1889.] 
397 
[Davis and Wood- 
25. Revived Streams. The 
Musconetcong, fig. 7, 1 follows a 
remarkably straight southwesterly 
course for forty miles, from its head 
in the centre of the Highland pla- 
teau to the Delaware a little below 
Easton. The branch that carries 
the overflow of Lake Hopatcong to 
the main stream is very likely a 
post-glacial tributary, and is omit- 
ted from the figure ; with this ex- 
ception the Musconetcong basin is 
hardly over five miles wide ; all of 
its side streams are short, and 
nearly all of them have a direct 
course down the slopes of the en- 
closing mountains to the main 
stream. These mountains are of 
resistant gneisses and schists, while 
the longitudinal valley is excavated 
along a synclinal band of limestone. 
This example is the very ideal of a 
valley cut out by a revived stream 
wdiose course had been finally ad- 
justed in a previous cycle to the 
structure of the old land that it 
channelled. Its relation to the 
long lost constructional form of the 
land cannot now be deciphered. 
valleys being clearly apparent. The great 
area drained by the Raritan and the Passaic, 
with the little Rahway between them, is left 
unshaded. 
The line of heavy dots from the Ramapo to 
the Musconetcong marks the southeastern 
border of the Highlands; a lighter dotted line 
from the Assanpink to the mouth of the Rar- 
itan is the approximate position of the fall- 
line; and a dotted line running southwest from 
the Atlantic coast indicates the vague north- 
ern border of the southern lowlands. 
1 Fig. 8 (see p. 398) is a guide to show the 
locations of fig. 7 and several others in their 
appropriate parts of the state. 
