Thus, rising above the surface of the ocean there is an interrupted 

 chain of morainal deposits stretching from Cape Cod in Massachu- 

 setts, through Nantucket, Martha's Vineyard, Block Island, Long 

 Island, Staten Island to New Jersey, these deposits making up the 

 greater part of these islands, but, what is of more interest, not all of 

 the islands, of which mention will be made later. 



Soil. 



Restricting the discussion to Long Island, the soil up to the back- 

 bone consists of glacial drift, varying in depth. This drift has been de- 

 scribed by earlier writers to consist of two kinds : * i . Till or drift 

 proper, a heterogeneous mixture of gravel, sand and clay with boul- 

 ders ; 2. the gravel drift, a deposit of coarse yellow gravel and sand, 

 brought to its present place by glacial and alluvial action, but existing 

 near by in a stratified condition before the arrival of the glacier. This 

 yellow gravel drift, which in a comparatively unaltered condition, 

 forms the soil of the pine barrens of southern and eastern Long Island, 

 and is exposed in section, now in many places on the island, notably in 

 the sand pits outside of Prospect Park, in the cut of the Coney Island 

 Railroad and in the brick yard in Huntington. It is moreover equiva- 

 lent to and indeed identical with the yellow drift or preglacial drift of 

 New Jersey, a formation of very great extent in the state. Merrell 

 further gives us some interesting figures with reference to the thick- 

 ness of the till in various places. In the hills near Brooklyn it attains 

 its maximum depth, probably between 150 and 200 feet. In Calvary 

 Cemetery a boring showed the drift to be 139 feet deep, and Mount 

 Prospect, in Prospect Park, is probably all till and it is 194 feet in 

 height. All along the north shore the till is much thinner ; in some 

 places there is none and it averages in thickness from a few feet to 

 about six. At the extreme eastern end of the island there are mounds 

 of till from 80 to 200 feet high between Nepeague Bay and Montauk 

 Point. From a geological point of view the boulders are of interest, 

 representing as they do most of the geological ages, having been 

 brought down from New England and Canada. Underlying the till 

 on the whole northern shore is the layer of yellow gravel, which varies 

 greatly in different parts of the island. Various details of digging are 

 given by Merrell in his admirable paper so extensively quoted. 



Thus briefly recapitulating what is known of the soil of Long 

 Island, we have the following facts : A limited area of crystalline 

 rock, consisting of lamellated gneiss and schists, similar to Manhattens 



* Merrell, 1. c. 



