PRESTON. G 5 . 159 



in pre-glacial times, were left as islands in the ice moving 

 southward and escaped the universal abrasion to which every 

 other portion of the township was subjected ; for no ap- 

 pearance of Drift or Glacial scratches can be found on their 

 sides or summits. 



The rocks of this area belong entirely to the Catslcill sys- 

 tem, unless we except the massive gray sandstones which 

 come near the summit of the two elevated peaks just men- 

 tioned. It all depends on what rocks we consider as the 

 base of the Pocono ; if the Mt. Pleasant Conglomerate be 

 taken as the base, then there are 300' of Pocono on the top 

 of Ararat peak ; but if the Pocono should properly begin 

 with the GriswoloV s Gap Conglomerate, 400' higher, then all 

 the rocks of the township belong to the CatsJcill. 



The surface is very rough and uneven and countless bowld- 

 ers of sandstone and calcareous breccia lie scattered over it 

 in every direction. 



In descending from the summit of Sugar Loaf the follow- 

 ing succession is exposed : (Fig. 44.) 



Sugar Loaf section. 



1. Summit capped with gray sandstone (2450' A. T.,) ... 20' 

 2. Concealed with many massive S.S. beds in interval, . 120' 



3. Sandstone with calcareous breccia at base, 10' 



4. Concealed, . 50' 



5. Mt. Pleasant Conglomerate, 25' 



6. Concealed, 130 



7. Sandstone, pebbly, (base 2075' A. T.,) 20' 



The Mt. Pleasant Conglomerate is a coarse massive rock, 



and contains at its base a calcareous layer filled with quartz 



pebbles, the most of which have a red or rose-colored tinge. 



- These reddish pebbles characterize this stratum of rock at 



South Knob on Elk Mt. 



Just west of Preston P. O. the outcrop of a calcareous 

 breccia is seen, and immense black boiolders of it are scat- 

 tered over the hill at an elevation of 1560' A. T. ; just south 

 of the village, another ledge of the same material is seen at 

 1600', they may possibly represent the Cherry Ridge group. 



Near Decker school-house 2 miles north from Lake Como, 

 the following is seen : 



