PLEISTOCENE GEOLOGY OF NASSAU CO. AND BOROUGH OF QUEENS 627 



A borrow-pit in the southwestern part of the village of Oyster 

 Bay showed beds dipping southward 26°, an angle not far from 

 that of fore-set beds in delta structure. These beds were overlain 

 by other sands in horizontal beds, and the whole appears to be a 

 portion of the normal section of the lower part of the series. This 

 section lies between 40 feet and 50 feet above sealevel. There is 

 nothing in the attitude of the beds at this locality to indicate that 

 the strata were disturbed after deposition, as is the case on the 

 contrary in so many of the bluffs along the north shore. Another 

 good exposure occurs in Cooper bluff between Oyster Bay and 

 Coldspriug harbors, in the cliff on the south side of Oak neck near 

 the wharf, and at Barker point. 



The houlder clay hed. In many of the coastal sections on the 

 north shore an unstratihed mixture of pebbles, sand and clay in a 

 bed varying from 3 to 10 feet in thickness may be seen in a posi- 

 tion to indicate that it is interstratilied with these older gravels; 

 but it is only in the sand pits on Hempstead bay that a bed of this 

 character is fully revealed. About half way up the bluff, or about 

 100 feet above the bay, there is a bed of boulder clay from 2 to 3 

 feet thick, traceable in all the pits open in 1900 south of Bar beach. 

 The matrix of this bed is an unctuous dark blue clay locally sandy 

 or gravelly. Scattered through it and sometimes in close contact 

 with each other are glaciated boulders often over 1 foot in diameter 

 and numerous pebbles attesting the glacial origin of the deposit. 

 Several large boulders examined in 1901 by Dr F. J. H. Merrill 

 and the writer were recos^nized bv the iirst named as havino- been 

 transported in all probability from the Adirondacks. Other small 

 boulders carrying Silurian fossils indicated their origin in the Hud- 

 son valley north of the Highlands. The longest journey made by 

 these materials appears to exceed 200 miles.^ 



The bed rests evenly and smoothly on the underlying gravelly sands 

 without marked disturbance or erosion. This relation to the under- 

 lying bed suggests the dropping of stones and clay from overlying 

 floating ice more than the actual advance of an ice sheet on this part 



^ Mather reported finding in the valley of Schoharie kill, boulders with "opales- 

 cent feldspar like that of Essex county " and referred them to parent ledges in 

 the eastern Adirondacks. Geol. rep't. 1843. p. 187. 



