1892.] NATURAL SCIENCES OF PHILADELPHIA. 477 



East of the Blue Ridge I was joined by Professor A. A. Wright, 

 who had been spending the summer at Flemington, N. J., and who 

 at my request had been giving attention to the deposits near by, at 

 High Bridge and Pattenburg. Hence I will begin with the conclu- 

 sions concerning those deposits so fully described by Professor 

 Salisbury and classed by him as glacial. And certainly at first 

 glance they do look enough like glacial deposits to " deceive if it 

 were possible the very elect." That in this case it is possible, I 

 think is proved by the fact that they have probably deceived Pro- 

 fessor Salisbury. As described so well by him (N, J. Geol. Sur. 

 1891, p. 103), these deposits show only slight signs of stratification, 

 and contain, mingled through the clay to a depth of from ten to thirty 

 feet, many boulders large or small, some of them several feet in diam- 

 eter, and most of them partially rounded. There are also many 

 smaller fragments of slate, nearly all of which are scratched. One 

 well scratched fragment, about two feet long and one and a half 

 wide, was observed well scratched on one side. At Pattenburg also 

 we found two or three of the boulders of harder rock somewhat 

 scratched. But such are very rare, and the rounding was not 

 quite characteristic of a glaciated region. 



A noticeable, and I believe, a crucial fact in determining the 

 character of the deposit, is that the material is local. The boul- 

 ders are all of a gneissoid character, such as compose the mountain 

 which in both places rises several hundred feet above the deposits 

 directly to the north, and down which boulders of the same sort are 

 creeping in majestic array in every direction. I did, however, at 

 High Bridge, note one small pebble which was possibly Potsdam 

 sandstone. Furthermore these mountain flanks were doubtless once 

 covered with strata of limestone and slate, such as are still found in 

 close proximity in the synclinal basins which have escaped erosion. 

 Hence it is possible, if not probable, that the fragments of slate are 

 the remains which have escaped absolute destruction by the erosive 

 agencies which have been so long at work in this whole region. 

 The scratches might well have been made in the process of creeping 

 down the disintegrating mountain side, which secures almost exactly 

 the same mechanical forces as the movement of a glacier does. 

 Creep scratches engaged the attention of Professor Lewis and 

 • myself at the outset of our investigations in Pennsylvania in 1881, 

 and are discussed at considerable length both on p. 96 of vol, Z, in the 

 account of phenomena at Hickory Run, in Carbon County, and in 



