ECOLOGICAL INVENTORY SUMMARY 



Russell Kologiski's The Phytosociology of the Green Swamp and the National 

 Park Service Green Swamp report elaborate many of the ecological features within 

 the swamp. Much of the following general summary is taken from these sources, 

 and they may be referred to for further information. 

 Abiotic Features 



Geology 



The Green Swamp is located on the Penholoway Terrace, one of a series of 

 marine terraces formed as the Atlantic Ocean retreated across the Coastal Plain. 

 It may also be a shoal system of deltic origin formed during the early Medial 

 Pleistocene. NCNC's property is located in the southeast corner of the Green 

 Swamp, approximately fifty to seventy feet in elevation. Detailed geological 

 surveys of the swamp and NCNC's land have not been made. Pleistocene surficial 

 deposits of sands and mixed clays twenty-five to thirty feet thick underlie the 

 entire swamp. Beneath these deposits lies the Late Cretaceous Peedee Formation 

 of clays with interbeds of calcareous sands. The Duplin and Waccamaw Marls of 

 the Miocene age possibly lie between these two stratigraphic units. 



The southern edge of the property borders a scarp, an ancient shoreline. 

 Beneath surficial deposits here lies the Eocene Castle Hayne Limestone Formation. 

 A series of sinks, including two large and several smaller ones in the 

 Myers-Clemmons tract, have probably resulted from underground solution within 

 this formation. Carolina Bays, unusual elliptical geomorphic features of the 

 Atlantic Coastal Plain, are frequent along this southern edge. Evidence of 

 bays within the pocosin is indicated from aerial photographs. 



Topography 



The topography of the Green Swamp is a function of beach formations 

 developed during the last inundation, erosion since then, the build-up of peat, 

 and the formaiion of Carolina Bays. The Conservancy's land lies on a broad, 

 interstream northwest-southeast trending ridge at the terminous of the Waccamaw 

 River and Cape Fear River divide. The formation of peat deposits began 

 approximately 10,000 years ago in low, wet areas. Acting like a growing, 

 spreading sponge, it developed laterally, overtopping many topographic highs. 

 To the scanning eye the terrain appears flat, although the center is domed. 

 Higher ridges and bay rims within the swamp outcrop as "islands." Map 1 

 displays these features. The property lies within the Supply, Bolivia, Honey 

 Island, and Lewis Swamp, N.C. 1:24,000 topographic quad maps. v 



lai 



