328 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT, 



Water and organic matter 1.807 per cent 



Potash .117 " " 



Soda .064 " " 



Lime .058 " " 



Magnesia ■. .042 " " 



Phosphoric acid .092 *' " 



Sulphuric acid .058 '" " 



Brown oxide of manganese .049 " " 



Peroxide of iron .224 " " 



Alumina .473 " " 



Soluble silica .879 " " 



Insoluble matter 95630 " " 



Total 99-493 '" " 



As compared with the three other northern Florida soils ana- 

 lyzed in the same report, this has the most potash, soda, and in- 

 soluble matter, and the least organic matter, lime, iron, alumina, and 

 soluble silica. Just why the potash should be so high in such a soil 

 is a puzzle ; unless possibly the woods had been burned over shortly 

 before the sample was taken. Additional analyses from the same 

 region would be very desirable. 



The soils of this region, as in other pine flatwoods regions, are 

 prevailingly acid. The soil survey of Bradford County gives the 

 amounts of lime (CaO) and limestone (CaC03) necessary to neu- 

 tralize the acidity of an acre of soil a foot thick for two of the prin- 

 cipal soil types. The following are the figures for the "Portsmouth 

 fine sand," in pounds : 



Lime Limestone 



Surface soil 3,850 7,700 



Hardpan stratum 6,300 12,600 



Subsoil 2,450 5,900 



Salamanders are common in the driest soils, but in much of the 

 area the ground-water seems to be too close to the surface for them. 



Topography and Hydrography — The topography is for the 

 most part flat, as in some of the regions previously described, but 

 the land rises gradually in leaving the coast, until at the inland edge 

 of the region it reaches elevations of about 150 feet at Jasper, 200 at 

 Welborn and Lake City, and 175 at Gainesville, It is noteworthy 

 that all along this edge the flatwoods are higher than the adjacent 

 hammock belt, which slopes westward toward the Gulf, Near the 

 edge are several deep sinks where the strata overlying the limestone 



