296 H. L. FAIRCHILD POST-GLACIAL SUBMERGENCE OF LONG ISLAND 



The absence of boulders on the plain, while abundant along the mo- 

 raine, was by Lewis attributed to disintegration. But postglacial weath- 

 ering has not been more effective on the plain than on the moraine. 

 A¥ith the subaerial theory we should expect coarse material and even 

 boulders along the stream channels. Under submergence we might ex- 

 pect them; to be rafted out on the plain by floating ice. The probable 

 explanation is that the waves prevented ice-blocks from voyaging far 

 from shore, while the underflow by stream or tide was not competent to 

 move large stones far from the beach. We do find cases of ice-rafting in 

 the secluded waters, which will be described later. 



SUBMERGED MORAINES 



No writer appears to have recognized the striking difference in the 

 surface expression of the moraines. Montauk has good moraine relief, 

 being part of the outer moraine belt ; but the hills are rounded, softened, 

 subdued, and very unlike the moraine at Bridgehampton or the hills 

 along the north side and west end of the island. This subdued character 

 pertains also to the Shinnecock Hills. It is found that these subdued 

 moraines have been cleared of forests, while the rough moraines are left 

 in timber. The explanation of this difference in the moraine surface is 

 found in the fact that the cleared hills with softened outlines were be- 

 neath the marine waters. This is indicated in the map. The theoretic 

 marine plane clearly separates the smoothed, lower moraines from the 

 higher and rough, unsubdued moraines. 



The sandy or somewhat duny surface of the Shinnecock Hills, noted 

 by the early writers, was doubtless an effect of their submergence. It is 

 possible that part of the sand might have been derived from Shinnecock 

 Bay, but if so the work should be in progress today. The Montauk Hills 

 will probably show some stratified sands in the hollows. Fuller says : 



". . ., a mantle of dune sand materially altering the surface relief of the 

 Shinnecock, if not of the Montauk Hills. The former were covered with drift- 

 ing sand hills when visited by Timothy Dwight as late as 1822" (page 35). 



Fuller selects as special examples of the very diversified morainal to- 

 pography the high, detached and unsubdued hills east of Manorville. 

 north of East Quogue, and between Hampton Park and Sag Harbor 

 (page 33). These are the only portions of the earlier moraine in the east 

 end of the island which stood above the sea. Just between the East 

 Quogue and the Hampton Park Hills lies the Shinnecock group, a well 

 developed part of the same outer moraine, l)ut with strikingly different 

 expression. If -^U the island and the moraines stood above the sea, then 



