Storm, drift piles were richest in Ammophila bveviligulata propagules and 

 were widely distributed on Nauset Spit-Eastham in 1978. Large numbers of 

 Ammophila bveviligulata tillers appeared in these piles early in the growing 

 season. Deflation of open washovers made these debris piles appear as newly 

 developing dunes. In 1978 some of the Ammophila bveviligulata fragments that 

 regenerated in storm drift piles did not, however, survive the hot, dry summer 

 months. Rhizome development and aboveground plant growth were poorer than in 

 oceanic drift lines. 



Like bay drift lines, storm drift piles were less susceptible to storm 

 erosion than oceanic drift lines. Many of these piles developed around large 

 tangles of shrubs or remnants of destroyed cottages. Again spring tide drift 

 was deposited at lower elevations around these features and provided protec- 

 tion from erosion. While storm drift piles were poor in species diversity and 

 plant survival, they outlasted oceanic drift lines and helped to initiate dune 

 building. 



IV. BARRIER EVOLUTION 



1. Introduction. 



The evolution of Nauset Spit was determined from geologic core data, 

 historical charts and maps, sequential vertical photos, and detailed field 

 analysis of 15 areas on the spit. Stratigraphic profiles were constructed 

 from core data so that the third dimension of the barrier landform could be 

 analyzed to determine the role of principal processes in landward migration 

 and to establish a time frame for barrier rollover. Historic changes were 

 determined by an examination of old charts and maps dated as far back as the 

 early 1600's for Nauset Spit. These early charts provide a useful description 

 of the barrier, which can be used to corroborate and expand core information. 

 Data from early maps and charts, however, can only be used for qualitative 

 assessments, because early mapmaking was often subjective and inaccurate. 

 U.S. Coast and Geodetic Survey charts dating from 1851, made from controlled 

 field measurements, were used for quantitative analyses of recent trends. 

 Finally, detailed field analysis of areas with an established history yielded 

 information concerning rates and means of development of existing barrier 

 features. A complete picture of the evolution of Nauset Spit was assembled 

 from these four types of data. 



2. Geologic Trends. 



a. Methodo logy. A series of cores were taken along transects at Nauset 

 Spit-Eastham "wasliover site 1 (Fig. 13) and on North Beach (Fig. 90). The 

 relative elevation of each core was determined by transit and rod surveys for 

 cross-sectional analysis. Since permanent bench marks were, not available, 

 elevations were established in relation to an estimation of mean water level 

 (MWL) on the beach foreshore. 



Coring was conducted by the pile-driving technique, which can be accom- 

 plished by a few individuals in marsh or fine sandy substrates. At Nauset 

 Spit, however, the sediment is coarse sand (mean of 0.45 millimeter) which 

 made the coring very difficult and required additional manpower. 



149 



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