76 MINERAL RESOURCES OF ALABAMA. 



they grade into each other in such a way that the actual num- 

 ber is far greater. 



T. Sandy Loams, in part slightly calcareous. These are 

 derived from the sandstones and siliceous shales of the Coal 

 Measures, the Weisner Quartzite, and the Talladega Slates ; 

 from the cherty or more siliceous parts of the Knox Dolomite, 

 and of the Lower Carboniferous Limestones ; and from some 

 of the Montevallo Shales. Naturally these soils are less fer- 

 tile than the others, but on the other hand, they lie well, are 

 easily cultivated and responsive to fertilizers. Perhaps 10,- 

 ooo square miles of the Mineral region have soils of this kind. 



2. Calcareous Sandy Loams. In these the proportion of 

 clay and by consequence, of lime, is greater than in the pre- 

 ceding class; the soils are inherently more fertile, and quite 

 as easy of cultivation and as responsive, and hence form the 

 most desirable farming lands of this section. They cover 

 about 4,000 square miles of territory and are the residual soils 

 from the slightly siliceous limestones of the Tuscumbia d' vi- 

 sion of the Lower Carboniferous, the Fort Payne Chert, the 

 lower beds of the Knox Dolomite, and the more calcareous 

 of the Montevallo Shales, and the rocks of the Red Mountain 

 group. The fine red lands of the Tennessee Valley, those of 

 parts of the great Coosa Valley, and belts in the other anti- 

 clinal valleys are of this character. 



3. Highly caleareous clayey soils. These occupy some 

 2,500 square miles of area,, and are derived from the purer 

 limestones of the Lower Carboniferous, and of the Trenton, 

 and from the calcareous shales of the Flatwoods. The parent 

 rocks appear along steep hillsides or else in flat, badly drained 

 valleys, and the soils are in consequence generally too rocky 

 or too wet for cultivation; and while essentially fertile, they 

 are of comparative little value as farming lands. 



The Coastal Plain. 



The upland soils of the Coastal Plain, as has been intimat- 

 ed, are in the main based on the materials of a single forma- 

 tion, the Lafayette, which as a mantle of sandy loam and peb- 

 bles has been spread over the entire district with an average 

 thickness of 25 feet. When unmodified by admixtures with 



