealand Pleistocene concludes with a rapid warming at c. 14 ka which heralded the demise of the huge Pleistocene glaciers, while in Antarctica the end of the Pleistocene is marked by the disappearance of marine Ross Sea ice.