THE PROBLEM OF ANTIQUITY OF MAN IN AUSTRALIA 19 
Tasmanian National Park near the 4,000 ft. contour and also gave 
rise to high-level tarns at Kosciusko and moraines near ‘Towns- 
hend’s Pass in the same district at 6,400-6,700 ft. This was followed 
by deglaciation, rising sea level, voleanic eruptions at Mount 
Gambier, South Australia, and Tower Hill, Victoria, and then by 
a negative eustatic movement in sea level of about 10-15 ft. 
In Tasmania Lewis recognized raised beaches and river terraces 
at 50-100 ft., 40-50 ft. and 5-15 ft. above sea level, and drowned 
valleys at 150 ft., 30-60 ft. and 20 ft. below sea level. He tentatively 
correlates these and other features with the three glaciations. 
Conglomerates of quartzite pebbles at 50-100 ft. above sea level 
in southern Tasmania, claypan deposits underlying Mowbray 
Swamp,’ and the Helicidae sandstone (consolidated dunes) at 
100 ft. on the islands of Bass Strait he regards as pre-Malannan. 
The channel of the Derwent River is eroded to 150 ft. below sea 
level and the strandline must have dropped by this amount; he 
correlated this with eustatic lowering of sea level during Malanna 
glaciation, when Tasmania and Australia were united by a land- 
bridge. River terraces and raised beaches at 40-50 ft. he assigns 
to the Malanna-Yolande interglacial phase; the conglomerates of 
these terraces in southern Tasmania consist almost entirely of 
pebbles of dolerite and Permo-Carboniferous mudstone. Vast 
changes in physiography took place during the Malanna-Yolande 
interglacial phase. There is some evidence of river erosion 30-60 ft. 
below sea level which he considers to correspond with the Yolande 
phase. The formation of the 5-15 ft. raised beaches and the lowest 
river terraces he correlates with the Yolande-Margaret interglacial 
phase. The development of existing river courses and a channel 
20 ft. below the floor of the Derwent estuary he attributes to the 
Margaret glacial phase. Since the latest glaciation he considers 
that there has been a progressive rise in sea level and that the 
valley of the Derwent has been drowned as far upstream as New 
Norfolk. 
Edwards observed in north-west Tasmania at least two raised 
shorelines, one at 5-15 ft. and the other at 40-50 ft., with river 
terraces at corresponding heights and, in the Mersey and Forth 
valleys, suggestions of a third strandline at about 100 ft. above 
sea level in the form of doubtful remnants of river terraces; 
Johnston (1888) had noted a raised beach at this level on Chappell 
Island. The valley of the Tamar can be clearly followed on the 
Admiralty Chart to 15 fathoms and less clearly to 20 fathoms, and 
contours of submarine valleys in the neighbourhood of Hunter 
Island and Three Hummocks Island can be traced to 25 fathoms, 
6. For notes on Mowbray Swamp see Noetling (1911). 
