266 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT. 



1 1 . TALLAHASSEE RED HILLS. 

 (FIGURES 32, 34, 69-73) 



References. Harper i (282-283), Matson & Clapp (99, 144), Matson &■ 

 Sanford (149, 350-353), Sel'.ards i (47-49, 53-58), SeHards & Gunter 3 (133- 

 136, 138), Smith 2, Thompson, Torrey, and U. S. soil survey of Leon 

 County (by Wilder, Drake, Jones and Geib), 1906. Illustrated in 3d Ann. 

 Rep., pi. 6, 7.1, 8.1 (all lake scenes), and in Pop. Sci. Monthly 85:349- I9i4- 



This region bears much the same relation to the adjoining ham- 

 mock belt that the Marianna red lands do to the West Florida cy- 

 press pond region already described. Each is similar geologically to 

 the country bordering it on the west, north and east, but is cnaracter- 

 ized by richer, redder soils, more hilly topography, a scarcity of 

 long-leaf pine, and other characters correlated with the soil and to- 

 pography. Furthermore, they do not differ much in area, and each 

 is almost confined to a single county, and barely crosses the north- 

 ern boundary of the State. 



The Tallahassee red hills are estimated to cover 340 square 

 miles, all in Leon County or possibly extending a little beyond its 

 borders on the north and east. There is nothing exactly like it in 

 any other part of Florida, or the world, except that there are limited 

 areas very similar to parts of it in the Middle Florida hammock 

 belt, in Jefferson and Madison Counties. Many persons have com- 

 pared this hill country to the red hills of South Georgia, but the two 

 regions are entirely disconnected, and the resemblance is only super- 

 ficial, for there are fundamental differences in geology, soil, topog- 

 raphy and vegetation. 



Geology and Soils — Rock outcrops are scarce and poor in fos- 

 sils, but from what is known of the surrounding country, and the 

 records of a few wells, the underlying rocks have been mapped as 

 Upper Oligocene. Most of the material exposed in railroad cuts 

 and other excavations is a reddish brown sandy clay. Several feet 

 below the surface it is sometimes purer, and mottled somewhat as in 

 the pine regions of West and East Florida. Nodules or fragments 

 of a gritty yellowish rock containing over 15% of phosphorus 

 pentoxide (equivalent to over 30% of tri-calcium phosphate, or 

 nearly half as much as in some of the phosphate rock that is mined 

 in peninsular Florida) are common in many places, either close to 

 the surface or a few feet down; while in many other places fer- 

 ruginous concretions an inch or less in diameter are scattered over 

 the surface, as in the "pimply lands" of South Georgia and West 



