14 . PROCEEDINGS OF MADISON MEETING. 



determination, it was decided to take for criteria Oriskany pebbles and bowlders, 

 as that formation is generally fossiliferous along its outcrops to the north, and is so 

 different from the Potsdam as to be readily distinguished from it at all stages of 

 weathering, even when destitute of fossils. The presence of this rock would be an 

 evidence of transportation, and when higher than 450 feet above tide (the \evel of 

 the Columbia formation) would be evidence of the presence of ice or of the former 

 occupancy of the region by Oriskany, The latter condition is so evidently impos- 

 sible, when the position of the outcrops is studied, that it would be safe to attribute 

 to ic'e the presence of such finds, especially if water- worn or glaciated. 



The north side of the South mountain is deeply weathered, and in a cutting for 

 the South Bethlehem reservoir extends over 20 feet below the surface. It is seldom 

 that the gneiss is found at the surface in place. On this side of the mountain there 

 were few evidences of transportation found, but these extended to the height of 

 600 feet above tide. Dropping the work on this side, Ihe south side was examined, 

 and there large masses of Oriskany were found, as well as typical masses of Oneida 

 conglomerate. These were found mixed with Potsdam and gneiss as far south as 

 a line through the second railroad cut south of Bingen station to the house of Cap- 

 tain Eudy near the most northern of the zinc mines at Friedensville, and south of 

 this line nothing of the kind has thus far been found. On the contrarj^, the sur- 

 face is generally free from everything but the rocks of the formation lying beneath 

 and exhibits these rocks in more or less weathered conditions. North of this line 

 four lines of rocks, more or less continuous, were found that were generally parallel 

 to one another. The second from the south has been traced from the hill just 

 north of Leithsville to the top of the elevation one and one-half miles west of 

 Seidersville, where the barometer shows over 700 feet above tide. In these lines 

 there are stones of all sizes, from small pebbles to bowlders several feet long, and 

 in some places Oriskany is abundant. 



This work is to be continued next fall, when an attempt will be made to trace 

 the fringe over the mountain to the Lehigh valley. As it is, however, but 10 feet 

 thick at best in the valleys, it may be impossible to do this in a satisfactory manner. 

 This preliminary notice is to call attention to the fact that the area of direct glacia- 

 tion is extended 22 miles to the southward of the great moraine— this is, about the 

 distance of the Pattenburg, New Jersey, deposits from the same — and that a line 

 through the New Jersej^ places extended to the points studied would be parallel to 

 the great moraine. As the Saucon is a closed valley to the south, it is proposed to 

 see if any evidences are left of beaches in the small lake formed when the ice shut 

 up the northern opening. This will require a more careful survey than has thus 

 far been attempted. 



Finally, there has been found a patch of Potsdam on the mountain back of 

 Seidersville, extending from a point about 150 feet east of the road to Bethlehem 

 for a quarter of a mile eastward and at a height of 640 feet above tide. This shows 

 that the outcrop, as marked on the map, must be revised. 



Since writing the above it has been possible to put a few more days upon the 

 field to settle the following points : 



1. When the ice crossed the range on the road from Bethlehem to Emaus it 

 removed the old soil and the undecomposed gneiss is now within a few inches of 

 the surface. The covering seems to be foreign, as a few flakes of quartzite were 

 found in it. The lower flanks of the same spur at the new South Bethlehem reser- 

 voirs show over 20 feet of decomposed gneiss. 



