The Ocala Limestone is a late Eocene

Eocene

The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

 geologic formation

Geologic formation

A formation or geological formation is the fundamental unit of lithostratigraphy. A formation consists of a certain number of rock strata that have a comparable lithology, facies or other similar properties...

 of exposed limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

s near Ocala

Ocala, Florida

Ocala is a city in Marion County, Florida. As of 2007, the population recorded by the U.S. Census Bureau was 53,491. It is the county seat of Marion County, and the principal city of the Ocala, Florida Metropolitan Statistical Area, which had an estimated 2007 population of 324,857.-History:Ocala...

, Marion County, Florida

Marion County, Florida

Marion County is a county located in the U.S. state of Florida. The U.S. Census Bureau 2006 estimate for the county is 316,183. Its county seat is Ocala....

.

Age

Period: Paleogene

Paleogene

The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...

Epoch

Epoch (geology)

An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...

: Late Eocene

Eocene

The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

Faunal stage

Faunal stage

In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries.Rock...

: Late Clarkforkian

Clarkforkian

The Clarkforkian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 56,800,000 to 55,400,000 years BP lasting . It is usually considered to be within the Paleocene, more specifically the...

 through early Orellan

Orellan

The Orellan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 33,900,000 to 33,300,000 years BP, a period of . It is usually considered to fall within the Early Oligocene...

Absolute Age

Geochronology

Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...

: ~55.8 to ~33.9 mya, calculates to a period of approximately

Location

The Ocala Limestone is at or near the surface within the Ocala Karst District located in west-central to the northwestern part of the peninsula. It is also within the Dougherty Plain District in the north-central panhandle where it easily forms karst

KARST

Kilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after the Kras region in Slovenia and Northern Italy. It will consist of...

s. These karsts often have several feet (meters) of relief which dramatically influence the topography of the Ocala Karst District and the Dougherty Plain District. The area is abundant with disappearing streams and springs.

Composition

Formerly a geologic group, Ocala Limestone was downgraded to formation status by T.M. Scott in 1991. The Ocala Limestone consists of almost pure limestones with occasional dolostone

Dolostone

Dolostone or dolomite rock is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite. In old U.S.G.S. publications it was referred to as magnesian limestone. Most dolostone formed as a magnesium replacement of limestone or lime mud prior to lithification. It is...

s. It can be subdivided into both lower and upper facies

Facies

In geology, facies are a body of rock with specified characteristics. Ideally, a facies is a distinctive rock unit that forms under certain conditions of sedimentation, reflecting a particular process or environment....

 with the lower facie composed of a whiteish to cream-colored, fine to medium grained, poorly to moderately hard, fossil rich grainstone

Grainstone

Under the Dunham classification, grainstones are grain-supported carbonate sedimentary rocks that contain no micrite. The spaces between grains are filled with sparry cement.-References:...

 and packstone. The upper Ocala is white and somewhat weak and poorly sorted. Its extremely fossil rich grainstone, packstone and wackestone

Wackestone

Wackestone is a matrix-supported carbonate rock that contains over 10% allochems in a carbonate mud matrix. This is part of the Dunham classification of carbonate rocks. In the other widely used classification due to Folk, an equivalent description would be, for example, an oopelmicrite, where the...

 and some chert

Chert

Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...

 is common in the upper facies. Its permeable and transmissive properties allow it to form a vital portion of the Floridan Aquifer

Floridan Aquifer

The Floridan Aquifer is a portion of the principal artesian aquifer that extends into Florida and is composed of carbonate rock and located beneath the coastal regions of the Southeastern United States and is one of the world's most productive aquifers. It is under all of Florida as well as ...

.

Overlay

The Ocala Limestone overlies the Avon Park Formation

Avon Park Formation

The Avon Park Formation is a Middle Eocene geologic formation and is the oldest exposed sediments in Florida, United States.-Age:Period: PaleogeneEpoch: Middle Eocene~55.8 to 33.9 mya, calculates to a period of...

 and forms part of the intermediate confining unit/aquifer system. (USGS)

Fossils

• Foraminifers, Lepidocyclina
• Echinoids
• Bryozoa
  Bryozoa
  The Bryozoa, also known as Ectoprocta or commonly as moss animals, are a phylum of aquatic invertebrate animals. Typically about long, they are filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia...
  
  ns
• Mollusks
• Rare vertebrates