426 CHARLES EMERSON PEET 



lowland there are salt waters, which in their widest expanse consti- 

 tute Newark Bay. (See Fig. i, No. 5, and Fig. 7.) 



The upland surface represented by the even crest of the Palisade 

 Ridge is a remnant of the Cretaceous peneplain. The lowland sur- 

 face represents a later peneplain developed on the softer rocks of the 

 Triassic area.'' The valleys in this lowland represent erosion in 

 pre-last glacial and post-Pensauken time. The stratified drift in 

 these valleys was deposited largely by ice waters on the retreat of 

 the ice from the Brooklyn-Perth Amboy moraine. 



Below the upland surface and at the east base of the Palisade 

 Ridge is the Hudson Valley, now occupied by the waters of the 

 Hudson estuary. Along the sides of the valley and below the waters 

 of the Hudson estuary there are deposits of stratified gravels, sands, 

 and clays similar in origin to those in the lowland west of the Pali- 

 sade Ridge. 



Below the waters of the Hudson estuary and of Newark Bay 

 there are certain submerged channels which are shown in Fig. 8 and 

 will be referred to later. 



BROOKLYN-PERTH AMBOY MORAINE, 



Across the southern end of both the Hudson Valley and the low- 

 land west of the Palisade Ridge there is the massive and complex 

 ridge which forms the Brooklyn-Perth Amboy terminal moraine.^ 

 It is popularly referred to as the backbone of Long Island, and it 

 also makes the more conspicuous elevations of the southwestern part 

 of Staten Island. Through this moraine there are two gaps — one 

 at the south of the Hudson and the east end of Staten Island called 

 the Narrows, and the other at the west end of Staten Island occupied 

 by Arthur Kill. (See Fig. 8.) 



1 This is called the Somerville peneplain by Professor W. M. Davis, and the pre- 

 Pensauken peneplain by Professor R. D. Salisbury {loc. cit., pp. 114-15). 



2 See R. D. Salisbury, Glacial Geology of New Jersey, Chap. 9, and New York 

 City Folio, U. S. Geological Survey. T. C. Chamberlin, Third Annual Report, U. S. 

 Geological Survey, 1881-82, pp. 377-79 ; Warren Upham, American Journal of 

 Science, 1879, pp. 81-92 and 179-209 ; G. H. Cook and J. C. Smock, Geological 

 Survey of New Jersey, Annual Reports for 1877, 1878, and 1880. 



