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The most widely known idea relates the depressions with deep, 

 subsurface solution of limestone (marl), with subsequent 

 slumping of surface sands (Bain 19 70 and LeGrand 1973). This 

 hypothesis does not go on to give any explanation for their 

 continued existance. Another hypothesis relates their continued 

 existance to illuviation and deposition of finely divided 

 organic detritus which forms an effective "plug" in subsurface 

 sand interstices. Another idea suggests the ponds occur over 

 ancient (Pleistocene) clay or muck deposits, laid down during 

 periods of higher ocean stands. 



A recent idea regarding formation suggests that the depressions 

 are ancient wind deflation pits (Personal Communication with 

 Dr. Victor Zullo, Department of Geology, University of North 

 Carolina at Wilmington, Wilmington, N. C. ). 



A published theory (Smith 1931) relates some natural ponds in 

 South Carolina to solvent action on subsurface pans formed by 

 illuviation in ancient sandy soils. As portions of the relict 

 pans have gone into solution, the surface sands have slowly 

 subsided. 



None of these ideas except, perhaps, the last explain both 

 origin and continued existance of the ponds over the entire 

 range of their variability. It may be that several factors are 

 responsible for their origin. 

 Physical Expressions : 



The ponds (or depressions) vary in extent from small fractions 

 of acres to many acres. Pretty Pond in eastern Brunswick County 



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