THE SOILS AND OTHER SURFACE RESIDUAL MATERIALS OF FLORIDA 
E. H. SELLARDS 
INTRODUCTION. 
FORMATIONS FROM WHICH THE SOILS OF FLORIDA ARE DERIVED. 
The following classification and description of the formations in 
Florida is adapted from the First and Second Annual Reports of 
the Survey with such additions as subsequent investigations have 
justified. In this brief review of the geology of the State it will be 
convenient to describe the various formations in chronological order 
beginning with the oldest or first formed. In this manner the sys¬ 
tematic arrangement of the formations is more readily kept in mind. 
The major divisions of geologic time are in order: Archeozoic, 
Proterozoic, Paleozoic Mesozoic, and Cenozoic. All of the forma¬ 
tions of Florida are included in the latest of these major divisions, 
the Cenozoic. 
The geologic periods represented in Florida are the Oligocene, 
Miocene, Pliocene, Pleistocene and Recent. The formations found 
in the State are listed in the table on page 9, and are briefly de¬ 
scribed in subsequent pages of the report. 
OLIGOCENE. 
The Oligocene, the earliest period recognized in Florida, includes 
two main divisions known as Lower and Upper Oligocene respec¬ 
tively. The Lower Oligocene includes the Vicksburg Limestone, 
which is the basal formation underlying Florida, and which from its 
great thickness and diversity in fauna and lithologic characters has 
sometimes been referred to as the Vicksburg Group of Limestones. 
The Upper Oligocene includes the Tampa, Hawthorne. Chattahoo¬ 
chee, and Alum Bluff formations, known collectively as the Apalach¬ 
icola Group. 
