Physiography of the Glenelg River. 



115 



route, Ave may be sure so keen an observer would not pass it with- 

 out remark. He records that the native name of the hill now 

 known as the " Hummocks," was Kinganyu, and adds : " Proceed- 

 ing along the valley, the stream on our left (the Wando) vanished 

 at an isolated rocky hill; but, on cldser examination, I found the 



SECTION ON A-B-C 



Fig. 5. — Plan and section of " Tlie Hummocks." The contours are from 

 data collected by Mr. P. B. Nye. The jjlan shows clearly the wide 

 valleys carved ovit by the two streams in the softer rocks both above 

 and below the " gorges." 



apparent barrier cleft in two, and tliat the water passed through, 

 roaring over rocks. This was rather a singular feature in an open 

 valley, where the ground on each side was almost as low as the 

 rocky bed of the stream itself. The liill was composed of granular 

 felspar, in a state of decomposition .^ It is not so easy to suppose 

 that the river could ever have watered the valley in its present 

 state, and forced its way since through that isolated hill of hard 

 rock, as to suppose that the rock now isolated originally contained 



1 It is largely serpentine, with talc schists, quartz schists, phyllites, etc. 



