11a. Prose Description of Site: 



INTRODUCTION 



The Bull's Neck Swamp Natural Area occupies a large 

 peninsula along the southern margin of Albemarle Sound in 

 northeastern Washington County. The natural area encom- 

 passes about 6450 acres containing a mosaic of wetland 

 habitats over both organic and mineral soils. It is by 

 far the largest significant natural area remaining in the 

 county. 



Before describing the habitat diversity of the site, 

 an introduction to the area's geology and developmental 

 history will be outlined. According to Erlich (1980) 

 Albemarle Sound is an example of a drowned river valley. 

 About 8,000 to 10,000 years ago sea level was at least 

 46 feet lower than the present-day level. At this time 

 the Albemarle Sound basin was a vast alluvial floodplain 

 containing a meandering river channel and extensive 

 swamp forests. Since that time rising sea levels have 

 caused large scale flooding and enlargement of the Albe- 

 marle Sound to its present dimensions. 



Parts of the original river floodplain have filled 

 in with organic deposits caused by an accumulation of 

 decomposing swamp forest and marsh vegetation. The 

 present day lower portions of the Roanoke River basin 

 (see Conaby Creek Natural Area site report, pp. ) 

 and the Bull's Neck peninsula are examples of this 

 organic sedimentation. Close examination of aerial 

 photographs of Bull's Neck reveals a series of long, 

 arcuate sand ridges representing a relic fluvial ridge 

 and swale system which was probably formed during a low 

 sea level stand. Some of these ridges rise 5-8 feet 

 above modern sea level and have been cleared for cul- 

 tivation. Other ridges (within the natural area 

 boundary) are much lower, 1-4 feet msl; and are 

 periodically flooded by storm tides. The mantle of 

 organic deposits has apparently covered all but the 

 highest portions of these low-elevation ridges. This 

 topographic diversity has created areas of very deep 

 peat (former sloughs between the ridges) , areas of 

 very shallow peat (overlying low, now-buried portions 

 of the sand ridges) , and areas of higher ridges domi- 

 nated by loamy sands (not yet covered by the slowly 

 advancing peat mantle) . 



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