BUREAU OF AMERICAN ETHNOLOGY 



[Bull. 137 



7. Central Lowland., d, Till Plains. 



7d, Young till plains; morai- 

 nic topography rare; no 

 lakes. 



e, Dissected Till Plains. _ 7e, Submaturely to maturely 



dissected till plains. 



f, Osage Plains 7f, Old scarped plains bevel- 



ing faintly inclined 

 strata; main streams 

 intrenched. 



8. Great Plains prov- 



ince. 



9. Ozark Plateaus 



(This barely appears upon 

 the map.) 



a, Springfield-Salem pla- 



teaus. 



b, Boston "Mountains". _ 



9a, Submature to mature pla- 

 teaus. 

 9b, Submature to mature pla- 

 teau of strong relief. 



10. Ouachita prov- a, Arkansas Valley 10a, Gently folded strong and 



ince. weak strata; peneplain 



with residual ridges. 



b, Ouachita Mountains 10b, Second-cycle mountains 



of folded strong and 

 weak strata. 



Degrees of relief are herein spoken of as low, moderate, strong, and high. As 

 used here high relief is measured in thousands of feet; moderate relief in 

 hundreds of feet. Strong relief may be anything approaching 1,000 feet with 

 a wide latitude on both sides. 



Major divisions are separated by the heaviest lines. Provinces are distinguished 

 by numbers; sections by letters. Broken lines indicate boundaries much 

 generalized or poorly known. 



More than three-fourths of the primary area is included in the 

 Coastal Plain. Midway between the Atlantic and the Mississippi 

 River this plain is dented by the Blue Ridge and the Appalachian 

 Plateau with the narrow Appalachian Valley between them, and 

 flanked by lower land masses, the Piedmont Plateau on the east of the 

 Blue Ridge and the Interior Low Plateaus on the west side of the Ap- 

 palachian Plateau. West of the Mississippi the Coastal Plain is 

 dented slightly by the Ozark and Ouachita Plateaus, themselves sepa- 

 rated by the narrow Arkansas Valley peneplain. 



Geographers have subdivided each of these physical areas into 

 two or more portions on account of minor characteristic differences, 

 but most of these are without serious ethnological significance. The 

 subdivisions of the great Coastal Plain do, however, have some 

 importance for us. They include: (1) The Embayed section, "a 

 submaturely dissected and partly submerged, terraced coastal plain" ; 

 (2) the Sea Island section, a "young to mature terraced coastal plain 

 with submerged border"; (3) the Floridian section, a "young marine 

 plain, with sand hills, swamps, sinks, and lakes"; (4) the East Gulf 

 Coastal Plain, a "young to mature belted coastal plain"; (5) the 



