28 
FLORIDA STAFF GEOLOGICAL SURVEY. 
the Atlantic Coast Line Railroad, the Seaboard Air Line Railway, the 
Florida East Coast Railway and the Louisville and Nashville Rail¬ 
road, in Jacksonville, Wilmington, Norfolk and Louisville, have 
allowed access to their profiles and other records, which gave valuable 
information for use in the construction of the topographic map of 
the State. 
At the time when the field work for this report was begun Mr. 
Samuel Sanford was engaged in geologic work for the Florida East 
Coast Railway. The task of investigating the geology of the Keys 
and the southern end of the State was entrusted to him. The results 
of Mr. Sanford’s work are incorporated in a subsequent chapter. 
TOPOGRAPHY AND DRAINAGE. 
General Topographic Features:—-While Florida is a region of com¬ 
parative slight relief, its surface configuration presents considerable 
diversity, ranging from the nearly level plain in the coastal region 
and the Everglades to the deeply dissected upland in the northern 
part of the State, where much of the surface is trenched by steep 
walled valleys, and the highlands of the peninsula where the surface 
often consists of a series of more or less rounded depressions separated 
by narrow divides. The range in altitude varies from sea level along 
the coast to over 200 feet above tide at various points on the ridge 
which forms the center of the peninsula and to about 300 feet above 
the same datum near the northern boundaries of Gadsden, Walton, 
Santa Rosa and Escambia Counties. 
The accompanying topographic map (in pocket) is intended to 
show the approximate areas of land which lie above and below certain 
altitudes. The datum plane is mean sea level, and the contour lines 
show the variations in altitude for each fifty feet. This map embodies 
the results of the earlier topographic surveys, the river surveys of 
the U. S. Army engineers, and the various railroad surveys, together 
with a large number of barometric determinations which were made 
during the progress of the field work. While the exact location of 
the contours is sometimes more or less uncertain, it is believed tha-t 
they are sufficiently accurate to give a good idea of the relative areas 
of different altitudes, and to present a general plan of the broader 
topographic features of the State. Owing to the small scale of the 
map, it was necessary to omit such minor details as sink-holes, valleys 
of small streams, narrow ridges and small, more or less, isolated ele¬ 
vations. The U. S. Geological Survey has already published detailed 
maps of certain parts of the peninsula, and to these the reader is 
referred for local information. 1 
1 Arredondo, Citra, Dunnellon, Ocala, Panasoffkee, Tsala Apopka and 
Williston sheets. 
