198 PROCEEDINGS OF SECTION C. 
The thickness which the glacial beds may attain in 
southern Yorke Peninsula is an interesting point, but has ~ 
not been definitely settled. At Tocchi Lagoon, situated one 
mile east of Yorketown, the Government put down a bore, 
which went threugh clay and sandstone to a thickness of 
305 feet. The last eleven inches was recorded as in “ very 
hard blue rock,” which was assumed to be bedrock, and the 
bore was stopped. It may easily be that this hard rock 
was an included boulder of quartzite in the clay, and did not 
prove that the glacial beds had been actually penetrated to 
their full depth. 
Work still remains to be done in this district in tracmg 
the limits of the glacial beds in their northward extension 
in the Peninsula, and also in determining whether the 
glacial clay, which passes under the sea at Point Turton, on 
the eastern shores of Gulf Spencer, outcrops on the western 
shores of that gulf. ; 
(c.) Glacial Beds of Assumed Cambrian Age.* 
An entirely new feature in Australian Geology has been 
supplied by the discovery of an undoubted glacial Till in 
rocks of a very remote age. The beds in question consist 
of unstratified clays and sands, carrying grit, rounded and 
angular stones, and large blocks up to nine feet in length— 
all irregularly distributed through the *unstratified matrix. 
The formation, when exposed to atmospheric conditions, 
splits into rough slabs along incipient or imperfect cleavage 
planes. The dip is uncertain, except when laminated 
shales or impure limestones are interbedded in the Till, which 
occasionally occurs. The included stones are, in many 
cases, foreign to the district, and frequently carry on their 
surfaces the evidences of ice-action in polished facets and 
strie. 
The Till was observed, in the first instance, m the valley 
of the Sturt River, about seven miles south of Adelaide, 
where the nearly vertical cleavage has led to the formation 
by river erosion of mural cliffs of great size. The beds, 
after passing out of sight under newer deposits towards the 
south, reappear in the valley of the Onkaparinga, about 
seven miles up from the mouth. At a distance of about 160 
miles north of Adelaide, the Till beds outcrop in several 
parallel belts, running in a north and south direction. Five 
of such parallel outcrops are known to occur in an east and 
west direction, extending over 100 miles of country at night 
*Ref. Trans. Royal Society, S.A., 1901, Vol. xxv., p. 10. 
