This includes Tasmania but the rest of Australia misses out, despite the scabby little smears of ice which sat sadly and forlornly on the tops of the Snowy Mountains. Neither of these classes of theory account for periodicities of ice advance and retreat with in a glacial episode. Milankovitch theory of the ice ages is current best bet for patterns of ice advance detected for about the last 900,000 years. For detailed discussion of the theory refer to Williams et al 1997.
Exact mechanisms leading to ice sheet accumulation are still uncertain.
Ice core records of glaciation and atmospheric composition offer valuable insights into the dynamics of glacial age climates. Cycles are also recorded in the marine isotopic record. These patterns contrast very strongly with circumstances of the Holocene where relative stability is the order of the day. This is interpreted to be indicative of a threshold being crossed during the process of deglaciation which effectively suppressed to mechanisms inducing insatbility at earlier times. Astronomical calibration of loess - palaeosol deposits at Luochuan, central Chinese Loess Plateau.