88 I. C. RUSSELL — HANGING VALLEYS 



to 50 or more miles long and their tributary hanging valleys from 1,000 to 

 2,000 feet above their bottoms. If glaciers excavated even the portion 

 of these valleys which are situated at a lower level than the floors of their 

 tributary hanging valleys, not taking into account the portions of the 

 valleys above such horizons, it is legitimate and logical to demand that 

 evidence be produced as to the disposition the glaciers made of this 

 material. 



In traversing such canyons as those occupied by Methow and Wenache 

 river3 and the valley of lake Chelan, in Washington, or the Tuolumne 

 and other similar canyons in California, one can not fail to be impressed 

 with the fact that the amount of morainal material associated with them 

 is insignificant in reference to the size of the excavations from which it 

 was derived. In several typical instances the morainal material in sight 

 or which may reasonably be assumed to be present, if spread over the 

 glaciated surfaces of the canyons from which it was obtained, would, it 

 is safe to say, form a layer only a few feet, and in most instances only a 

 few inches, thick. 



It can, perhaps, be claimed that the glaciers ground their grists so fine 

 that the streams supplied by their melting carried it away and distrib- 

 uted it so widely that it is no longer recognizable ; but glaciers carry 

 fine and coarse material alike, and the coarse material should, in the 

 instances under consideration, still remain where the glaciers left it. 

 While there is no known ratio between the coarse and fine debris of 

 glaciers, we know that in many instances conspicuous deposits of till, 

 boulders, etcetera, are laid down by them. For example, in the case of 

 the continental glaciers that formerly occupied the northern half of 

 North America the moraine and till sheets are far more conspicuous 

 than the records of abrasion left by the same ice sheets. So, too, in the 

 case of many alpine glaciers conspicuous lateral and terminal moraines 

 remain as evidence of the work done. Such general considerations, as 

 most students of glaciers will admit, no doubt are sufficient in them- 

 selves to sustain the demand for ocular evidence as to what has become 

 of the rock removed in case hanging valleys are due to differential ice 

 erosion ; but, as I think, a more specific argument in this connection 

 can be presented. 



EVIDENCE DERIVED FROM STUDY OF BLOODY AND LUNDY CANYONS 



On the southwest border of the basin of Mono lake * there are several 

 deep glaciated canyons, some of which have typical hanging valleys 

 on their side3. Two of these canyons, namely, Bloody canyon and 



* Israel C. Russell: [" Quaternary history of Mono valley, California." Eighth Annual Report 

 U. S. Geol. Survey, part i, 1889, pp. 331-333, 337-340. 



