32 AUSTRALIAN QUATERNARY CLIMATES AND MIGRATION 



mania there were at least three glaciations, in local terminology, 

 the Margaret, Yolandean, and Malannan stages, most fully 

 described by Lewis (1945). These are respectively probably the 

 equivalents of the Wurm, Riss, and Mindel glacial stages of the 

 Northern Hemisphere. The Margaret glaciation occurred after 

 the formation of Bass Strait, the Yolandean and Malannan 

 before. Two glaciations have occurred at Mt. Kosciusko (7328 

 ft.) on the Kosciusko plateau, the newer of which David (1923) 

 has correlated with the Wurm (Margaret), and the older with the 

 Mindel (Malannan). In regard to the more recent changes in 

 climate, we are concerned with those after the Margaret glacia- 

 tion ; this David divided into the Post- Wurm Mountain Glaciation 

 and the Wurm Glaciation, but seemingly, these may be regarded 

 as phases of the Margaret. In respect to the summit of Mt. 

 Kosciusko, lie states that the Mountain Glaciation extended down 

 to 6,400 feet and the Wurm down to 6,150 feet, 928 and 1,178 feet 

 respectively below the summit. 



The paths of the lows have changed with the passing north and 

 south of the glacial, Postglacial, and interglacial periods: the 

 eastern and western littorals have been most affected by the con- 

 temporaneous passing backwards and forwards of the rain-belt. 

 Information concerning the present paths of the depressions is 

 far from complete and any deductions from it must necessarily 

 be tentative. 



The general direction of the high pressure belt with its comple- 

 mentary lows is, in the Australian region, a little south of east. Due 

 to the existence of a greater land-surface in the Northern Hemis- 

 phere, their direction is there less defined. Brooks (1926) states: 



Although the paths of the individual depressions in temperate regions often 

 appear to be erratic, it has been found possible to classify them into a number 

 of tracks, which are more usually followed than the intervening regions. These 

 tracks have a preference for moist, areas, especially such inland seas as the 

 English Channel, the Baltic, and the Mediterranean, or for well watered plains 

 such as Hungary and Poland . . . The question of the tracks of depressions is 

 important for palaeometeorology, for a considerable degree of permanence has 

 been attributed to them. 



As most of the reliable rainfall along the south coast of Aus- 

 tralia is associated with the winter Antarctic low, the average 

 position of its axis is important from the standpoint of this 

 discussion. Taylor (1920) shows that it trends E.S.E. by a 

 straight line from a point about 250 miles south of Cape Leeuwin 

 and that it enters Bass Strait between King Island and Tasmania. 

 This is the path at present, 4,000 years after the Postglacial 

 Optimum ; it was also the path 4,000 years before the Postglacial 



