1878.] 



85 



A glacial moraine may be traced from the Wind Gap in the Kittatinny 

 Mountain through Ackermannville, Bangor and Williamsburg to Portland 

 on the Delaware River. Crossing the river at this point it extends across 

 New Jersey on to Long Island. This Moraine exhibits the hummock sur- 

 face so common to glacial moraines everywhere ; sometimes it contains 

 peat beds ; is often forty to sixty feet high, and is the cause of the marshy 

 deposits so frequent in that portion of the country. Being easily cultivated 

 and the soil quite productive it is usually cleared and cultivated. 



West of the Wind Gap no glacial moraine can be seen as far as the 

 Lehigh River. That it has existed, however, there is but little doubt and 

 was probably washed away again by aqueous, action to be re-deposited as 

 modified drift over most of the limestone portion of the country north of 

 the Lehigh, covering the limestone and rendering its structure difficult to 

 determine. This modified drift is quite prominent at two points ; one 

 being on top of the hill where lies West Bethlehem, the other at Easton, in 

 what is called West Ward, both at a height of about 320 feet above tide- 

 level. At West Bethlehem the drift is distinctly stratified, consisting of 

 alternated layers of sand and pebbles or small boulders. At Easton, how- 

 ever, such a bedding is not so distinct. 



The fact that both of these deposits occur almost at the same level, would 

 seem to indicate that they had been deposited cotemporaneously by the 

 same action, either fluvintile or due to a subsidence. 



Another glacial moraine also exists in the Saucon Valley south of the 

 Lehigh, it extends from Friedensville almost to Bingen station on the 

 North Pennsylvania Railroad. 



No trace of glacial action has been as yet noted in the Laurentain rocks 

 forming the South Mountain in Northampton county, and the glaciers 

 either passed around them or going over left no trace of their course. The 

 former being probably the case. 



In the discussion which followed Mr. Lesley added the 

 following facts which touched upon the now so widely 

 mooted questious relating to the Drift phenomena of the 

 United States : 



He remarked that there were similar isolated patches of gravel, each 

 several hundreds of acres in extent, lying on the level upland of Delaware 

 and Chester counties, south west of Philadelphia, and that these patches 

 have about the same elevation above tide, say 350 feet. 



The uppermost or gravel terrace along the north-west side of the valley 

 of the Delaware River, the remains of which have been traced by Mr. 

 Lewis, of Germantown, all the way from Wilmington, in Delaware, north- 

 ward through Chester count}- and the Fairmount Park, half way to Tren- 

 ton, is made by recent levels taken by Mr. Lewis and Mr. C. W. Ames to 

 occupy about the same geological position. Mr. Lewis asserts that he has 



