SOME FLORIDA LAKES AND LAKE BASINS. 1 25 



iuriderground water than below this level. The term "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" is applied to that part lying immediately below this 

 level. According to Van Hise "the most characteristic reaction of 

 the belt of weathering is solution. In contrast with this the most 

 characteristic reaction in the belt of cementation is deposited 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 of 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. 

 LAKE lAMONIA. 



Lake lamonia 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 6,500 acres. Except at the west end, where 

 it joins the Ocklocknee River, the lake is largely surrounded by the 



♦Treatise on Metamorphism Mon. U. S. Geol. Survey, XLVII, p. 165, 1904. 



