25. Physiographic characterization of natural area: 



Pyroclimax marsh grass community on mixed organic-alluvial 

 deposit below mouth of Corapeake Swamp, on the western boundary of 

 the Great Dismal Swamp, in the Embayed Section of the Coastal Plain 

 Province of the Atlantic Plain. 



Geological formation: Holocene organics and alluvium over 

 the Sand Bridge and Norfolk Formations. 



Geological formation age: 



Mixed organics and alluvium: Holocene (11,000 yrs. ago to present) 



Sand Bridge and Norfolk 



Formations : 35,000 to 115,000 yrs ago. 



References cited: Oaks, R. Q., Jr. and D. G. Whitehead. 1979. 

 Geologic setting and origin of the Dismal Swamp, southeastern 

 Virginia and northeastern North Carolina. In: P. W. Kirk, Jr., 

 ed. The Great Dismal Swamp. Charlottesville: Univ. of Virginia 

 Press. 427 p. 



Oaks, R. Q., Jr. and N. K. Coch. 1963. Pleistocene sea levels, 

 southeastern Virginia. Science 140: 979-983. 



Daniels, R. B., E. E. Gamble and W. H. Wheeler. 1978. Age of 

 soil landscapes in the Coastal Plain of North Carolina. Soil 

 Sci. Soc. Am. J. 42:98-105. 



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