61y NEW YORK STATE MU8EUM 



INTRODUCTION 



Tlie term Pleistocene is used Iiere as the equivalent of Quater- 

 nary, a term which has heretofore been employed in the museum 

 reports for the period of great ice sheets. 



The Oyster Bay and Hempstead quadrangles together include a 

 l)elt about 13 miles wide extendino: north and south across Loiiir 

 Island. The area thus mapped comprises, aside from a triangular 

 area on the mainland about Mamaroneck not dealt with in this 

 report, the major portion of the towns of Oyster Bay, North Hemp- 

 stead, and Hempstead, the coast of Long Island sound from Man- 

 hasset bay on the west to Oyster Bay harbor on the east, and 

 the Atlantic shore from the eastern part of Far Rockaway beach, 

 eastward to Short beach. 



The matters considered in this report are 1) the topography, 2) 

 glacial deposits, 3) Pleistocene history, including data gathered from 

 the area on the west, 4) the post-glacial changes and processes now 

 in action. 



TOPOGRAPHY 



As the traveler from Greenport or Sag Harbor ap])roaclies the 

 western end of Long Island, there are more or less continuouslv 

 before him two low ridges, one skirting the north shore of the 

 island, the other less elevated and continuous and at a variable dis- 

 tance inland from the south shore, the two being separated first by 

 the deep embayments of the pronglike eastern end of the island, 

 and then by a broad, sandy plain, narrowing westward to the 

 eastern limits of the area with which this report is concerned. At 

 this point, near Syosset, the north and south ridges rudely coalesce. 

 The northern ridge takes a south southwesterly course, lies more 

 remote from the shore of the sound, and traverses the area so as to 

 inclose tlie southern ends of the V-shaped harbors of Manhasset and 

 (treat Neck bays. 



What appears to l)e a continuation of the soutliern ri(i«re is trace- 

 able as a series of low mounds at Locust Grove, Jericho, thence south 

 of Old Westbury, at All)ertson station, Searington, and so westward 

 to an abrupt termination at the base erf the higher, more massive 

 iiortlieni ridge just east of Lake Surprise. Between these mounds 



