a 
3 
E 
E.. A. Smith—Geology of Florida. 299 
stone between the St. Johns River and the elevated table lands 
westward. 
The following notes present proofs more or less conclusive 
made: 
_ of the statement above 
1. West Florida. 
The occurrence of Vicksburg limestone in Jackson Count: 
has already been noticed, and specimens of Orbitoides Mantelli, 
Pecten Poulsoni, and other characteristic fossils were collected 
in situ at several localities, e. g., a few miles southeast of 
Campbellton, at the Big Spring east of Marianna, etc., while the 
use of blocks of this stone in the construction of chimneys, 
through the eastern and northern portion of the county, attest 
Its occurrence everywhere in those parts. In the region 
referred to, the limestone lies very near the surface, often out- 
cropping over considerable areas, and to this circumstance is 
probably due the exceptional fertility of much of the soil of 
Jackson County. 
Holmes Valley on the creek of same name in Washington 
County, another widely-known fertile tract of land, presents 
the same geological features as the portion of Jackson County 
Just mentioned, 
“boiling” springs, sink-holes, ponds and lakes, taken in con- 
hection with the distribution of the Orbitoides limestone in the 
adjacent counties of Alabama, make it almost certain that this 
rock underlies most of West Florida, down at least to the near 
Vicinity of the Gulf coast. 
2. Middle and South Florida, — 
In these portions of the State my observations have covered 
a larger extent of country and are correspondingly more con- 
elusive as to their geological structure. ;. 
ear the village of Chattahoochee, the bluff of the Appa- 
lachicola River is formed in part by the Vicksburg limestone, 
Which has here a tolerably thick covering of Stratified Drift, 
ronsisting of reddish and yellow sands with some small peb- 
bles. The greater part of Gadsden County, as far east at least 
at Mount Pleasant, I feel very well convinced that the Vicks- 
burg limestone makes its appearance along the river as far 
South as Rock Bluff, 
