OCKLOCKNEE AND AUCILLA RIVERS. 119 
parts solids in solution per million parts water.* Wakulla Spring 
alone flows approximately a million pounds of water per minute 
(122,000 gallons). Hence probably as much as 200 pounds of 
solids in solution reaches the ocean through this one spring per min¬ 
ute. It is impossible to estimate the total flow of all springs from 
this area or to estimate the total escape of solids in solution through 
all springs, but it may be seen that the amount now passing to the 
ocean in this way is very considerable for each day in the year. 
When it is remembered that this process is not only going on now 
but has continued for a very long period of time, the. total amount 
of solids so removed may be in a measure at least appreciated as 
quite sufficient to account for the solution basins that have been 
formed. Of the minerals thus removed calcium carbonate or lime¬ 
stone greatly predominates, exceeding the combined amount of all 
other minerals. 
A first effect of solution in the limestone is to develop cavities 
through the rock along the line of ready flow of underground water. 
These cavities gradually enlarge until the overlying material is no 
longer able to support its own weight and caves, thus forming a sink. 
The formation of a sink is a first step in the development of the 
many basins large and small occupied by these lakes. A sink 
usually retains connection with the underlying limestone for some 
time after its formation, and water entering the sink escapes into 
the limestone. Under these circumstances more or less of the 
material lying immediately around the sink is carried by surface 
wash through the sink. Moreover, the. large amount of water en¬ 
tering through the sink results in rapid solution in the limestone of 
that immediate vicinity. The result is frequently the formation of 
other sinks in proximity to the first. As the sinks become clogged 
or partly filled, new sinks form by this proce.ss, continually enlarging 
the basin. 
The large basins of this type are usually shallow water lakes 
which at times become entirely dry. It may be. readily understood, 
also, that a basin that at one stage of development is a shallow water 
lake may subsequently become permanently dry, the lake having 
become, drained by natural agencies. The smaller lakes, on the other 
hand, are usually relatively deep water lakes. 
*Fla. Geol. Survey, Bull. No. 1, p. 47, 1908. 
