GLACIAL ACTION IN AUSTRALASIA. 175 
bed-rock along the northern coast from Point Marsden to some 
distance west of Smith’s Bay. The glacial clay is not only un- 
conformable to this series, but its lithological features suggest 
a much more recent formation. 
The glacial till is overlain by two beds of very diverse 
character. The first, in ascending order, is a white, friable, 
quartzose sandstone, false-bedded in places, and is easily re- 
duced under atmospheric influences to a loose sand. The dis- 
integration and distribution of this bed may be the source of 
much of the sandy country which forms the bane of the agri- 
culturists on the island. I saw no erratics in this sandstone, 
which has evidently been formed under diiferent conditions from 
the underlying till, and yet may be in some way connécted with 
it. A coarse gritty sandstone, sometimes highly indurated, 
occurs in association with the glacial drift at Hallet’s Cove, 
Yankalilla and Inman Valley, and in these localities it not 
unfrequently carries erratics, but not always. At Queenscliffe 
(K. Is.) the sandstone rests on an indurated clay at sea level, 
but the latter is not sufficiently exposed to determine clearly 
whether it be the till or not. 
The white sandstone, just described, is overlain by an interest- 
ing sheet of basalt, forming flat-topped eminences at Kingscote 
and along the Gap Hills range, over a lineal distance of 12 miles. 
The basalt reaches a maximum thickness of about 200 ft., and 
is intimately jointed, vertically and horizontally, which leads to 
its breaking up readily into small prismatic fragments from 
2 to 4 in. in length. Im consequence of this physical feature 
of the basait, the sides of the hills are thickly strewn with 
screes and talus belts at a much lower level than the parent 
rock. The geological age of this igneous overflow has not been 
determined, but it is probably Tertiary, or even later. 
Up to the present the stratigraphical relationship which the 
glacial beds may bear to the lower tertiaries has not been made 
clear. Although Eocene limestones occur at Queenscliffe, and 
also at a locality inland from Smith’s Bay, they are not seen 
in close proximity to the glacial beds. At Queenscliffe, be- 
tween tides, a stiff clay is seen to underlie the Eocene limestones, 
and apparently the same clay underlies the white sandstone and 
basalt at Kingscote, a mile further to the north, but from its 
low position and imperfect exposure it is a little doubtful 
whether it be the boulder clay or not. Its stratigraphical posi- 
tion is, however, analogous to that of the boulder clay on the 
north coast, and if it be the same bed which is seen under 
the Eocene cliffs of Queenscliffe there is a strong probability 
that the glacial features date from pre-eocene times. This 
point, however, awaits confirmation (a), as also the main centre of 
(a) Since this paper was written evidences have been obtained which leave little doubt 
that the clay referred to is of glacial origin. 
