174 GLACIAL ACTION IN AUSTRALASIA. 
stone. The travertine beds are often seen as cappings, 12 to 
20 ft. in thickness, on the sea cliffs, producing by their waste 
extensive talus slopes, covering from sight the underlying beds. 
This was the case in several instances when the presence of 
boulder clay was indicated by the existence of numerous large 
erractics on the adioining beach. The boulder clay becomes 
visible only where the lines of denudation have cut through 
the newer deposits, or the sea has exposed a section in the 
cliffs of the coast. 
The North Coast, as far as it was explored by the beach (from 
Point Marsden to Smith’s Bay) is more or less marked by the - 
presence of large erratics. As many as twenty could in places 
be counted within sight at one time. These measured up to 
12 ft. in length, and consisted chiefly of granites, quartzites, 
eneissic, and other metamorphic rocks. No similar rocks occur 
on the island within many miles of the localities over which they 
are now distributed. The greatest numerical groupings of these 
transported blocks, on the north coast, occurred about three- 
quarters of a mile west from Point Marsden, and at Smith’s 
Bay. . 
The best exposure of glacial till met with during the visit 
was at Smith’s Bay. A very characteristic till bed is seen in 
the cliffs on the east side of the Bay, and contains some very 
large stones highly glaciated. The cultivated ground in the 
neighbourhood is the product of this boulder clay, and, in 
places, is so thickly strewn with large erratics that the land 
has had to be cleared of these before it could be ploughed, and 
in some cases the ground is too stony to be worked atall. Many 
of the boulders give the clearest evidences of their glacial origin 
by their grooved and polished faces. An extensive exposure of 
these beds can be seen in a small creek and adjoining scrub 
land, on the east side of the main road to Queenscliffe, about 
half a mile from the Bay. A sketch section of the beds, as they 
occur ot Smith’s Bay, is given on Plate II. 
A reference to the map (Plate I.) will show the occurrence 
of the glacial deposits in their inland extensions. At Emu 
Bay, as well as at Smith’s Bay, the boulder clay follows the 
low ground. The Emu Bay branch runs almost due south, 
skirting the base of Retties Bluff, and continues in the same 
direction to Salt Lagoon, in sec. 63, Hundred of Menzies, a dis- 
tance of 7} miles. The Smith’s Bay branch passes through the 
gap, in the Gap Hills, to about the same southern limits. The 
glacial exposures are for the most part marked by the presence 
of erratics, which are often of large size. 
At Smith’s Bay the till rests uncomformably on reddish and 
dark-coloured sandstones and shales of doubtful age. They are 
probably of paleeozoic age, but newer than the Cambrian beds 
of the mainland. The formation just described exists as the 
