Palaeomagnetism of New Zealand glacigenic deposits

Abstract

The late Cenozoic record of glaciation of the Southern Alps is one of the most detailed in the Southern Hemisphere. Despite attempts to improve the resolution of the terrestrial record, recent research has confirmed the presence of a gap in the terrestrial record of glaciation between 2.1 Ma and 0.35 Ma which has been attributed to the combined effects of rapid uplift and erosion (Suggate 1991). In contrast, evidence from South America and Tasmania suggest that glaciers were most extensive in the Southern Hemisphere middle latitudes at about 1 Ma (Clapperton, 1991; Fitzsimons and Colhoun, 1991; Fitzsimons et al., 1993). In these two locations palaeomagnetic studies have proven to be a useful means of identifying Early Pleistocene deposits on the basis of polarity of glaciolacu-strine sediments. Research on similar problems in Tasmania (Pollington et al., 1993) stimulated a pilot project that was designed to test the existing New Zealand stratigraphic model by examining the polarity of glaciolacustrine sediments.