SOME FLORIDA LAKES AND LAKE BASINS.

to four miles. It contains about twelve thousand-acres. Low divides scarcely exceeding ten feet in elevation separate this basini from Kanapaha and other prairies on the west and from Levy, Ledwith, and numerous smaller jakes on the south, and from Newnans Lake on the northeast. The total area embraced within these various basins is not less than fifty square miles. For a map of this section the reader may consult the Arredondo topographic sheet of the U. S. Geological Survey.
When dry or nearly so, this basin supports a dense growth of grasses and weeds. On the more elevated and dryer parts dogfennel prevails, growing to a height of eight or ten feet, while on the lower and wetter parts of the basin maiden cane abounds.
The principal stream entering this basin is a creek flowing from Newnans Lake. This creek enters at the east side of the basin and flows west and northwest to the sink.
The "sink." of Alachua Basin is located in the northeast border. Two sinks occur here. The waters from these sinks enter the Vicksburg Limestone. The sinks are partly surrounded by bluffs rising to an elevation of thirty or forty feet above the general level of the basin. Numerous sinks occur along the border of the lake showing enlargement of the lake basin in this direction. The stream entering the more westerly of the two sinks was carrying water when examined in October, 1907, at an estimated rate of 20,000 gallons per minute. At this time the water level in the sink was only 2.01 feet above the general level of water in the Vicksburg Limestone as shown by the Gainesville city well,* indicating that the sink was carrying water at its full capacity or nearly so.
In November, I9O9, the water in the sink stood approximately one and one-half feet above the level of the water in the surrounding limestone.
During seasons of heavy rainfall the stream draining from Newnans Lake and other smaller streams# carry water so rapidly that the water is unable to escape through the sink as rapidly as it flows in. Under these conditions the basin fills, becoming temporarily a lake. It is probable also that the drainage sink becomes more or less completely clogged at times retarding the escape of water, and in this case the prairie may continue as a lake through a succession of years.
Variation in this lake has been more or less perfectly recorded since the time of the earliest settlements in this section. When
*Bull No. I, Fla. Geol. Survey., p. 60, 1908.

63