WATER SUPPLY OP PASTERN AND SOUTHERN FLORIDA. 117’ 
of very great importance and it is to be hoped that well drillers 
will find it possible to keep accurately labeled well samples in 
order to determine more definitely the distribution of this form¬ 
ation. 
APALACHICOLA GROUP. 
The Apalachicola group of formations is of a much less uni¬ 
form character than the Vicksburg and is also of less importance 
in connection with the water supply. A full description of this 
group of formations will be found in the Second Annual Report 
of this Survey, pp. 67-106. 
The formations which make up the Apalachicola group in¬ 
clude the Chattahoochee and Alum Bluff formations, well exposed 
along the Apalachicola River; the Hawthorne formation in Cen¬ 
tral Florida; and the Tampa formation in Southern Florida. The 
relative position of three of these, the Chattahoochee, the Haw¬ 
thorne and the Tampa formations, has not been definitely deter¬ 
mined, and they may be largely contemporaneous. The Alum 
Bluff formation lies above the Chattahoochee formation. The 
limestone of this group consists largely of impure clayey material 
which upon decay weathers to a sticky blue green clay. The 
Chattahoochee Limestone is difficult to recognize in well samples. 
Fossils in this formation are comparatively rare and such as occur 
are largely destroyed in drilling. In surface exposures it may 
be recognized by its lithologic character and by the characteristic 
cubical blocks into which some of the strata break upon exposure. 
The Apalachicola group has not been recognized from well 
drillings in East Florida. Clays taken by Mr. S. L. Hughes from 
the new city well at Jacksonville at the depth of 320 feet have 
a very close resemblance to the fuller’s earth clays which occur 
in the Apalachicola group, above the Chattahoochee Limestone. 
On the other hand, Matson obtained from Jacksonville a Miocene 
shark’s tooth from a well sample supposed to come from the 
depth of 496 feet. In order to determine more fully the area and 
extent of the Apalachicola group of formations in Eastern Florida 
it will be necessary to obtain large and carefully collected well 
samples. In Southern Florida the Apalachicola group is recog- 
