THE SOILS OF FLORIDA. 
25 
Next above the red loams are the loose surface sands already 
referred to. From these sands the clay has been largely removed by 
the surface water. These sands are usually ochre yellow in color, 
the iron having become hydrated, while those most affected by sur 
face waters may have largely lost their stain, becoming light gray 
in color. The clay which originally acted as a cementing material 
has also been largely removed by the percolating waters, having 
either been carried to a lower depth or washed away entirely. Other 
cementing substances, if originally present, have been removed in 
solution, the resulting sands being loose and friable. The line of 
demarcation between this loose sand and the underlying loam as 
already explained is often an irregular line and practically always 
a well marked line. 
The gray and yellow loose sands have been referred to above. It 
may be noted that invariably in localities where the drainage is 
sufficient to remove all or nearly all the organic matter, the top 
sands are gray or light colored, but that at a depth of from a few 
inches to a few feet the gray sands give place to ochre yellow sands, 
and various writers have sought to distinguish between the gray 
surface and the ochre yellow sands beneath. That no such distinc 
tion exists has been well pointed out by Mr. Samuel Sanford in the 
Second Annual Eeport of this Survey, 1909. The difference in color 
is due to different chemical action. Near the surface where the 
sands become thoroughly drained and aerated they bleach light or 
gray; deeper within the earth where the sands remain more or less 
moist the sands retain the ochre yellow color. Even originally light 
colored sands, will develop the yellow color when acted upon by 
surface waters carrying more or less organic acids in solution. That 
this is the case may be seen by examining a cross section of any one 
of the quiescent sand dunes covered with more or less vegetation. 
In the dunes along the coast the surface sands to a depth of one to 
three feet are light gray, but below the gray sands and separated 
from them by a well marked line, the sands become ochre yellow, thus 
showing the effects of staining of the sands by surface waters. When 
originally accumulated the dune sands were doubtless light colored 
and uniform throughout. 
AGE OF THE GRITS, SANDS AND SANDY CLAYS. 
Aside from their relation to soil formation the clayey sand de¬ 
posits present some interesting geological problems. The fact that 
the material is coarse, indicates that it was moved to its present 
location by strong currents; the cross bedding and irregularity of 
