patens had become established, the 

 high marsh peat kept accreting in 

 response to rising sea level. Thus, a 

 thick section of S^. pa tens peat lay 

 over a thin layer of S. alterni flora 

 peat which was underlain by a mud flat 

 deposit. It was not until A.C. 

 Redfield (1572) carried out his 

 extensive studies of the Barnstable 

 Marsh in Cape Cod that a well- 

 documented and comprehensive picture 

 of marsh development on the northeast 

 coast emerged. 



Data collected from the Barns- 

 table marsh confirmed the model 

 proposed earlier by Redfield (1965; 

 Redfield and Rubin 1962) in which the 

 sequence of events described by Shaler 

 was placed in the context of a rising 

 sea level. It was clearly shown that 

 views of Mudge and 

 at least in part, 

 had focused on the 

 of the marsh while 

 had been looking primarily 

 seaward side. With a rising 

 sea level and a sufficient sediment 

 supply, Redfield (1972) found that 



the different 

 Shaler arose. 



because 

 upland 

 Shaler 

 at the 



Mudge 

 side 



the intertidal S. alterniflora peat 

 extended progressively out from shore 

 and at an upward slope over an 

 aggrading sand and mud deposit. The 

 high marsh peat then formed over the 

 intertidal peat as a wedge which 

 thinned as it expanded toward the 

 upland and toward the seaward edge of 

 the marsh (Figure 5). Cores taken in 

 areas where the marsh had overgrown 

 the upland in response to rising sea 

 level would contain only 

 deposit of high marsh 

 reported by Mudge, while 

 the outer portions of the 

 appear as described 



his care and 



a uniform 



peat, as 



cores from 



marsh would 



by Schaler. 



Despite all his care and efforts, the 

 many cross sections examined by 

 Johnson (1925), and which confirmed 

 only Mudge 's views, happened to come 

 from areas in the marshes that had 

 formed over old upland sites or from 

 marshes in which erosion had removed 

 areas of recent marsh accretion. 



The marshes are growing out and 

 over the sand and mud flats as well as 

 up and around the rocks. 



UPLAND 



HIGH MARSH PEAT , ■ — '" pEf''^ '^\k 



te" 



...•"•I 





HWe 



■>T. SAND 



Figure 5. Redfield 's 

 sediment on a sand flat 

 level (Redfield 1972). 

 development. 



model for salt-marsh development over accumulating 

 and over the upland under the influence of rising sea 

 HW refers to mean high water at various times during 



8 



