768 A. C. VEATCH 



possible, leads us to believe that a like number of records on 

 Long Island would show a like irregularity. 



The pre-Pleistocene unconsolidated beds, represented by sands, 

 gravels, and clay, for the most part Cretaceous, outcrop at many 

 points on the north shore and in the West and Half Hollow 

 Hills. Well sections show that they are present at no great 

 depth under the glacial material in the highest part of the 

 island, and they are now known to form a core about and over 

 which the Pleistocene beds have been deposited. Although 

 involved in sharp folds in many of the bluffs on the north shore, 

 this folding does not appear to extend to any great depth, and 

 the beds in the higher hills are essentially erosion remnants with 

 a small coating of glacial material. On the north shore, between 

 Peacock Point and Lloyds Neck, a number of wells, having a 

 depth ranging from 200 to 500 feet, show a very regular dip of 

 about 65 feet per mile S. 20° E., which contrasts markedly with 

 the crumpled condition of the beds at the surface above them. 



The preliminary map (Fig. 4), showing the approximate 

 surface of the pre-Pleistocene unconsolidated beds, as far as 

 they are known from well sections and outcrops, emphasizes two 

 points: (i) the presence of a deep valley passing beneath 

 Jamaica and Jamaica Bay, with a maximum depth exceeding 280 

 feet below present sea level, which seems to be the logical con- 

 tinuation of the deep channel shown by the soundings of the 

 Coast and Geodetic Survey off New York harbor; and (2) the 

 fact that the older deposits form the greater part of the highest 

 points on the island. 



All these beds, so far as known, are Cretaceous, with the 

 exception of a thin bed of "fluffy sand " in the top of the West 

 Hill section, which Mr. G. N. Knapp has referred to the Miocene 

 because of its lithological resemblance to some of the near-by 

 New Jersey beds. 



Pensauke?i. — The oldest of the Pleistocene deposits on Long 

 Island are coarse yellow quartz gravels, which contain a few very 

 much weathered compound crystalline pebbles and cobbles. 

 They are found capping West Hills and underlying the Wiscon- 

 sin moraine in the Wheatley Hills at no great depth. In the 



