296 TJie American Geologist. May, 1899 
from being like that of an ordinary ground moraine, and it is 
scarcely surprising that Russell pointed out the possibility of 
its having been formed in some other way. Its geographical 
extent, however, proves that it was formed in the vicinity of 
the edge of the tongue of the glacier. 
5. The Northern Unglaciered Regio7i. 
I did not visit the districts north and west of the Klondike 
river and cannot, therefore, pronounce as to whether still furth- 
er division into zones can be made. Compared w'ith what is 
seen to the south however in the above described district the 
region acquires a very pronounced character after one leaves 
the Pelly river behind. It may be studied most conveniently 
in the gold district lying between the Klondike and Indian 
rivers. All the hills are rounded and have no trace of sharp 
outlines either on a large or a small scale ; they are divided ofif 
from one another by valleys with rounded sides varying in 
depth according to the size of the watercourses flowing 
through them. Solid rock is only occasionally met with on 
the loftiest water divides and in the frequently steep slopes 
down to the larger rivers. In other places the rock foundation 
is everywhere covered with vegetation beneath which there is 
a thick saprolite of rock decayed in situ. This is so soft that it 
may be cut by a knife and the marked transition from one to 
another of the different coloured layers of graphite, chlorite, 
and biotite schist, as well as the undecayed quartz veins, can 
still be discerned. 
That this decayed crust cannot have arisen ex- 
clusively since the glacial period may undoubtedly be con- 
sidered a certainty and hence we have a direct and decisive 
proof that this part cannot have been covered with glaciers or 
land-ice. It occurs, however, also in the deepest parts of the 
valleys, which for reasons we shall presently give are not very 
old ; and if we are not willing to assume that the later portion 
of the Tertiary period or some part of the Quaternary had a 
nuich warmer climate than the present we have here a proof 
that a pronounced rock decay can take place amid climatic con- 
ditions not very dissimilar from those now prevailing immedi- 
ately south of the polar circle in Yukon. The heads of the 
valleys are often of a regular amphitheatrical shape and there 
