CORRASION BY GRAVITY STREAMS 60 



canons, and a more rounded appearance to the broader 

 valleys. Thus half dome presents a vertical face to the 

 profound canon of the Teuaya, and shows a more gentle 

 slope to the moraines of the Merced. Similarly for the 

 domes of the Little Yosemite. Watkin's Dome has a steep 

 face in the Tenaya ; El Oapitan Dome gives place a little 

 below its summit to a vertical face in the Yosemite. The 

 domes of Yosemite, as they stand, appear to be products 

 of exfoliation, but from a general study of the valleys 

 leading from Mount Dana to Yosemite, they appear to 

 have stood in causal relation to the action of earlier and 

 larger ice floods before exfoliation repeated their older 

 outlines. Thus the great domes appear to be roche 

 moutonnees, which during a later stage of valley glaciation 

 have been sapped on their canon aspects and have given 

 rise to the steep faces of which Half Dome is an example. 



2. Milford Sound (South-western New Zealand.)— The 



fiord is some twelve miles in length and originates in the 

 confluence of two profound canons, the Arthur and Oleddau 

 Valleys. The walls rise about 5,000 feet out of the fiord 

 and are composed of strong crystalline schists and granitic 

 rock types. A large tributary enters five miles below the 

 head of the fiord. The narrowest portion of the main 

 valley is situated near the entrance and is confined between 

 two walls, almost vertical, the southern one being 5,600 

 feet, and the northern one about 5,000 feet high. Thence 

 they rise in places less steeply to the 9,000 feet level. The 

 width of the canon "narrow" between these two walls is 

 a mile and a quarter. 



On the northern wall occurs a splendid example of a 

 hanging valley, while about fifty yards from its point of 

 discharge into the Sound the salt water is 1,500 feet deep. 

 The northern wall is steeper than the southern, and 

 possesses some remarkable examples of Hanging Valleys 



