The field data used in this study consist of continuous seismic reflection 

 profiles and vibratory cores shown in Figure 2. The data were collected in 

 1967 under contract with Alpine Geophysical Associates, Inc., and consist of 

 700 kilometers of sparker trackline acoustic profiles and 75 cores, 9 centi- 

 meters in diameter and a maximum of 5 meters long. The lengths of actual 

 sediment recovered in the cores range from 1.3 to 5 meters. These primary 

 data were supplemented by numerous reports in the technical literature and by 

 use of the NOS 1 :80,000-scale charts. 



4. Geographic and Geologic Setting . 



Long Island Sound, one of the largest estuaries on the east coast of the 

 United States, has a general east-west orientation and is about 180 kilometers 

 long with a maximum width of 45 kilometers in the center and narrows at both 

 ends to about 18 kilometers wide. One of several basins that occupy the New 

 England part of the Atlantic Coastal Plain province, it lies at the contact 

 boundary between the crystalline Piedmont rocks and the Cretaceous Coastal 

 Plain strata. Like the other basins to the east (Block Island Sound, Rhode 

 Island Sound, Nantucket Sound, and Buzzards Bay), Long Island Sound is bounded 

 on the south by till deposits from the southernmost terminus of the continen- 

 tal glaciers which occupied the region in the Pleistocene epoch. 



The Connecticut coast of Long Island Sound is highly irregular with 

 numerous embayments, islands close to shore, and coarse-grained sandspits and 

 beaches. The coast is very rocky, dominated by Paleozoic-age crystalline 

 bedrock and glacial debris, except for Triassic-age sedimentary rocks in the 

 New Haven area. The four major rivers which drain Connecticut and flow into 

 the Sound are the Thames, the Connecticut, the Quinnipiac, and the Housatonic. 



The coast along the western half of northern Long Island is also highly 

 irregular and is characterized by 10 recessed narrow bays which extend south 

 and terminate at the Harbor Hill Moraine (Fig. 1); the eastern half has steep 

 and high bluffs composed of unconsolidated glacial sediment which comprise the 

 Harbor Hill Moraine that extends the entire length of Long Island. The 

 moraine is continuous from the eastern end of Long Island at Orient Point to 

 about Port Jefferson where it forms coastal bluffs with relief in excess of 

 100 meters that are directly exposed to wave erosion. West of Port Jefferson 

 the Harbor Hill Moraine joins with the Ronkonkoma Moraine and both extend 

 westward as a broken line of hills toward Staten Island and northern New 

 Jersey. 



5. General Stratigraphy of Long Island and Connecticut . 



Detailed descriptions of the geologic units comprising Long Island are 

 provided in Williams (1976); the units are summarized below and in Table 1. 

 Figure 3 shows that Paleozoic-age crystalline bedrock underlies Long Island 

 at depths to several hundred meters and rises toward Connecticut. Upper 

 Cretaceous-age semiconsolidated sedimentary strata that overlie the bedrock 

 surface are thin to the north but thicken southward under the Sound and under- 

 lie the Long Island mainland. The Lloyd, Raritan, and Magothy units consist 

 of both marine and nonmarine sands and sandy clays and are important as fresh- 

 water aquifers on Long Island. Tertiary-age rocks are known to be present 

 under the Continental Shelf south of Long Island but are absent on the island, 

 probably as a result of uplift and extensive erosion in Tertiary time. 



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