classic descriptive models of barrier sedimentation have been developed 

 with data from the Atlantic and Gulf coasts of the United States. These 

 models are dominated by low to moderate rates of relative sea- level (RSL) rise 

 and wave energy. Barriers respond by landward recycling of sediment through 

 the mechanism of shoreface retreat. Sedimentation processes on the central 

 coast of New South Wales (N.S.W.), Australia, consist of rapid RSL rise in 

 early Holocene times followed by a stillstand since 6500 B.P. Wave energy is 

 relatively high year-round and sand sources for barrier formation are only 

 found on the inner shelf. Barrier sedimentation on the central coast of 

 N.S.W. exhibits a thick, composite sequence composed of a basal marine 

 transgressive sand overlain by regressive beach and dune facies. 



The Louisiana coast surrounding the Mississippi delta is underlain by 

 compacting deltaic muds which generate very rapid rates of RSL rise. The 

 Louisiana coast experiences low wave energy punctuated by high- energy tropical 

 and extra- tropical storm events. Barrier sediments accumulate from the 

 erosion of deltaic headlands and undergo a transformation from subaerial 

 barrier island systems to subaqueous shoals located on the inner shelf. 

 Drumlins experience coastal erosion on the Eastern Shore of Nova Scotia and 

 provide a sediment source for compartmented estuary mouth barriers. An 

 ongoing, moderate rise of RSL results from the passage of a glacial forebulge. 

 Wave energy is intermediate between Louisiana and N.S.W. and displays a 

 seasonal pattern dominated by frequent winter storms. Coastal barrier 

 sedimentation is episodic, consisting of a period of beach ridge progradation 

 followed by barrier destruction and re-establishment further landward. 



The three contrasting sedimentary sequences found in examples from 

 Louisiana, N.S.W. and Nova Scotia indicate that presently available sedimenta- 

 tion models from locations such as the middle Atlantic or Texas coasts of the 

 United States may only represent well -documented regional case studies. A 

 true generalized coastal sedimentation model is required which can identify 

 the parameters controlling vertical and horizontal translation of the deposi- 

 tional surface and provide relationships between these parameters which 

 quantitatively predict the genesis, distribution and geometry of coastal 

 sedimentary facies. (Authors). 



030 BRAATZ, B. V., and AUBREY, D. G. 1987. "Recent Relative Sea-Level 

 Change in Eastern North America," Nummedal, D., Pilkey, 0. H. , and Howard, 

 J. D., eds . , Sea-Level Fluctuations and Coastal Evolution . Special Publication 

 No. 41, Society of Economic Paleontologists and Mineralogists, Tulsa, OK, 

 pp 71-86. 



Eigenanalysis of tide-gage records between 1920 and 1983 in eastern 

 North America reveals highly variable spatial and temporal patterns of 

 relative sea- level change. Auxiliary data from numerical modeling suggest 

 that much of the long wavelength (thousands of kilometers) spatial patterns of 

 sea-level change are due to postglacial isostatic adjustment of the land 

 surface. Filtering the isostatic component from the rates of relative sea- 

 level movement yields residual rates that fluctuate about a coastal mean of 

 1.0-1.5 mm/year during this 64 year time interval. This mean rate is within 

 the range of previous estimates of mean rate of eustatic rise in sea- level 

 during the past century. Some residual fluctuations (wavelengths of tens to 

 hundreds of kilometers) correlate with tilts of the land surface revealed by 

 geodetic leveling transects, and appear to be related to regional geology 



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