The location and shape of these hills formed in the Tertiary must be judged from the posi- 

 tion of the upper surface of the Cretaceous sediments as revealed in well records. In a general 

 way this surface corresponds with the present topography, although the surface today is every- 

 where higher because of the blanket of glacial deposits which covers the older formations. In 

 eastern Nassau and western Suffolk counties, the tops of the buried Tertiary hills are now en- 

 countered in well drilling at an elevation of about 200 feet above the present level of the sea. In 

 these areas the present land surface lies about 300 feet or so above sea level. To the west, both 

 the former and the present land surface are lower, so that in the central part of Nassau County 

 the Cretaceous beds extend no higher than 50 to 60 feet above sea level. Along the western 

 boundary of Nassau County, and in a relatively broad belt running west through the north- 

 central part of Queens County, the surface of the Cretaceous is about at sea level and slopes 

 off gently to the north and south. This surface merges with the surface of the bedrock in the 

 vicinity of Astoria in northwestern Queens County, and cannot be traced beyond this point. 



The configuration of the Cretaceous surface in northern Queens has been the subject of 

 considerable speculation. It has been the opinion of a number of the early students of Long 

 Island geology (9, 11, 15) that a river, the so-called Sound River, which eroded the depression 

 now occupied by Long Island Sound, once flowed from east to west. In Northern Queens, some- 

 where in the vicinity of Bayside or Flushing, it is imagined to have turned south, passing 

 through southwestern Queens or eastern Kings Counties and reaching the sea somewhere south 

 of Jamaica Bay. The headwaters of the Sound River are believed to have included the Housa- 

 tonic and probably also the Connecticut Rivers or the ancestors of these streams. The reasons 

 for believing that this drainage turned west rather than east along the lowland that is now 

 Long Island Sound are not strong. The Delaware, the Susquehanna and the Potomac Rivers 

 have been deflected to the south and west where they cross the weak beds of the basal Creta- 

 ceous and the reasons advanced to explain this coincidence are used as arguments to show that 

 the Sound River must have done likewise. Of more force in suggesting a drainage to the west 

 have been the well records which reveal segments of buried valleys believed by some to be the 

 former channel of the Sound River. In southern Kings County for example, a valley roughly 

 half a mile wide and 75 to 100 feet deep has been found cut into the upper surface of the 

 Cretaceous beds and another similar segment of a buried valley has been observed in south- 

 central Queens. 



The Cretaceous surface in these places is about 200 feet below sea level and the bottoms 

 of the supposed valleys are about 100 feet deeper. There is however, no proof that these valleys 

 ever carried the drainage of the Sound River. The valley segment in Kings County is poorly 

 outlined even in the two or three miles near the center of the County where it is most clearly 

 defined by well records. Attempts to trace it to the northeast into Queens County are blocked 

 by a lack of data, and it is impossible to say whether it connects with the depression of Long 

 Island Sound or not. However, available well records in the central and northern parts of 

 Queens County do not show any valley in the Cretaceous surface reaching to 300 feet or so 

 below sea level, but the spacing of the wells in this area is such that it is barely possible that 

 the valley may exist, but has been missed by existing borings. This remote possibility is a 

 poor reason for believing that a connecting link exists between the Sound, and either or both 

 of the buried valley segments to the south. A simple explanation is that they were carved by 

 drainage that originated on the exposed surface of the Cretaceous sediments at the same time 

 that the Long Island Sound depression was being formed by eastward flowing streams. If this 

 were the case the valleys would head at the former divide in north-central Queens County. The 

 extent and distribution of these valleys is a matter of importance for they were later filled with 

 beds of coarse sand and gravel, the Jameco gravel, and so form one of the important 

 sources of water in western Long Island. 



The data so far available do not yet permit a reconstruction of the drainage pattern 



38 



