Glacial Beds of Cambrian Age in South Australia

I ntroduction . In April 1901, the present writer read a ‘Preliminary Note on the Existence of Glacial Beds of Cambrian Age in South Australia,’ before the Royal Society of South Australia. Subsequent investigations have demonstrated the great extent of these beds, both in thickness and in geographical prevalence, and have materially strengthened the evidences of their glacial origin. Publication of these results was delayed until the stratigraphical relationships of the beds in question had become better known. Researches into the geology of the Mount-Lofty and the Flinders Ranges were undertaken for this purpose, with the result that the subject can now be discussed upon definite data. The beds under review have their southernmost outcrop on the Onkaparinga River, 20 miles south of Adelaide. South of this position they become obscured by the Tertiary sandstones of McLaren Vale, and by a fault of some magnitude in which the higher beds of the Cambrian series are brought into juxtaposition with the lower beds at a divergent strike. North of the Onkaparinga, the glacial beds are occasionally seen as inliers of the Tertiary sandstones and clays, until the River Sturt is reached, 7 miles south of Adelaide. Here the beds cross the stream obliquely, about 1 mile from the main South Road, and occupy both sides of the valley for a distance of nearly 2 miles up stream. The glacial beds in this locality are determined on their northern side by a dip-fault, which cuts them off. From this point, northwards, the deep