eckbl.] WHITE PHOSPHATES OF DECATUR COUNTY, TENN. 425 
Creek about 10 miles south of Decaturville. Of these, the second 
area only was visited, the others not having been developed so exten- 
sively. So far as can be estimated at present, the three areas together 
contain some 300 to 400 acres of land on which the phosphate exists 
in workable thickness and quality. 
In the Beech River area the phosphate is found on the low divides 
lying between the various tributaries of Beech River. Of the streams 
entering from the north, only Bear Creek shows phosphate. Along 
the tributaries coming from the south the phosphate deposits are more 
numerous, workable quantities being found on the divides between 
these streams as far east as Lost Creek. As yet no idiosphate has 
been found between Lost Creek and the Tennessee River. 
Occasionally the phosphate shows at the surface, but commonly it is 
concealed by other materials. A typical pit in this area would show 
a section, from the ground surface down, about as follows: 
Typical section in the phosphate field of Decatur County, Tenn. 
Feet. 
Chert fragments, mingled with soil or clay 2-5 
Phosphate fragments, scattered through clay . __ 1-3 
Massive phosphate . _ _ 3-8 
Unaltered limestone (Silurian). 
The overburden, as shown in the pits visited, rarely exceeded 5 or 
6 feet. It should be remembered, however, that most of these pits 
are located on the lower levels of the divides, and that the thickness 
of the overburden may be expected to increase as the workings get 
farther into the hill; for Dr. Hayes has shown that deposits of white 
phosphate, though in no sense stratified, occupy practically horizontal 
positions. 
At the time of the writer's visit, in 1901, the greatest thickness of 
phosphate shovfoi in any of the prospecting pits was 18 feet, and the 
writer then estimated the average thickness in the pits at 5 feet. 
Active exploitation of the deposits has developed the fact that these 
statements were too conservative rather than too nattering to the new 
district. Much greater thicknesses are now shown in the workings 
near Beech River, and it is said that one mine shows a thickness of 
over 30 feet of workable phosphate. 
The rock from this area, as mined, will average 75 to 77 per cent 
bone phosphate. A series of analyses by Mr. L. P. Brown, of Nash- 
ville, Tenn., shows that it varies from 70 to 85 per cent bone phos- 
phate, while its content of iron oxide and alumina together varies from 
less than 1 to about 3 per cent. . 
Aside from the areas in southern Decatur County, above described, 
it is probable that workable white phosphate deposits will be found 
farther to the north. One such area is now being carefully examined, 
and may prove to be worth exploitation. The black bedded phosphates 
(Devonian) have also been reported from various points in northern 
Decatur County, but at present no trustworthy data regarding the 
value or distribution of these deposits are available. 
