644 CHARLES EMERSON PEET 



coalesce, either (i) they did coalesce or (2) the outlets had been cut 

 enough to so lower the water-level of each that they remained inde- 

 pendent. If the lakes coalesced, then either (a) one of the outlets 

 had been cut lower than the other, and thus rapidly drew off the 

 water below the level of the other, or (b) both persisted and were 

 rivals in the task of draining the lake. 



In order that the requirements of the situation be clearly under- 

 stood reference must be made to the maps showing the gaps and their 

 relations to the present channels (see Fig. 8, p. 427, and Fig. 7, 

 p. 425). From these maps it is observed that the Arthur Kill gap opens 

 southward from Newark Bay, and that the Narrows gap opens 

 southward from New York Bay. Newark Bay and New York Bay 

 are connected by Kill van Kull ten miles north of Arthur Kill gap. 

 New York Bay is connected with Long Island Sound by East River. 

 The east end of Long Island Sound opens to the sea by wide channels. 

 The land on the sides of both Kill van Kull and East River seems to 

 indicate that the channels which they occupy have not been cut from 

 much above sea-level. It follows, therefore, that if Arthur Kill and 

 the Narrows gap were cut at first as outlets of independent lakes at 

 the ice-front, and later as rival outlets of a water body that covered 

 Newark Bay and New York Bay, they must either have been cut 

 below the level of the divide between Long Island Sound and New 

 York Bay before the ice retreated beyond it, or the present gap at 

 the east end of Long Island must have been closed by a higher alti- 

 tude of the land. Otherwise the Narrows gap at least would have 

 been abandoned for a lower channel into Long Island Sound. While 

 it is not at all unlikely that the gap at the east end of Long Island 

 was closed, it is not essential for our present purpose to assume this. 

 The writer, however, beheves that the hypothesis that the present 

 gap at the eastern end of Long Island was closed at that time by a 

 greater altitude of the land is as tenable an hypothesis as any to account 

 for the water body in which accumulated the recent clays of the Con- 

 necticut Valley and other valleys opening into Long Island Sound. 

 It is in harmony with the pubhshed facts in regard to the distribution of 

 those clays. ^ However, this is aside from the point under discussion. 



I See N. S. Shaler, J. B. Woodworth, and C. F. Marbut, "Glacial Brick 

 Clays of Rhode Island and Southeastern Massachusetts," Seventeenth Annual Report, 

 U. S. Geological Survey (1895-96), pp. 957-1004. 



