A PRELIMINARY REPORT ON CLAYS OE ELORIDA 
113 
The Alum Bluff formation of Miocene age is probably the most 
widely distributed of any of the formations exposed in Florida, extend¬ 
ing in a belt of variable width from northern Okaloosa County eastward 
to the northern part of the peninsula, thence southward to the Manatee 
River and the northern margin of the Everglades. It consists chiefly 
of interbedded sands, gravels, marls and clays, including the fuller’s 
earth, each of variable thickness and extent. These sediments are often 
cross-bedded indicating conflicting currents. They represent terrestrial, 
fresh-water and marine shallow-water conditions of sedimentation. The 
clays are usually thin, sandy, and variable in lateral extent. The Alum 
Bluff formation doubtless represents conditions of sedimentation not 
very different from those in operation in Florida at the present time. 
The fuller’s earth deposits are confined to a limited area in Gadsden 
and Leon counties, a smaller area in Manatee County, and isolated 
deposits in Marion and Alachua counties. 
Overlying much of the fuller’s earth in Gadsden County are two 
strata of clay. A section in one of the Floridin Company’s mines near 
Quincy shows the following: 
Soil and surface sand. 5 feet 
Unconformity . 
Clay, green, plastic..... 3 feet 
Apparent unconformity . 
Clay, greenish, sandy. 8 feet 
Fuller’s earth. 
An exposure on the highway about one mile east of Quincy, how¬ 
ever, exhibits only one stratum of clay. This is greenish in color and 
plastic. In other localities the clays above the fuller’s earth are absent. 
In the vicinity of Quincy this clay has formerly been used for the manu¬ 
facture of common brick and is very suitable for that purpose. 
In the vicinity of White Springs the Alum Bluff clays are promi¬ 
nent. At the bridge across the Suwannee River the following section 
was observed: 
Sand and soil (Pleistocene) . 6 feet 
Unconformity . 
Green, plastic, jointed clay. 8 feet 
Sand and marls. ? 
An exposure on the White Springs-Lake City highway, about two 
miles northwest of Lake City, exhibited the following sections: 
