22 FLORIDA GEOLOGICAL SURVEY—FOURTH ANNUAL REPORT. 
coarse sand of the formation. The feldspar sands since their deposi¬ 
tion have been subjected to decay, thus forming the kaolinitic clay 
of the formation. 
SURFACE SANDS. 
Lying above these grits and sandy clays is found, very generally, 
a mantle of loose sand. This sand covering gives character to a 
large percentage of the soils of the upland, interior section of the 
State, giving rise to the light sandy soils and loams. A number of 
geologists, among whom are McGee*, Eldridgef and Veatcht, have 
regarded these sands as representing a distinct formation resting 
upon, and later than, the sandy clays. This hypothesis necessitates 
the assumption of a partial or complete resubmergence of the land 
subsequent to the deposition of the sandy clays, and hence if true is 
of much importance in its bearing on geological history and on soil 
formation. For this reason the hypothesis should be closely scruti¬ 
nized before being accepted. The writer believes that the hypothesis 
is untenable and that the sands are in fact residual in origin, being 
derived by the ordinary processes of decay and disintegration of the 
underlying materials. All the observations cited by these writers 
so far as they relate to the upland section of the interior of the State 
admit of explanation on the view of the residual origin of the sand, 
while many conditions not mentioned by them give further support 
amounting, it would seem, to a demonstration of their residual 
origin. 
McGee, it should be added, does not assume a complete resub¬ 
mergence of western Florida. The peninsula of Florida, he assumes, 
was entirely resubmerged following the deposition of the red clays, 
which he regarded as Lafayette. The sands at the depot at Monticello 
in Madison County, he refers to the Pleistocene, implying that the 
depression was sufficient to submerge that point (now 202 feet above 
sea according to the levels of the Atlantic Coast Line Railway), but 
was not sufficient to submerge the somewhat higher land one mile 
farther north. The reference by Eld ridge is specifically to the 
peninsula of Florida, which following McGee, he regards as having 
been resubmerged. Veatch in his paper relating to Georgia refers 
the sand overlying the Altamaha Grit to a separate formation of 
*McGee, W. J. The Lafayette Formation. U. S. Geol. Survey, 12th Ann. 
Rpt., pt. 1, 1891. 
fEldridge, George H. A Preliminary Sketch of the Phosphates of Flor¬ 
ida. Am. Inst. Min., Eng. Trans. Vol. XXI, 1893. 
tVeatch, Otto. Altamaha Formation of the Coastal Plain of Georgia. 
Science (n. s.) Vol. XXVII, p. 71-74, 1908. 
