taken for foundation engineering studies for Coast Guard navigation buoys 

 in the Bight. These indicate that gently southeast dipping Coastal Plain 

 Strata underlie the Shelf off the Harbor. Shrewsbury Rocks, extending 

 offshore from Long Branch, N.J., (Figure 3) mark the physiographic and 

 geologic demarcation between deeply eroded Upper Cretaceous strata to 

 the north and evenly truncated Tertiary Strata to the south (Figure 7) 

 (Williams and Duane, in press). 



Overlying the Coastal Plain sediments are sands, gravel and fine 

 detritus which in part owe their origin to the ancestral Raritan and 

 Hudson Rivers which flowed over the exposed Shelf during Pleistocene time. 

 Additional material from melt water erosion of the terminal moraines of 

 Long Island was deposited concurrently on the Shelf, ICONS geophysical 

 records east of Sandy Hook Show an elongate area containing complex sets 

 of cross stratified Pleistocene sand and gravel up to 75 feet thick on 

 top of deeply eroded Coastal Plain strata. The crossbed sediments are 

 overlain by flat lying stratified sand with an average thickness of 15 

 feet (Williams and Field, 1971). 



Stratigraphy of the sediments of the Inner New York Bight in the dump 

 grounds follows: 



Upper Cretaceous and Tertiary strata (sands, silts, clays and some 

 gravels) form the base material of the Shelf of the Bight. Pleistocene 

 glaciofluvial material was deposited unconformably upon the erosion 

 surface represented by these sediments. In certain areas of the Bight, 

 especially near ancestral river beds, east of Sandy Hook these sediments 

 are crossbedded. Superimposed on the Pleistocene sediments are horizontal, 

 sand deposits of variable thickness of Holocene age. Subbottom profiling 

 and coring studies indicate the existence of a thin veneer of Holocene 

 material near the dumping grounds. This material is covered by dredge 

 spoils and sewage sludge. Ambiguity persists about the thickness of the 

 waste materials on the present dumping grounds. Random core sampling in 

 this area has shown accumulation of waste sediment having thickness of 

 only a few centimeters. One core showed waste thickness of about one 

 meter. This core, it is believed, was taken in a topographic low where 

 such accumulation is more probable. The apparent absence of a thick 

 accumulation of waste material on the ocean floor as revealed by ICONS 

 cores and geophysical records indicates either resus.peinsion and transport 

 of this sediment or rapid biodegradation. Such a magnitude of bio- 

 degradation may be more true for the sewage sludge which has a higher 

 organic content in contrast to excavation rubble or dredge muds. 



c. Surface Sediments . A large percentage of the sediments found in 

 the designated dredge spoil dumping area originate from dredging and 

 maintenance of navigation channels in the Harbor. These channels are 

 dredged to accommodate the large volumes of shipping into the Harbor. 



Sediments of the Inner Harbor are generally fine grained sands and 

 silts subject to continuous shifting by bottom currents. In the outer 

 part of the Harbor, including Sandy Hook Bay, the bottom is typically 



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