124 FLORIDA GEOLOGICAL SURVEY-NINTH ANNUAL REPORT. 
through these streams into the St. Marks River. The. formation 
of sinks diverted the drainage to a subterranean course, the west 
end of the basin having been reduced to a level somewhat lower 
than the east end. The further enlargement of the. basin is being 
carried on through the formation of sinks along the border. The 
largest of the newly formed sinks is found near the present drainage 
sink. The. actual level of this basin at the present time is about 40 
feet above sea, while the original plateau was more than 200 feet 
above sea. 
MICCOSUKEE BASIN 
Miccosukee Basin, or Lake Miccosukee, lies between Leon and 
Jefferson counties, the west border of the lake forming the county 
line. A small arm of the lake, however, near the north end reaches 
into Leon County. This basin has a total area of about 5,000 
acres. I11 its northern part the basin is bordered by sharply defined 
bluffs, which rise, from 50 to 75 or 100 feet above the lake bottom. 
Farther south these bluffs fall back and give place to a gradual rise 
of elevation from the lake border. At the south end bluffs are 
lacking. A drain known as Miccosukee drain enters from the east 
side. This drain consists of a low, swampy are.a from one-fourth 
to three-fourths mile in width. This swamp land supports a thick 
growth of hardwood trees. When full the basin is covered with 
water to a depth of from 2 to 5 feet. Toward the south end around 
the border of the lake grass and button bushes project above the 
water even when the lake is full. 
The sink of Lake Miccosukee is located near the northwest cor¬ 
ner of the basin, and is bordered by a bluff having an elevation of 
from 75 to 100 feet. Landslides along the border of the sink show 
recent enlargements of the basin. Numerous sinks are found along 
the border of the lake at this locality, showing enlargement of the 
lake basin through subsidence. The greatest depth of water in the 
sink when examined September 7, 1509, was 38 feet. A channel 
ieads back from this sink across the prairie in a southeasterly direc¬ 
tion. This channel has cut to a depth of from twenty to twenty-five 
feet. Followed back from the. sink the channel is of gradually re¬ 
duced depth, finally, at a distance of about two miles, merging into 
the general level of the lake bottom. When examined September 
8, 1909, this stream was carrying water into the sink at a rate esti¬ 
mated to be 200 gallons per minute. Notwithstanding the inflow 
