2B. BASIN REGION. 53 



References.— Harper 1, McCalley 2 (5-6, 109-124, 128- 

 542), McCalley 3 (218-225), Mohr 8 (20, 90-93), Smith 

 4 (60-95, 105-109), Smith 6 (36-37, 106-108, 123), Smith 

 7 (212, 214-215, 399-404, 445-448), Tuomey 1 (81-93). 



Geology and soils. — The sandstones of the plateau just 

 described dip southwestward, and in the basin region are 

 covered deeply in most places with newer strata, still be- 

 longing to the Coal Measures. Although, some pretty 

 thick beds of sandstone are found in the basin, the rocks 

 are as a rule shaly ; and there are also a few thin beds of 

 limestone and of iron ore, according to McCalley, as well 

 as many coal seams of varying thickness. In a few 

 places near the southeastern edge of the Warrior basin 

 and in the Cahaba and Coosa fields the strata are con- 

 siderably crumpled and faulted, but elsewhere they are 

 nearly horizontal. 



No analyses of soils in the basin region seem to be 

 available, but they are more clayey as a rule than those 

 of the plateau, though perhaps not any more fertile, on 

 the uplands at least. Agricultural operations are chiefly 

 confined to bottom-lands. 



Topography and hydrography. — Erosion has pro- 

 gressed much farther here than in the plateau region, 

 partly because the rocks are softer, and perhaps also for 

 other reasons, and the topography is what would be 

 called mature, or even old in some parts. There is little 

 level land on the uplands, and many of the creeks flow 

 through rather wide flat-bottomed valleys bordered by 

 bluffs. The railroads and settlements are mostly in the 

 valleys, instead of on the uplands as they are in the 

 plateau region. There are few steep bare cliffs in the 

 basin region, the bluffs formed by erosion being mostly 

 well rounded in outline, and densely wooded. Waterfalls 

 and natural bridges are scarce. The smallest streams 

 usually head in rich ravines which are dry a large part 

 of the time. There are no big springs or subterranean 

 streams. The smaller creeks dry up in summer, and the 

 larger ones and the rivers are usually somewhat turbid, 

 and have considerable seasonal fluctuation. A few have 

 their sources in limestone valleys belonging to the next 



