I.ltiv AKY 

 N- v> YORK 

 (JOIAINICAL 



TORREYA -«"«" 



Vol. 22 No. 4 



July- August, 1922 



SOME PINE-BARREN BOGS IN CENTRAL ALABAMA 



Roland M. Harper 



From Delaware to northern Virginia and from central North 

 Carolina to Tennessee, there is at the inner border of the coastal 

 plain a hilly belt several miles wide, characterized by large 

 amounts of sand, gravel, or mottled clay of fresh-water origin, 

 all deficient in fossils and in line, and making rather poor soils, 

 with a considerable development of pine forests. The clay seems 

 to predominate in Maryland and the sand in the Carolinas and 

 Georgia, while the gravel is most abundant in Alabama and 

 Mississippi.* 



East of the Potomac River and west of the Flint River the 

 pine-clad hills near the fall-line are separated from the pine- 

 barrens nearer the coast by a fertile strip underlaid by calcareous 

 strata mostly of late Cretaceous age, which many typical pine- 

 barren species have apparently been unable to cross. f It is 



* Geologists are not yet completely in agreement as to the age of these 

 deposits. Those in Maryland are referred without question to the Potomac 

 group (Lower Cretaceous). The sand-hills of North Carolina are regarded 

 by L. W. Stephenson (N. C. Geol. Surv. Vol. 3: 261. 1913) as belonging to 

 the Lafayette (Pliocene), while about a year before the same author (Geol. 

 Surv. Ga. Bull. 26: 450-454. 1912) was inclined to treat the same sort of 

 thing in Georgia as residual from the Cretaceous formations. The corres- 

 ponding region in Alabama is based on the Tuscaloosa formation (E. A. 

 Smith, Geol. of Coastal Plain of Ala. 307-349. 1895), which is now regarded 

 by members of the U. S. Geological Survey as being Lower Cretaceous east 

 of the Coosa River and Upper Cretaceous west of there. 



t For quantitative lists of trees in different parts of the fall-line hills, with 

 references to earlier publications, or other additional information, see the 

 following:— 



Maryland: Jour. Wash. Acad. Sci. 8: 584. Nov. 1918. (Map in Jour. 

 Forestry 17: 548. 1919.) 



North Carolina: Jour. Elisha Mitchell Sci. Soc. 33: 112. 1917. 



Sotith Carolina: Bull. Torrey Bot. Club 37: 413. 1910; 38: 225. 191 1. 

 (Map in Jour. Elisha Mitchell Sci. Soc. 35: pi. 2Q. 1920.) 



(CofiHmied al bottom of following pise-) 



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