LOBEGK, NEW YORK CITY, A PHYSIOGRAPHIC CENTER 



13 



of the Cascades, and Castellated Ridge. Note, too, how all of these fea- 

 tures are concentrated on the north and east side of the range. Most of 

 these ravines show the characteristic trough-form of glaciated valleys, but 

 the example par excellence in the White Mountains is Crawford Notch 

 (Fig. 7), which for true charm of outline can hardly be equaled even in 

 the well known glaciated mountains. In the Adirondack Mountains 

 Lake George lies on the floor of a glaciated trough of superb beauty (Fig. 

 23) and several of the finger lakes of western New York occupy similar 

 valleys of rounded profile. 



In developing the subject of continental glaciation the teacher refers 

 to the terminal moraine (Fig. 8) with its characteristic knob and kettle 



Fig. 9. — The largest erratic on Long Island and one of the largest in the eastern 



United States 



It is a mass of crystalline rock carried in the ice sheet from New England over 



Long Island Sound 



topography so easy of access on Staten Island, its continuation across the 

 "Narrows" into Prospect Park, Brooklyn, its bifurcation further east 

 where two terminal moraines form the backbone of Long Island and its 

 fish-like tail at its eastern end, and then on into Block Island, Nantucket, 

 and Marthas Vineyard. Westward in New Jersey it may be seen in rather 

 classic perfection at Plainfield and at Hackettstown. 



The lobate form of the ice front is shown by the festoon-like trend of 

 the moraine in New Jersey (Fig. 29) and in Marthas Vineyard. Then 

 there is the great outwash plain fringing the southern side of Long Island 

 and the islands to the east. The city of Plainfield, New Jersey, stands 

 upon such a plain, whence it derives its name. The contrast between 

 glaciated and non-glaciated areas, the difference in soil, the disturbed 

 drainage, the rapids and waterfalls and numerous lakes in one case, their 



