Kummel — Glaciation of Mountains in Pennsylvania. 113 



Akt. XIY. — Note on the Glaciation of Poeono Knob and 

 Mounts Ararat and Sugar Loaf Pennsylvania / by 

 Henry B. Kummel, Ph.D. 



[Published by permission of the State Geologist of New Jersey.] 



During the past field-season an opportunity was given me, 

 in connection with my work on the glacial deposits of Northern 

 New Jersey, to visit Poeono Knob, Monroe County, and Mounts 

 Ararat and Sugar Loaf, Wayne County, Pennsylvania. The 

 Pennsylvania State geologists* have held that during the gla- 

 cial period these peaks were nunataks. 



Poeono Knob is an outlier of Poeono Plateau, situated about 

 nine miles northwest of Stroudsburg. The terminal moraine 

 is well developed on its north and south flanks, about two-thirds 

 of the way up the slope. Since this knob was examined by 

 Lewis and Wright, a wagon road has been constructed up the 

 northwest side and along the top of the hill for more than half 

 a mile. This road affords almost continuous exposures to a 

 depth of from one to three feet, along the top of the knob. 

 Here was found a considerable variety of material, chiefly shales 

 and sandstones of different color, texture, and lithological con- 

 stitution, with some coarse conglomerate. Not a few of these 

 had been worn to subangular form with more or less well 

 marked planation surfaces. Fragments bearing striae, of 

 whose origin there can be no doubt, are not abundant, but ten 

 or twelve cobbles were found, which bore unmistakable glacial 

 scratches. Some of these occurred not more than thirty feet 

 below the summit. The evidence is conclusive that the ice 

 covered the western part of the hill to within at least thirty 

 feet of the highest point. That it also covered the crest is 

 very probable. 



When one leaves the road and examines the weathered 

 material on the surface, hidden, as it is, by vegetation, it is 

 next to impossible to convince oneself, that there is any glacial 

 debris on the knob, and during the earlier part of my investi- 

 gation, before I had examined the exposures along the road, I 

 held the same opinion as those who had earlier studied the 

 ground. 



On the highest point of the hill, the surface is strewn with 

 large bowlders of disintegration, and the ledges show no signs 

 of glacial action. No evidence of glaciation could be found on 

 that part of the hill which lies east of the summit, where there 

 are no exposures, but in view of what was found along the 

 road, where the opportunity for observation is good, there can 



* Lewis, Second Geological Survey of Pennsylvania, Terminal Moraine, Z, pp. 

 75, 271. White, idem., Susquehanna and Wayne, G5, pp. 25, 159. 



Am. Jour. Sci. — Fourth Series, Yol. I, No. 2. — February, 1896. 



