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EEV. W. HOWCHIl^ ON GLACIAL BEDS OF 



[May 1908, 





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and thence they are repeated in 

 successive folds, in an easterly 

 direction, to the Barrier Eanges 

 of New South Wales, in which last- 

 named locality Mr. D. Mawson, 

 B.Sc, has recently noted their 

 occurrence. This makes a width 

 across the main line of strike of 

 250 miles. 



III. Geological Age of the Beds. 



The discovery in 1879' of 

 Archceocyathince and other organ- 

 isms in the Palseozoic rocks of 

 Yorke Peninsula, and, at later 

 dates, of a similar fauna in the 

 Flinders Ranges, and also at 

 Sellick's Hill, in the southern por- 

 tion of the Mount-Lofty Ranges, 

 supplied important data for the 

 determination of the geological 

 age of a vast series of beds which 

 form the central highlands of 

 South Australia. While the occur- 

 rence of Cambrian fossils defined 

 the geological horizons locally, it 

 remained for many j'cars a doubt- 

 ful question as to how far the rocks 

 of the Mount-Lofty and associated 

 ranges, as a whole, could be re- 

 ferred to the same age. The pre- 

 vailing impression for some time 

 was that the Mount-Lofty E-anges, 

 with their highly-metamorphosed 

 rocks, were older than the Cam- 

 brian. 



Recent investigations have de- 

 monstrated that the highlands 

 extending from Cape Jervis in 

 the south, to Lake Eyre and Lake 

 Prome in the north, are included, 

 for the main part, in one great 

 geological series, the individual 

 members of which are conform- 

 able to each other. The beds 

 which carry characteristic Cam- 

 brian organic remains occur near 

 the upper limits of the series. 



^ Otto Tepper, Trans, & Proc. 

 Phil. Soc. Adelaide, 1878-79, p. 71 ; 

 E. Etheridge, Jun., Trans. Eoy. Soc. 

 S. Austral, vol. xiii (1889-90) p. 10; 

 E. Tate, ibid. vol. xv (1891-92) p. 183. 



