242 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT. 
pounds of iron. Observation discloses the fact that it is formed at 
or under the permanent water-table level. 
The Leon sand is found in the eastern half of the area, where it 
occupies the flat situation known as “scrub palmetto flatwoods.” 
The tree growth is mainly longleaf pine and in places shortleaf pine, 
the trees being generally stunted and sparse. Its characteristic un¬ 
dergrowth is scrub saw palmetto, with some gallberry bushes, grass¬ 
es, and sedges. These flats occur along the larger streams and 
lakes. One area lies in the vicinity of Silver Springs Run, but 
the largest development of this phase is in the Withlacoochee 
Valley, east of the river and around Lake Panasoffkee, in the 
vicinity of Coleman. The elevation of these flats is 50 to 60 feet 
above sea level. While generally flat, they occasionally show some 
slight undulation, caused by trough depressions or depressed basins 
and by sink-hole ponds. Here and 1 there, especially in the southern 
part of the area, some rock outcrops are found, consisting of the 
flinty part of the underlying limestones. 
There is some variation in the type where it occurs in the ham¬ 
mocks, the soil being darker than in the flatwood areas, owing to a 
greater proportion of organic matter. Also, the hardpan substratum 
is of less frequent occurrence, being found only in small spots and is 
deeper or entirely absent in the soil profile. In some places the ma¬ 
terial lies directly upon rock. The tree growth on these hammocks 
consists of live oak and water oak, magnolia, cabbage palmetto, and 
some other hardwoods. The largest hammock areas are found in 
basins in the “high hammock” land, which are spoken of as “sand 
scrub.” The tree growth here is large, owing in part either to near¬ 
ness of the underlying clays or to the good moisture conditions. 
Flinty rock outcrops are frequent. Some hammock growth is also 
found forming rims around ponds in the pine-woods areas. 
A phase of this type occurs in the ponds and prairies shown on 
the topographic base as intermittently wet areas and locally called 
“sand ponds.” The sand mantle here is gray or dark gray and is 
underlain at a few inches by a brown “hardpan layer.” These ponds 
are very leachy, holding water only a short time. Dog fennel is the 
principal growth. These depressions occur in the flatwoods area and 
in the basins in the rolling sandy lands. The material constituting 
this soil undoubtedly is derived directly from originally unconsoli¬ 
dated Coastal Plain deposits. 
The Leon sand is generally recognized as a very poor and unde- 
