130 FLORIDA geological" SURVEY I3TH ANNUAL REPORT 



. 8. PENINSULAR FLATWOODS, WESTERN DIVISION 



(Figs. 23-25. Soil analyses 27-36, H, J, X.) 



Besides the flatwoods already described, there is a much larger 

 area, covering the greater part of the peninsula south of our limits, 

 which may be divided into several regions when it is more thor- 

 oughly explored. In the latitudes under consideration it is divided 

 by the lake region into two parts, which may conveniently be 

 treated separately. The western portion, which will be discussed 

 first, has an area of about 1,700 square miles. 



Geology. The strata beneath the surface sands range from Up- 

 per Oligocene to Pliocene, and are more or less calcareous and phos- 

 phatic ; and although natural exposures are comparatively rare, they 

 influence the soil perceptibly in many places. The Pliocene is rep- 

 resented by the Bone Valley formation, which includes the pebble 

 phosphate deposits, and is chiefly confined to Polk County. The 

 mining of this phosphate is perhaps the most important industry 

 in the region. Flowing artesian wells can be had almost anywhere 

 • near the coast. There are a few mineral springs, such as Espiritu 

 Santo near Safety Harbor and Kissingen near Bartow. 



Topography. The surface is comparatively level, as implied by 

 the name "flatwoods," but fairly "well drained." It has the ap- 

 pearance of having been uplifted a little in comparatively recent 

 times, for near the coast and rivers one can in many places ascend 

 25 feet in less than a mile, and numerous creeks and branches have 

 cut narrow valleys below the general level. San Antonio, at the 

 upper edge of the region in Pasco County, is said to be 160 feet 

 above sea-level. Shallow depressions a few acres in extent, which 

 hold a foot or two of water in wet seasons, are very common, es- 

 pecially northward, but there are very few lakes, the ponds being 

 in most cases well filled with cypress and other trees. There are 

 more streams in proportion to area than in the other regions, but 

 none of them are considered navigable. 



Soils. The soil is nearly everywhere sand, of various color? 

 from white to brown, but the underlying rock or marl seems to be 

 usually within a few feet of the surface, making calcareous soils 

 in many low places. The soil surveys of Pinellas and Hillsborough 

 Counties (1914 and 1918) cover the greater part of the area. In 

 those publications the soils are referred to the "Leon," "Ports- 



