﻿234 REV. w. HowcHrN- ON^ GLACIAL BEDS OF [May 1908, 



11. Glacial Eeds of Cambeiai?^ Age in South Australia. By 

 the Eev. "Walter Howchin, F.G.S., Lecturer in Geology 

 and Palaeontology in the University of Adelaide. (Eead 

 November 20th, 1907.) 



[Plates XIX-XXVI.] 



Contexts. 



Page 



I. Introduction , 234 



II. Geographical Extent 234 



III. Geological Age of the Beds 236 



IV. Description of the Beds 239 



{a) General Features. 



{b) The Erratics. 



(c) Glaciation. 



{d) Effects of Mechanical Straiu. 



V. Illustrative Sections 248 



{a) Onkaparinga-River Section. 

 \h) The Sturt- Valley Section. 

 (c) Appi la-Gorge Section. 

 {d) Northern Areas : Sections. 



VI. General Considerations 255 



{a) The Ice- Agent. 



{b) ? Interglacial Periods. 



I. IXTRODUCTIOX. 



In April 1901, the present writer read a ' Preliminary Xote on the 

 Existence of Glacial Beds of Cambrian Age in South Australia,' 

 * before the Royal Society of South Australia.^ Subsequent in- 

 vestigations 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. Eesearches into 

 the geology of the Mount-Lofty and the Plinders Ranges were 

 undertaken for this purpose, with the result that the subject can 

 now be discussed upon definite data.^ 



II. Geographical Extent. 



The beds under review have their southernmost outcrop on 

 the Onkaparinga River, 20 miles south of Adelaide. South of this 



^ Trans. Roy. See. S. Austral, vol. xxv, p. 10. 



- Bibliographical references and other matters cognate to the subject will be 

 found in the following papers: — 'The Geology of the Mount-Lofty Ranges, 

 Part I ' Trans. Roy. Soc. S. Austral, vol. xxviii (1904) p. 253 ; and ibid.. 

 Part II, vol. XXX (1906) p. 227. 



