2. Filling of the trap was generally slower than for earlier dredge and 

 fill cycles. Filling was in response to a series of "pulses" of updrift 

 sediment influx whose intensity and duration did increase toward the end of 

 the study. 



3. Sediment generally entered the trap along the nearshore with finer 

 fractions then distributed offshore resulting in final textural patterns simi- 

 lar to those characterizing an open coastline. 



4. Textural patterns of the trapped sediments indicate that depositional 

 processes in the trap were sufficient to transport grain sizes present in 

 native beach sediments. 



5. Both core sampling and surface grab sampling through time proved to be 

 adequate for describing the composite texture of trapped sediments. Both 

 methods work because of the rather simple filling history of the trap. 



6. Grab sampling through time appears to be the best sampling technique 

 for characterizing native beach sands. Core sampling proved inadequate for 

 describing beach sediments because abundant storm-lag deposits bias sediment 

 texture toward a too coarse and too poorly sorted beach composite. 



7. Textural comparisons of beach and trap sediments, using techniques for 

 polymodal interpretation, suggest that extreme storm conditions are needed to 

 transport only about 10 percent of the sediments deposited in the trap. 



8. Beach-fill calculation comparisons also indicate core sampling of 

 native beach sediments to be an easily biased and potentially misleading data 

 source. Composite grain-size distributions for beaches based on coring will 

 probably produce conservative beach-fill model estimates because of the impor- 

 tance of storm-lag sediments concentrated in the nearshore sediment column. 



9. Significant patterns of sediment texture exist within the trap which 

 might be utilized during maintenance dredging to affect the performance of the 

 downcoast beach nourishment project. 



33 



