The extensive preservation of backbarrier sediments, dated between 7,000 

 and 8,000 year B.P., on the inner shelf of southern Long Island suggests that 

 the barriers have not retreated by continuous shoreface erosion alone but have 

 also undergone discontinuous retreat by in-place "drowning" of barriers and 

 stepwise retreat of the surf zone landward. This would have locally prevented 

 the backbarrier sediments from being reworked and thus would lead to their 

 preservation on the inner shelf. (Authors). 



284 RAMPING, M. R. , and SANDERS, J. E. 1981a. "Episodic Growth of Holocene 

 Tidal Marshes in the Northeastern United States: A Possible Indicator of 

 Eustatic Sea-Level Fluctuations," Geology . Vol 9, pp 63-67. 



Development of coastal marshes during the Holocene submergence of the 

 northeastern United States seems to have been episodic. Radiocarbon dating of 

 the modern marshes indicates that they were generally established within the 

 past 3,000 year. Initiation of marsh growth was probably related to the 

 marked slowing in the submergence rate that took place in the area about 3,000 

 to 4,000 year ago. On the basis of the few available dates of marsh peats 

 from the inner continental shelf, we suggest that previous episodes of marsh 

 growth took place at about 4,700, 5,600, 6,600, 7,700, 8,200, and 

 8,600 radiocarbon year ago. These times of marsh growth seem to coincide with 

 proposed times of negative sea-level oscillations, cool climate, and glacial 

 advances. If these oscillations of sea-level are climatically controlled, 

 then the data suggest an approximately 1,000-year cycle of climatic change. 

 (Authors) . 



285 RAMPING, M. R. and SANDERS, J. E. 1981b. "Evolution of the Barrier 

 Islands of Southern Long Island, New York," Sedimentolopy . Vol 28, pp 37-47. 



Three lines of evidence based on data from more than 400 boreholes and 

 vibrocores have been used to reconstruct the evolution of the barrier islands 

 during the Holocene transgression in southern Long Island, New York: (1) the 

 Holocene transgressive stratigraphic sequence behind the present barrier, 

 (2) the stratigraphic patterns of the inner shelf, and (3) the morphology of 

 the now-buried late Pleistocene coastal features. 



The extensive preservation of backbarrier sediments, radiocarbon dated 

 between 7,000 and 8,000 year B.P., on the inner shell of southern Long Island 

 suggests that the barriers have not retreated by continuous shoreface erosion 

 alone, but have also undergone discontinuous retreat by in-place 'drowning' of 

 barriers and stepwise retreat of the surf zone. Such stepwise retreat of the 

 surf zone has prevented the backbarrier sediments from being reworked. 



Based on the presence of submerged barrier sand bodies in seismic 

 records, it is inferred that about 9,000 years ago, when the sea stood about 

 24 m below the present sea-level, a chain of barriers developed on the present 

 shelf about 7 km offshore of the present barriers. With continued sea-level 

 rise, the -24 m barrier built upward until the sea reached about -15 m MSL, 

 just prior to 7,000 year B.P. The barriers were then submerged by the rapidly 

 rising sea, and the surf zone shifted rapidly landward to a position about 

 2 km from the present shoreline. The surf zone overstepped to the landward 



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