J. LeConte—Ancient Glaciers of the Sierras. 335 
glaciated rock. In fact, we have here admirable examples of 
the two kinds of glacial lakes ; those of one kind are accumu- 
lated in rock basins scooped out by glacial erosion ; those of the 
other kind are accumulated behind terminal moraines; the for- 
mer are found only in the higher slopes, the latter are usually 
found lower down. These latter graduate insensibly into marshes 
and meadows. Standing on the top o . Dana on my pre- 
vious trip, I am sure more than 50 of these lakes and marshes 
could be counted. 
hike cliffs and circular amphitheaters still filled with snow, 
clearly showed that these were the deserted homes of many 
ormer glaciers. 
ITV. Carson CaNon Guacier. 
Hope valley and Lake valley (Lake Tahoe valley) le coun- 
tersunk upon the very top of the Sierras and in the direction 
of the chain. ‘This chain, therefore, is divided at this point 
into two crests, east and west of these valleys. From the plains 
of Carson, on the east side of the Sierras, our party passed west- 
ward through Carson Cafion, a magnificent gorge which cuts 
through the eastern crest into Hope valley. Throughout this 
cation I observed the clearest evidences of glacial action, in the 
form o scored, polished and moutonnée surfaces. In 
the south down Hope valley, and turned at right angles and 
” 
South of Hope valley is Faith valley, and to the south of this 
Charity valley These three are separated from each other 
moutonnéed in the most perfect manner; they are, in fact, 
€ lips of consecutive lake basins scooped out by a glacier. 
