SOME FLORIDA' LAKES AND LAKE BASINS. 
53 
ground waiter goes on more rapidly above the level of permanent 
underground water than below this level. The term 1 “belt of 
weathering” is commonly applied to that part of the earth’s crust 
lying above the underground water level; while the term “belt of 
cementation’' 1 is applied to that part lying immediately below this 
level. According to Van Hise “the most characteristic reaction ot 
the belt of weathering is solution. In contrast with this the most 
characteristic reaction in the belt of cementation is deposition in the 
openings of the rocks.”* The rapid solution in the belt of weather¬ 
ing is due to a number of causes. First of all the water in this 
part of the earth’s crust moves freely, while in the belt of cemen¬ 
tation the water often moves very slowly. Moreover water is cap¬ 
able under given conditions of carrying a definite amount of min¬ 
eral solids in solution and as the water from the surface enters 
the earth with little or no load, until it becomes saturated it takes 
materials into solution readily. 
In accordance with this principle it is found that the largest 
of these basins are, as a rule, reduced practically to the level of un¬ 
derground water. Many of the smaller basins, it is true, have not 
reached the permanent water level, and stand at varying heights 
above that level. The relation o'f the basins to the underground 
water has a practical bearing and will be referred to again in con¬ 
nection with methods of drainage of the lakes. 
DESCRIPTIONS OF TYPICAL LAKES. 
b 
LAKE IAMONIA. 
Lake Iamonia lies near the north line of Leon County. The 
lake basin is irregular in outline, but has an average width of 
from one to one and one-half miles. The total length of the lake 
is from twelve to thirteen miles. At its west end the lake basin 
connects with the swamp of the Ocklocknee River. During flood 
seasons the river overflows into the lake. Similarly a high stage in 
the lake results in an overflow into the river. Small tributary 
streams enter the lake from both the north and the south side as 
well as from the east end. The tributaries are small flat-bottomed 
streams which are dry, except during the rainy season. The lake 
fluctuates much according to the rainfall. The lake basin when full 
covers an area of about 6500 acres. Except at the west end, where 
*Treatise on Metamorphism Mon. U. S. Geol. Survey, XLVII, p. 165, 1904. 
