718 ALLEN DAVID HOLE 
Below 10,400 feet occasional accumulations of gravel and bowlders 
in variety occur as far as the limit as mapped for ice of the more 
recent epoch. Much of this débris below 10,400 feet cannot be 
distinguished from valley train deposits, and is therefore not 
included in the area of older glaciation. 
So far as composition and position are concerned, the deposits 
in these two areas west of Sheep Mountain might be referred to 
glaciation of the more recent epoch. They are classed as older drift 
because the valleys on the western side of Sheep Mountain from 
which it seems they must have been derived do not present the 
evidences of glaciation such as are found in the other high valleys 
which are known to have been occupied by glacial ice in the more 
recent epoch. It is possible that, with the fuller examination of 
this area which could be made if the forests were removed, relations 
of the drift of these areas may be established which will result in its 
reference to the more recent glacial epoch. 
OTHER AREAS 
At numerous other points, especially on the mesas between 
Remine Creek and Deep Creek, and again on points and ridges 
north of the East Dolores River, patches of bowlders occur which 
closely resemble glacial drift. But-either because of poor exposure 
of the deposit, or because no striated bowlders could be found, these 
areas have not been mapped. Although not recorded because the 
evidence is considered insufficient to warrant their classification 
with undoubted glacial deposits, it is nevertheless believed that in 
many cases they represent remnants of former moraines, or possibly 
in some cases outwash plains from glacial sheets of an earlier epoch. 
LANDSLIDES 
Although not to be classed as glacial phenomena, a brief dis- 
cussion of landslides and the topography resulting from them in the 
quadrangle is necessary because areas occur which present at the 
same time some of the characteristics of areas in which the materials 
have come to their present position by sliding or slumping, and 
some of the characteristics of typical morainal deposits. In most 
of the works previously cited reference is made to the frequent 
occurrence of landslides in the San Juan region, and in one, Pro- 
