WATER SOILS. 959 



and pebbles, transported from elsewhere, and the soils are in great measure made 

 from these materials, modified, however, locally by admixtures with the disintegra- 

 tion and decomposition products of the underlying older rocks." 



The soils of the mineral district are derived mainly from sandstones, shales, and 

 limestones, although in each case there are admixtures of material from other sources 

 which give rise to a great variety in the resulting soils. There are three prominent 

 types of these soils, (1) sandy loams, in part slightly calcareous; (2) calcareous sandy 

 loams, and (3) highly calcareous clayey loams. The upland soils of the Coastal 

 Plain are in the main based on materials derived from the Lafayette formation, 

 which as a mantle of sandy loam and pebbles has been spread over the entire dis- 

 trict to an average depth of 25 ft. When unmodified by admixtures these soils are 

 highly siliceous loams, usually colored a deep red by iron oxid. " They are well 

 drained, well situated, and among the most desirable of our farming lands, because 

 of these qualities and of the ease of working and capability of improvement. At the 

 other extreme they are very sandy and comparatively infertile in the natural state, 

 yet some of the most valuable truck farms of southern Alabama have soils of this 

 class. . . . 



"Where the limestones of the Selma chalk and of the St. Stephens underlie and 

 constitute the country rocks, the soils show marked departure from the prevailing 

 type of Coastal Plain sandy loams. From these areas the Lafayette sands have often 

 been in great part swept away by erosion, and the soils are in a measure residual, 

 being the insoluble clayey residues from the decay and disintegration of the lime- 

 stones. 



"Like all clayey soils derived from limestones, they are of exceptional fertility, 

 and make the very best farming lands of the State. Such are the soils of the great 

 Black Belt or Canebrake Belt of central Alabama, and those of the lime hills and hill 

 prairies of the southern part of the State. Remnants of the Lafayette mantle occur 

 at intervals through all these regions, and admixtures of the red loams of this mantle 

 with the native marly soils give rise to many varieties, such as the Red Post Oak 

 soils, the Piney Woods Prairie soils, etc. 



"Another departure from the prevailing Coastal Plain sandy loams is caused by 

 the great clay formation of the lower tertiary, which gives origin to the Post Oak 

 Flatwoods of Sumter and Marengo counties. East of the Alabama River in Wilcox 

 and Butler counties, these clays bold much lime and form regular 'prairie' soils, 

 characteristically developed along Prairie Creek in Wilcox. 



"Besides the above, there are small areas of marly soils in the tertiary, due to 

 the shell beds which occur at intervals in the lower or lignitic division of this 

 formation. . . . 



"In the lower counties of the State the materials of the Lafayette are in general 

 more sandy than is the case farther north, and we find in this section also another 

 surface mantle, viz., the Grand Gulf, underlying the Lafayette, and like it consisting 

 mainly of sands with some beds of laminated clay intercalated. . . . 



"Along all the larger streams of the Coastal Plain region we find developed nor- 

 mally three well-defined terraces. The first terrace or bottom is subject to overflow 

 and its soils are the sands and other materials periodically deposited by the stream, 

 and are the most recent perhaps of the formations. A few feet above the high-water 

 mark and consequently not subject to overflow except in the depressions caused by 

 erosion, are the second bottoms, with very characteristic soils, yellowish silty loams 

 increasing in sandiness from above downward. The second bottoms are on an aver- 

 age perhaps a mile in width, and are always choice farming lands. Upon this terrace 

 are many of the great plantations of ante-bellum days. 



"About KK) ft. above the second bottom we find a third terrace averaging some 

 3 miles in width, the soils of which are of the usual Lafayette type, red sandy loam 

 underlain by pebbles," 



