﻿254 



REV. W, HOWCHIN ON GLACIAL BEDS OP [May I908, 



o 



I 



c^ 



be 



p^ Lii 





L- /'^ '^ /^ "* r\ ^"^ 



On the upper slopes of the gorge 

 the till has been considerably- 

 weathered and eroded, and the 

 surface is covered with erratics. 

 Among these a dark porphyry is 

 a common form : one example of 

 this type, on the south side of the 

 stream, measures TJ feet in length. 

 On the north side of the river a 

 lenticular mass of brown grit 

 (measuring 10 feet in greatest 

 thickness) occurs in the lower till- 

 bed about halfway up the hill. 

 Several big granite-boulders of 

 various kinds also occur on that 

 side of the valley, near the junc- 

 tion with the underlying quart- 

 zites. In the course of three visits 

 to this outcrop several good gla- 

 ciated stones were obtained, and 

 others were seen that were too 

 large for removal. 



{d) Northern Areas : Sections. 

 (Figs. 2-6, 11, 12 & Pis. XIX, 

 XXIV, XXV.) 



Two geological sections are given 

 in figs. 11 & 12 (pp. 256 & 257), 

 which are typical of the northern 

 portions of the Mount - Lofty 

 Ranges and the southern and 

 eastern Flinders Eanges. 



Fig. 11 is a diagrammatic repre- 

 sentation of the main outcrops, as 

 they occur across the strike in a 

 west-and-east direction from Port 

 Germein, on Spencer's Gulf, to 

 Mount Grainger, which is situated 

 7 miles north of Oodla-Wirra 

 Eailway-station (on the Peters- 

 burg & New-South- Wales Border 

 Eailway), covering a distance of 

 60 miles. In this section the 

 glacial till makes eight distinct out- 

 crops, in anticlinal and synclinal 

 curves ; and in each case (in 

 association with the underlying 



