Plate 9 



SKETCH MAP OF 



A PART OF LONG ISLAND 



SHOWING 



PROBABLE POSITION OF RETREATING ICE-FRONT 



AT PORT WASHINGTON AND COLLEGE POINT 



STAGES or DELTA BUILDING. 



Tine map includes the area from Roslyn and Glen Cove on the east to Brooklyn and from the moraine to the north shore. The obliquely ruled black lined ai-eas comprise 

 lamd above the 100 toot line. The unruled area between the morainie and the heavy black line representing the Port Washington ice front gives the approximate extent of 

 the fresh-water lake held in at the Port Washington stage. The dotted surface with lobate margins shows the position of the delta of that stage, and the arrow indicates 

 the channel through which the Hempstead bay lake drained into Manhasset bay lake, from which in turn the water may have escaped Into the Little Ne«k and Flushing bay 

 regiom, and so spilled over the monaine In some one or more o£ the low passes marked by small arrows. 



