Lake Tulane in Florida is one of numerous natural lakes that occupy

sinkhole A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are locally also known as ''vrtače'' and shakeholes, and to openi ...

s, which were formed by the dissolution of

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

at depth. Lake Wales Ridge, within which Tulane Lake lies, is a linear highland that consists of unconsolidated

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

s of the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

sediments that overlie limestone, which was dissolved by groundwater and collapsed to form Tulane Lake. It is oblong in shape, has a surface area of and has a maximum depth of .Beck, B. (1986) ''Sinkholes in Florida: an Introduction.'' Report No. 85-86-4. The Florida Sinkhole Research Institute, University of Central Florida, Orlando, Florida.Grimm, E.C., G.L. Jacobson, W.A, Watts, B.C.S. Hansen, and K.A. Maasch (1993) ''A 50,000-Year Record of Climate Oscillations from Florida and Its Temporal Correlation with the Heinrich Events.'' Science. v. 261, no. 5118, pp. 198-200.White, W.A. (1958) ''Some geomorphic features of central peninsular Florida.'' Geological Bulletin no. 41, Florida Geological Survey, Tallahassee. It is surrounded by residential housing in

Avon Park, Florida Avon Park is a city in Highlands County, Florida, United States. As of the 2010 census the population was 8,836, and in 2018 the estimated population was 10,695. It is the oldest city in Highlands County, and was named after Stratford-upon-Avon, ...

. The organic-rich sediments, which underlie the bottom of Lake Tulane, provide one of the few records of ancient climates within eastern North America that extends beyond the late glacial period (~ 15,000 cal years BP). Cores from the bottom of Lake Tulane have yielded a record of paleoclimates and paleovegetation, which date back to before 60,000 BP. The Pre-

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

pollen record shows alternating periods of Pinus (

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accep ...

)-dominated and Quercus-Ambrosia (

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

ragweed Ragweeds are flowering plants in the genus ''Ambrosia'' in the aster family, Asteraceae. They are distributed in the tropical and subtropical regions of the Americas, especially North America,Heinrich event A Heinrich event is a natural phenomenon in which large groups of icebergs break off from glaciers and traverse the North Atlantic. First described by marine geologist Hartmut Heinrich (Heinrich, H., 1988), they occurred during five of the last ...

s H1 to H5. This correlation demonstrates a linkage between continental and oceanic climate events. The periods of Pinus-dominated vegetation are interpreted to represent periods of relatively high precipitation associated with relatively warm waters in the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

. The periods of Quercus-Ambrosia-dominated vegetation are interpreted to represent period of arid climate associated with periods when the Gulf of Mexico and the North

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

were cooled by glacial meltwaters.Grimm, E.C., W.A. Watts, G.L. Jacobson Jr., B.C.S. Hansen, H.R. Almquist, and A.C. Dieffenbacher-Krall (2006) ''Evidence for warm wet Heinrich events in Florida.'' Quaternary Science Reviews. vol. 25, pp. 2197–2211. Lake Tulane is used for swimming, boating and fishing. There is a public boat ramp on its west side and a public swimming beach on its south side. A person leaving a comment in the Fishing Works website rated the fishing at the lake as excellent.Anonymous (nd
Fishing Works Website; "Lakes of Highlands County"
PDF file.

References

{{authority control

Tulane Tulane University, officially the Tulane University of Louisiana, is a private research university in New Orleans, Louisiana. Founded as the Medical College of Louisiana in 1834 by seven young medical doctors, it turned into a comprehensive pub ...