THE PROBLEM OF ANTIQUITY OF MAN IN AUSTRALIA 17 
Pleistocene history; Hills (1939 b), however, holds that tectonic 
movements caused the coast to retreat to its present position. 
In many parts of Australia are remains of a raised beach at about 
15-20 ft. above sea level containing mollusea and foraminifera 
which suggest a climate somewhat warmer than that of the present 
day (Howchin, 1923, Tindale, 1933). This beach does not appear 
to correspond with Wright’s pre-glacial 15-foot beach of Western 
Europe, but was probably formed during the slight general post- 
glacial refrigeration already mentioned; Daly (1934) estimated 
that the change happened about 4,000 and Cotton (1926) 3,000 
to 5,000 years ago, but Milankovitch’s curve indicates 10,000 years. 
River terraces exist at various heights up to 100 ft. above present 
stream level. Extensive dunes fringe the coast in many places; 
the older consolidated dunes contain remains of extinct marsupials 
and in places are covered with volcanic ash, and the youngest 
dunes are still accumulating. Hills (1939 a) considers that the 
consolidated dunes were formed during the low-water glacial 
phases, and that the comparatively minor dunes of loose sand are 
post-glacial. 
Some Australian raised beaches and submerged shore-lines may 
be due principally or entirely to eustatic changes in sea level; but 
tectonic movements in certain localities are indicated by such 
features as the anticline across the lower course of the Murray 
River (Howchin, 1929), and in north-western Victoria and adjoin- 
ing areas by elevation during Pleistocene and Holocene times 
accompanied by faulting and warping (Hills, 1939 b). If we accept 
as approximately correct Daly’s estimate that the melting of all 
ice-caps and glaciers would raise average sea level about 130 ft., 
the Ooldea raised beach at 380 ft. above present sea level and about 
80 miles from the coast must have been elevated, at least in part, 
by tectonic movement. The fact that voleanoes were active in 
south-eastern Australia during Pleistocene and post-Pleistocene 
times suggests that earth movements were in progress. 
The problem of correlating Pleistocene glacial deposits, river 
terraces, raised beaches, submerged strandlines, sand dunes and 
alluvial deposits in Australia has not yet been solved. We have 
no knowledge of the order in which extinct marsupials died out, 
and consequently their fossil remains do not date the deposits in 
which they are found; some species and genera possibly did not 
survive the early Pleistocene stages, but others such as Diprotodon 
appear to have lived until recent times; Thylacinus and Sarco- 
philus are extinct on the mainland but survive in 'Tasmania. 
Lewis in 1923 demonstrated three Pleistocene glacial phases in 
Tasmania and in 1933 he gave a more detailed account of them. 
