South of the Terminal Moraine. 283 
the moraine crosses it, down to its junction with the Delaware, 
heavy masses of water-borne drift mark the ancient flood, and 
show that it was 200 feet in depth. Where the banks of the 
river are steep, as they generally are as far down as the Lehigh 
Gap, the drift is represented by scattered bowlders only, all 
the rest having been washed away. Just north of the gap, for 
example, at a point one mile below Weissport, I found a large 
rounded bowlder of conglomerate six feet long lying upon 
a bank of shales of VIII, at an elevation of 150 feet above 
the river. Smaller ones occur up to a height of 180 feet. 
But south of the gap, where the easily eroded slates of IIT form 
an open rolling country, large masses.of bowlders imbedded in 
a yellow brick clay cover the region on both sides of the river 
in beds sometimes more than ten feet deep. This deposit 
differs from glacial till in the rounded character of its bowl- 
ers, in the greater preponderance of clay, and in its more or less 
evident stratification. It certainly cannot be said to have “all 
the characteristics of a glacial deposit.” It overlies Hudson 
River slate which, as Mr. Hall observed, is broken and crushed 
over, though not by a superincumbent glacier. The decom- 
posed slates were naturally bent and crushed as the bowlder- 
laden flood crushed over them. Other cases could be cited at 
localities fifty miles farther south. A similar occurrence above 
the Lehigh Gap, also described by Mr. Hall, is of like character 
and origin, 
(6.) The mass of debris across the mouth of the Aquanchi- 
Cola Creek, supposed by Mr. Chance and Mr. Hall to bea 
moraine, has none of the characters of a moraine, either topo- 
graphically or internally. Such accumulations are common at 
the meeting of two drift-laden streams. The materials are 
water-worn, and the bank is leveled off by water, grates 
none of the contours of a true moraine. I could find no trace 
of glaciated surfaces anywhere in the vicinity. There is in 
fact nothing to indicate that this bank of drift is at all unusual 
or different from the other deposits along the Lehigh, which 
are the evident result of aqueous deposition. 
On the so-called “ Eddy-hill” just north of the Lehigh Gap 
I found no rounded stones or drift of any kind, and there is 
nothing to indicate that this conical hill made of Clinton red 
a has been materially modified in shape since pre-glacial 
imes. 
(7.) In a former paper" I have endeavored to show that Mr. 
Hall was mistaken in supposing that there is a glacial moraine 
in West Philadelphia. The gravel deposit at that locality is 
identical with that which occurs all along the Delaware from 
Trenton to Wilmington, and belongs to what I have called the: 
*The Surface Geology of Philadelphia and vicinity, Proc. Acad. Nat. Se., 1880. 
