10 



PROCEEDINGS OF MADISON MEETING. 



in Triassic times. These rounded pebbles have been weathered out of their un- 

 stable red matrix in great numbers, probably in both preglacial and postglacial 

 times. They reach a size of three inches commonly, but still there are plenty of 6 

 and 12 inches and some of 15 inches. Not infrequently in the vicinity of streams 

 we find these pebbles redeposited with clay and sand in unstratified masses closely 

 resembling glacial till. There are other deposits of these same materials, however, 

 which are doubtless glacial, and some of them may be characterized by angular 

 fragments of gneiss from the mountains northward, which have never been im- 

 bedded in the Triassic conglomerate. On account of the difficulties just described 

 the points upon the boundary which are given west of Cushetunk mountain may 

 not have been determined with entire precision, but they are believed to be nearly 

 correct. 



Del. Water Gap 



PENN 



Figure l.—Map showing Limits of the glaciated Area in New Jersey. 



The first point is one-half mile south of Allerville ; the second is a mile west of 

 the first and a mile east of Landsdown; the third is at Sidney, a mile southwest 

 of Landsdown ; the fourth is at King's mill or Kingstown, and includes the hills 

 north of Pittstown, but excludes those to the southeast and southwest of Pitts- 

 town ; the fifth and sixth are about a mile south and southwest respectively of 

 Midvale. This last station is at an altitude of 600 feet above tide, and, although 

 still upon the Triassic, is not greatly lower than some of the passes upon the 

 Archean ridge of Musconetcong mountain. The line doubtless passes south of 

 Pattenburg and north of Little York, crosses the Musconetcong ridge at the altitude 

 of 760 feet southwest of Bloomsbury, lies high upon the northwestern flank of the 

 Musconetcong south of Hughesville, and reaches the Delaware river in the vicinity 

 of Riegelsville. More detailed work may yet be profitably done in determining 

 the distribution of the drift upon Musconetcong mountain west of Pattenburg. 



