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the basalt. The talus formed by this much-jointed igneous rock 
is very extensive, and for the most part has covered both the 
white sandstone outcrop and the adjacent boulder clay. The 
probabilities, however, seem to be that the boulder clay underlies 
the white sandstone, and consequently the basaltic cap also. 
The white sandstone, which is inferior to the basalt through- 
out the district, Mr. Brown considers the equivalent of the sand- 
stone of the Inman Valley, with which it has a close resemblance. 
As the sandstones of the Hindmarsh, Inman, and Yankalilla 
districts sometimes carries glaciated erratics, there can be no 
doubt that it belongs to the same series as the underlying boulder 
clay of the neighbourhood. I saw no erratics in the sandstone 
on Kangaroo Island, but the analogy in other respects seems to 
point to its being the upper member of the glacial beds on 
Kangaroo Jsland as it is on the mainlana.* 
In defining the contour of the boulder clay in its landward 
extension on the south side of the Gap Hills, I am much indebted 
to the extensive local knowledge of Mr. John Turner, who 
assisted me in marking off its limits on the map (Plate V.), but 
the lines of occurrence must be taken as approximate only. 
So far as I saw the country, I am led to think that it is the 
occurrence of the glacial clay at the surface which forms the very 
productive cultivable land met with on the Island, but which, it 
is to be regretted, forms but limited patches between extensive 
stretches of unproductive limestone and sandy country. 
Only in one instance did I observe the Glacial Till in direct 
contact with the bed rock, and then it was resting on soft shales 
that were unfavourable for the preservation of glacial features. 
The glacial remains described in this paper extend in a straight 
line 12 miles from east to west, and seven miles in a north and 
south direction, and greatly enlarges the area previously known 
to have been under glacial conditions in South Australia. The 
extinct ice field may now be described as extending over 70 miles 
from Smith’s Bay, Kangaroo Island, on the west, to Hindmarsh 
River on the east, and not less than 40 miles in a north and 
south direction from Kangaroo Island to Hallet’s Cove on the 
mainland. There is the highest probability that further research 
will show that the ice action has been much more extended than 
the area now described, although the general prevalence of sand 
and travertine over the lower portions of the Island greatly 
masks the underlying strata in positions where the glacial beds 
are most likely to occur. 
* A similar white sandstone is seen at Hallet’s Cove, where it overlies 
the boulder clay, and separates the latter (within the limits of the amphi- 
theatre) from the overlying fossiliferous Miocene limestone. The line of 
unction between the sandstone and Miocene beds exhibits numerous 
erratics. 
