JjiirliK/ tJie Glacial Pei'iod. — Chainherlin. 273 
<j:lacial streams must have been very greatl}' <n'erloacled with 
detritus to have V)eeu depositing streams, to the extent I 
have indicated, if their slopes were notably greater than the pres- 
ent, especially in view of the greater volume of water whicU the 
streams then undoubtedl}' ])ore. 
Y. PJienomtna of th<- Latest Mo i-ainca. Within the outer mo- 
raine which bears this overwash apron of gravel are (jther and later 
moraines which present like phenomena, V)ut in no case are they 
more striking, except locally and narrowly, and in most cases the 
overwash and drainage phenomena are more feeble. The moraine 
next succeeding is almost equally coarse and rugged in its develop- 
ment and is accompanied l)y almost equalh' coarse and abundant 
drainage drift, indicating the existence of al)Out the same topo- 
graphic conditions: l)nt the later moraines generally display 
feebler drainage phenomena indicating a return t(j the Hatter con- 
dition of the earlier glacial epoch. 
YI. Ldcnstrinc ond ^fnn'))t■ PlwnouKiKi. Coutemporaneous 
with some of these later moraines and extending thence d<nvn to 
the close of the glacial i)eriod there was a succession of glacial 
lakes occupying the north-sloping Inisins. The presence of these 
lakes, the attitude of their shore lines and the position and char- 
acter of their discharges indicate that low elevation [irevaileil 
during the closing stages of the glacial period. The same fact is 
proved more conclusively Ity the marine deposits on the Atlantic 
coast which were contemjjoraneous with the presence of the ice. 
The facts under this head are too familiar to require more than a 
passing reference here. 
In the sketch thus far. 1 have followed the phenomena of the 
Mississippi basin because the drift is there deployed so advan- 
tageously :ui(l because its indications seem so conclusive, liut the 
phenomena on the Susciueliauna and Delaware rivers, as lnonght 
(mt by the studies of Lewis. .Mcdee. Salisbury and others, as 
well aA our own. testify to a like general fact, though in far less 
detail. The ealier glacial deposits there, as in the .Mississijjpi 
valley. api)ear to have been accompanied by less vigorous drain- 
age and to luivc been coincident with t he sultmergence of the 
coast regicjn. The later deposits were accompanied by somewhat 
more vigorous drainage than the present, precisely as in the 
Mississij)])! \;dlcy. luit the ghicial strcnnis were tiici'c also deposit- 
ing streams, and the plicnonicnn do not seem to mc to indicate 
