240 



delta of the Murray. The river, through most of its course, 

 and especially in its passage through the hard Cambrian 

 slates, has the characteristics of an incised meander. Its pre- 

 sent channel must have been determined at a time when the 

 valley floor was at an even level with the upper limits of the 

 old rocks which now form the Mount Observation Range. 



Giles Creek takes its rise in the northern portions of the 

 present glacial basin, and follows the eastern limits of that 

 basin, just as the River Finniss, in the first half of its course, 

 follows the western limits of the same. The River Finniss 

 represents the western and southern, and Giles Creek the 

 northern and eastern, portions of the basin. In both 

 cases the respective tributaries of the streams are gathered 

 from the older rocks which form a rim of highland around 

 the glacial basins. 



The same strongly differentiated botanical features seen 

 in the Mount Compass district, between the Cambrian and 

 glacial areas, are equally marked in the district now under 

 consideration. The prominent ridges of old rocks carry big 

 timber or are cultivated, whilst the glacial areas, represented 

 by the River Finniss Valley, and more particularly by the' 

 sandy ridge between Mount Observation and Giles Creek, 

 are covered by a dense and dwarf scrub characteristic of the 

 glacial country. The latter improves greatly in quality 

 where, bordering on the outcrops of the older rocks, it receives 

 contributions of stronger soil washed down from the adjacent 

 hills. 



Glacial. — My attention was called by Mr. Jas. Stone, of 

 Bull's Creek (who had recognized the presence of granite 

 boulders in the clay), to a road-cutting in glacial till in the 

 northern parts of this basin. The cutting is situated on the 

 Strathalbyn and Bull's Creek Road, about four and a half 

 miles from Strathalbyn, a little west of Gemmell's Hill, and 

 within the valley of Giles Creek (Section 1823, Hundred Kon- 

 doparinga), (plate xxxix.). The section is about 80 yds. 

 long and 10 ft. in greatest height. Numerous erratics 

 occur in the clay, and others which were thrown out at the 

 time of making the cutting are lying on the top of the bank. 

 More than twenty erratics of granite, of various types, were 

 counted within the distance occupied by the cutting, several 

 having a diameter from 1 to 2 ft., and one that had been 

 removed to the side of the road measured 4 ft. in length, 

 2 ft. in width, and 1 ft. 9 in. in height. A goodly number 

 of schistose rocks ("bluestone") that are commonly met with 

 in the till at Hallett's Cove and the Inman Valley, and which 

 frequently show glacial marks, were noted among the erratics 



