Torreya Formation
Encyclopedia
The Torreya Formation is a Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 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...

 with an outcrop
Outcrop
An outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. -Features:Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial deposits are covered by a mantle of soil and vegetation and cannot be...

 in North Florida
North Florida
North Florida refers to the northernmost part of the U.S. state of Florida, including some counties that border the state of Georgia. It also borders the Big Bend with Madison County and Taylor County to the east and the Central Florida region to its south....

. It is within the Hawthorn Group
Hawthorn Group
The Hawthorn Group is a Late Oligocene to Pliocene grouping of several geologic formations and members in North Florida, United States.The Hawthorn Group was originally called the Waldo Formation in 1887 by L. C...

.

Age

Period: Neogene
Neogene
The Neogene is a geologic period and system in the International Commission on Stratigraphy Geologic Timescale starting 23.03 ± 0.05 million years ago and ending 2.588 million years ago...



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...

: Early Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...



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...

: Aquitanian
Aquitanian
Aquitanian could refer to:*Aquitanian age, a geological age, the first stage of the Miocene Epoch*Aquitanian language, an ancient language spoken in the region later known as Gascony* Anything originating from Aquitaine, a region of France....

 through early Messinian
Messinian
The Messinian is in the geologic timescale the last age or uppermost stage of the Miocene. It spans the time between 7.246 ± 0.005 Ma and 5.332 ± 0.005 Ma...

 ~19—15.3 mya, calculates to a period of

Composition

The Torreya Formation is exposed or near the surface from Gadsden County, Florida
Gadsden County, Florida
Gadsden County is a county located in the panhandle of the U.S. state of Florida. As of the 2000 census, the population was 45,087. The U.S. Census Bureau 2005 estimate for the county is 46,428 . Its county seat is Quincy, Florida. Gadsden County is the only predominantly African-American...

 on the west. Its eastern extent is western-most Hamilton County, Florida
Hamilton County, Florida
Hamilton County is a county located in the U.S. state of Florida. As of 2000, the population was 13,327. The U.S. Census Bureau 2005 estimate for the county is 13,983 . Its county seat is Jasper, Florida.- History :...

. It includes the counties of Liberty
Liberty County, Florida
Liberty County is a county located in the state of Florida. Its population was estimated in 2005 as 7,733. Its most populous incorporated area and county seat is Bristol....

, Leon
Leon County, Florida
Leon County is a county located in the state of Florida, named after the Spanish explorer Juan Ponce de León. At the 2010 Census, the population was 275,487. The county seat of Leon County is Tallahassee which also serves as the state capital. The county seat is home to two of Florida's major...

, Jefferson
Jefferson County, Florida
Jefferson County is a county located in the U.S. state of Florida. As of 2000, the population is 12,902. The U.S. Census Bureau 2005 estimate for the county is 14,490 . Its county seat is Monticello, Florida....

, Madison
Madison County, Florida
Madison County is a county located in the state of Florida. As of 2000, the population was 18,733. The U.S. Census Bureau 2005 estimate for the county is 19,902. Its county seat is Madison, Florida. Madison County is one of Florida's five dry counties....

, and Wakulla
Wakulla County, Florida
Wakulla County is a county located in the U.S. state of Florida. As of 2000, the population was 22,863. The U.S. Census Bureau 2005 estimate for the county was 28,212 people...

. It is informally subdivided into a lower carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

 unit and an upper siliciclastic
Siliciclastic
Siliciclastic rocks are clastic noncarbonate sedimentary rocks that are almost exclusively silica-bearing, either as forms of quartz or other silicate minerals. All siliciclastic rocks are formed by inorganic processes, or deposited through some mechanical process, such as stream deposits that are...

 unit. The majority of Torreya Formation outcrops expose the siliciclastic part of the unit.

Lithography

The siliciclastics are quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

 and vary in color from white to light olive gray. They are unconsolidated to poorly indurated (hard), slightly clayey sands with minor phosphate to light gray to bluish gray, poorly consolidated, variably silty clay (Dogtown Member). The siliciclastics are sporadically fossiliferous and often contain oyster
Oyster
The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....

 shells as found in the Seaboard Air Line Railroad site.

The carbonate sediments contain phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...

 and are white to light olive gray. They are generally not hard but variably sandy with clay. This unit is also fossiliferous with both molds and casts and includes limestone (mudstone
Mudstone
Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...

 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...

). The limestones often grade into calcareous
Calcareous
Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.-In zoology:...

-cemented sands.

The Dogtown Member is time transgressive with older aged material at ~15.9—15.3 Ma. and found in the south while the younger material is in the north.

Overlay

The Torreya Formation overlies 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 ...

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

Paleofauna

Barstovian land-mammal fauna found in northern Gadsden County dated 14.7—16.6 Ma. Paleofauna based on the fossils from: Gadsden County paleontological sites
Gadsden County, Florida paleontological sites
The Gadsden County paleontological sites are assemblages of Early Miocene invertebrates and vertebrates occurring in Gadsden County, Florida, United States.-Age:Era: NeogenePeriod: Early Miocene...

, Leon County paleontological sites, Jefferson County paleontological sites
Jefferson County, Florida paleontological sites
The Jefferson County, Florida paleontological sites are assemblages of Mid-Miocene to Late Pleistocene vertebrates from Jefferson County, Florida, United States.-Age:Era: Neogene...

, and Hamilton County paleontological sites.

Bivalve
  • Ostrea
    Ostrea
    Ostrea is a genus of oyster in the family Ostreidae. Evidence of a number of species of this genus in the geological fossil record demonstrates the ancient nature of this genus, and also gives testimony to the species that co-existed with members of the Ostrea genus...

     normalis

Fish
  • Myliobatis
    Myliobatis
    Myliobatis is a genus of eagle rays in the family Myliobatidae.-Species:* Genus Myliobatis** Myliobatis aquila ** Myliobatis australis Macleay, 1881...

    (Rays)
  • Carcharhinidae (Sharks)
  • Pristis (Sawfish)
  • Pogonias cromis

Reptiles
  • Alligatoridae
    Alligatoridae
    Alligatoridae is a family of crocodylians that includes alligators and caimans.- True alligators :Alligators proper occur in the fluvial deposits of the age of the Upper Chalk in Europe, where they did not die out until the Pliocene age. The true alligators are now restricted to two species, A...

    (Alligator)
  • Boidae (Boa)
  • Ciconiidae (Turtle)
  • Crocodylidae (Crocodile)
  • Geochelone
    Geochelone
    Geochelone is a genus of tortoises.Geochelone tortoises, which are also known as typical tortoises or terrestrial turtles, can be found in Africa and Asia. They primarily eat plants.The genus consists of three extant species:...

    (Turtle)
  • Pseudemys
    Pseudemys
    Pseudemys is a genus of large, herbivorous, freshwater turtles of the eastern United States. They are often referred to as cooters, which stems from kuta, the word for turtle in the Bambara and Malinké languages, brought to America by African slaves....

    (Turtle)

Birds
  • Gruidae (Crane)

Mammals
  • Aletomeryx
    Aletomeryx
    Aletomeryx is an extinct genus of Artiodactyla, of the family Palaeomerycidae, endemic to North America from the early Miocene epoch 20.6—16.3 Ma, existing for approximately .-Taxonomy:...

    and A. gracilis
  • Amphicyon
    Amphicyon
    Amphicyon is an extinct genus of large carnivorous bone-crushing mammals, known as bear-dogs, of the family Amphicyonidae, subfamily Amphicyoninae, from the Aquitanian Epoch until the Tortonian...

    and A. pontoni (dog-like carnivore)
  • Anchitherium
    Anchitherium
    Anchitherium was a fossil horse with a three-toed hoof.Anchitherium was a browsing horse that originated in the early Miocene of North America and subsequently dispersed to Europe and Asia, where it gave rise to the larger bodied genus Sinohippus...

    and A. clarencei (Horse)
  • Archaeohippus
    Archaeohippus
    Archaeohippus is an extinct three toed member of the family Equidae known from fossils of Late Oligocene to early Miocene age. The genus is noted for several distinct skeletal features. The skull possesses deeply pocketed fossa in a notably long preorbital region. The genus is considered an...

    and A. blackbergi (Horse)
  • Borophaginae
    Borophaginae
    The subfamily Borophaginae is an extinct group of canids called "bone crushing dogs" that were endemic to North America during the Oligocene to Pliocene and lived roughly 36—2.5 million years ago and existing for approximately .-Origin:...

    (Bone-crushing dog)
  • Camelidae (Camel)
  • Canidae
    Canidae
    Canidae is the biological family of carnivorous and omnivorous mammals that includes wolves, foxes, jackals, coyotes, and domestic dogs. A member of this family is called a canid . The Canidae family is divided into two tribes: Canini and Vulpini...

    (Canine unknown)
  • Equidae
    Equidae
    Equidae is the taxonomic family of horses and related animals, including the extant horses, donkeys, and zebras, and many other species known only from fossils. All extant species are in the genus Equus...

    (Horse)
  • Floridatragulus
    Floridatragulus
    Floridatragulus is an extinct genus of Camelid. It lived in North America during the Miocene, about 20.6—15.9 mya, existing for approximately .-Taxonomy:Floridatragulus was named by White...

    (Camel)
  • Harrymys magnus (Mouse)
  • Merychippus
    Merychippus
    Merychippus is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene from 20.43—10.3 Ma living for approximately .It had three toes on each foot and is the first horse known to have grazed...

     and M. gunteri (Horse)
  • Nanosiren (Sea Cow)
  • Nothokemas
    Nothokemas
    Nothokemas is an extinct genus of terrestrial herbivore the family Camelidae, endemic to North America from the Oligocene through Miocene 30.8— 20.430 mya, existing for approximately .-Taxonomy:...

    and N. floridanus (Camel)
  • Osbornodon iamonensis
    Osbornodon iamonensis
    Osbornodon iamonensis is an extinct species of bone-crushing Hesperocyoninae, a predecessor of modern dogs that were endemic to North America and which lived from the Orellan age of the Early Oligocene to Early Miocene epoch 23.6—16.3 Ma and existed for approximately .O. iamonensis was named by E. H...

    (Proto-dog)
  • Parahippus leonensis
    Parahippus leonensis
    Parahippus leonensis is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene from 23.030—16.3 Ma living for approximately .Parahippus leonensis was named for Leon or more specifically Leon County, Florida....

    (Horse)
  • Proheteromys and P. floridanus (Rodent)
  • Prosynthetoceras
    Prosynthetoceras
    Prosynthetoceras is an extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America from the early Miocene epoch 20.6—13.6 Ma, existing for approximately .-Taxonomy:...

    and P. texanus (Deer-like ungulate)
  • Procyoninae (Mustelid)
  • Merycoidodontidae (Hog)
  • Mesogaulus (Horned gopher)
  • Rhinocerotidae (Rhinoceros)
  • Ruminantia
    Ruminantia
    Ruminantia includes many of the well-known large grazing or browsing mammals: among them cattle, goats, sheep, deer, and antelope. All members of the Ruminantia are ruminants: they digest food in two steps, chewing and swallowing in the normal way to begin with, and then regurgitating the...

    (Ruminant basal)
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