and in some cases modes of transport and ultimate environments of deposition. (Krinsley 

 and Takahashi, 1964.) Sediment samples from several cores in the inner bight were 

 examined by scanning electron microscope (SEM) and surficial textures ascribed to glacial 

 abrasion were recognized in cores 3 and 52. (Figure 20.) Cores 1 and 6 in the study area and 

 two cores farther south had textures indicative of high energy beach conditions. (See Figure 

 21.) Some cores east of Sandy Hook contained grains exhibiting a superposition of 

 characteristic beach features on distinctive glacial markings, indicating multiple 

 environments. (Patricia Blackwelder, written communication.) The results of these 

 observations supported other data on source and dispersion of sediment shown in Figure 19. 



Color of the sediment was of little help in distinguishing glacially derived sediment from 

 Coastal Plain material. Glacial silts and fine sands are light to dark gray, depending on heavy 

 mineral abundance, and the medium and coarse sands are normally reddish brown, probably 

 resulting from oxidation of iron-bearing minerals. Coastal Plain material also ranges in color 

 from greenish gray to reddish brown. Disseminated fine-grained glauconite may be 

 responsible for the greenish cast of some samples. 



The sediment limits shown in Figure 19 are based on the above data and are intended to 

 document only the surficial modern sediment. Some glacial material was transported farther 

 south than the boundary indicates but apparently the quantity of material carried south of 

 the Atlantic Highlands was insignificant compared to the volume of sediment contribution 

 from Coastal Plain sources. This sharp demarcation in Holocene sediment source possibly 

 can be attributed to the Hudson Channel which may have acted as an effective barrier to 

 sediment transport during Pleistocene to the present time. It must have funneled glacial 

 detritus farther out on the shelf thus accounting for a large areal spread of outwash across 

 the shelf south of New England. (Knott and Hoskins, 1968.) 



V. SAND NEEDS AND RESOURCE POTENTIAL 

 1. Sand Fill Requirements for Area Beaches. 



There are several existing and recommended Corps of Engineers Beach Erosion Control 

 and Hurricane Protection projects for parts of Long Island, Staten Island, Raritan-Sandy 

 Hook Bays and the Atlantic coast of northern New Jersey. Sand volumes needed for each 

 area, including the initial fill at inception and the estimated volumes necessary to replace 

 annual erosion over a project life of 50 years, are detailed in Table 5. Total sand needed at 

 present for federally approved projects is over 58 million cubic yards, almost 22 million for 

 initial fill and 36.6 million for periodic maintainance over a 50-year project life. (See 

 Table 5.) This volume estimate is likely to increase significantly if Sandy Hook and selected 

 beaches on parts of western Long Island are designated the Gateway National Recreation 

 Area as proposed. 



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