often crop out. The composition and textural properties of the surficial 

 layer suggest that it is derived from erosion and reworking of the pre- 

 Holocene substrate. 



Below the surficial sediments are diverse sediment deposits ranging from 

 organic-rich mud to gravel. Many are thin bedded and appear to have little 

 lateral extent. Few of these deposits contain mollusk shells and shell 

 fragments or other calcareous organic particles. Some are yellowish brown, 

 which suggests that they may have been deposited in a subaerial setting or 

 have been exposed to leaching subsequent to their deposition. The hetero- 

 geneous character, extremely poor sorting, and oxidation type color of the 

 coarser subsurface deposits, as well as the presence of channellike sub- 

 bottom reflectors on the seismic records, suggest a fluvial origin. 



III. POTENTIAL BORROW AREAS 



Analyses of the geophysical records and vibracores identified 15 poten- 

 tial borrow areas where sand judged suitable for beach nourishment may be 

 recovered. The areas are identified by letters A to in Figures 8, 9, 

 and 10. Tables 3 and 4 provide a summary of the pertinent information for 

 the 15 borrow areas. Volume calculations were made for the Holocene marine 

 sand deposits where seismic reflection and topographic control were suffi- 

 cient for a reasonably reliable estimate. In addition, 10 cores at isolated 

 sites contained suitable sand but additional data are needed to fully evalu- 

 ate them. Table 5 contains data on these sites, identified by core number, 

 where the specified core recovered potentially usable sand from deposits 

 which were not associated with any discernible topographic or seismic reflec- 

 tion features. For this reason the core data could not be projected beyond 

 the immediate area of the core site and no area or volume calculations could 

 be made. Some of these sites contain Holocene marine sand (type A) which 

 does not seem to be associated with a prominent shoal. The remaining sites 

 contain type E or F material which is thought to be pre-Holocene fluvial 

 sediment. 



IV. SUMMARY AND RECOMMENDATIONS 



Approximately 1800 square kilometers of the central New Jersey shoreface 

 and Inner Continental Shelf was surveyed, using several seismic reflection 

 devices and a total of 97 vibratory cores to locate and quantify sand 

 resources suitable for use as fill in nourishing recreation beaches on the 

 adjacent barrier islands. Study results show that a large number of linear 

 and arcuate shoals are present which contain large volumes of clean quartz 

 sand. Most of the shoals appear to be Holocene to modern in age and to over- 

 lie a substrate of pre-Holocene sedimentary deposits which are fluvial in 

 origin and exhibit characteristics of past subaerial erosion. It is esti- 

 mated that about 172 million cubic meters of suitable sand from 15 potential 

 borrow sites is present. In addition, 10 other sites were found to contain 

 suitable material, but there are insufficient data on these sites to project 

 the deposit beyond the core site or to estimate volumes available. Addi- 

 tional data are required to evaluate these sites. 



A very important consideration that was not addressed in this report is 

 the possible adverse effects of removing sand by dredging from shoreface 



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