11a. Prose Description of Site: 



The Conaby Creek-Roanoke River Natural Area is located in 

 the northwestern corner of the county. The 3240-acre tract lies 

 at the mouth of the Roanoke River at Albemarle Sound and includes 

 a portion of Conaby Creek, a tributary of the Roanoke which enters 

 the river at a point about one mile from its mouth. 



The natural area is situated entirely within the Roanoke 

 River floodplain at an elevation between sea level and four 

 feet. The entire tract is underlain by shallow to deep deposits 

 of organic muck which are interbedded with layers of inorganic 

 silts, sands, and clays deposited at various times by river flood- 

 waters. The organic muck soils and permanent high water table 

 are the primary factors which control the vegetation; a structur- 

 ally diverse but ecologically rather depauperate assemblage of 

 swamp forest and pocosin elements. 



The geological history of the area has recently been studied 

 by Erlich (1980) . A brief summary of the interesting geological 

 development of the area follows. 



The lower Roanoke River basin is an example of a drowned 

 river valley caused by flooding associated with rising sea level. 

 During the Early Holocene Period (7000 years before present) , the 

 Roanoke River in the natural area was characterized by typical 

 meandering stream depositional processes. At this time sea level 

 was approximately 46 feet lower than present day levels; there- 

 fore much of what is today covered by Albemarle Sound was at that 

 time an exposed broad, flat plain containing the meandering channel 

 of the Roanoke River. 



From 7000 years ago to the present the sea level has been 

 gradually rising. Albemarle Sound has been gradually expanding, 

 filling in the former river floodplain. As a consequence of the 

 rising sea level, organic deposits began accumulating in the 

 natural area, covering the inorganic muds and silts deposited 

 during earlier times. Today a vast body of peat-dominated swamp 

 forest wetlands have developed in the lower Roanoke River basin, 

 including the entire natural area section. 



The vegetation of the natural area is a complex mosaic of 

 various community types, of which all except one are tree-domi- 

 nated swamp forest wetland types. The palustrine/riverine wet- 

 lands have been influenced in the past by natural and man-induced 

 events. The influence of Roanoke River floodwaters carrying sus- 

 pended sediments such as silt and mud, storm and wind tides from 

 adjacent Albemarle Sound, and past logging operations are some 



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