The Bone Valley Formation is a
geologic formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
in
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, a ...
. It is sometimes classified as the upper member of the
Peace River Formation of the
Hawthorn Group.
It contains economically important
phosphorite
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxi ...
deposits that are mined in west-central Florida, as well as rich assemblages of
vertebrate
Vertebrates () comprise all animal taxon, taxa within the subphylum Vertebrata () (chordates with vertebral column, backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the ...
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
s.
Lithology
The Bone Valley Formation consists of
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 soil texture, textur ...
y
marl that contains pebbles of
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phosph ...
and
chert
Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a ...
, fragments of bone, and other organic remains. The finer grained material is soft and plastic when wet, but hardens when dry.
[Matson, G.C. and Clapp, F.G. 1909. A preliminary report on the geology of Florida with special reference to the stratigraphy. Florida Geological Survey Annual Report, no. 2, p. 13-173.]
Age
The Bone Valley Formation contains
mammal fossils and its age has been determined by mammalian
biostratigraphy
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictionary of Bio ...
.
Period:
Neogene
The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago (Mya) to the beginning of the present Quaternary Period Mya. ...
Epoch
In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured.
The moment of epoch is usually decided by ...
:
Middle Miocene to
Early Pliocene
Early may refer to:
History
* The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.:
** Early Christianity
** Early modern Europe
Places in the United States
* Early, Iowa
* Early, Texas
* Early ...
North American land mammal age
The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna beginning during the Late Cretaceous and continuing through to the present. These periods are referred to as ages or intervals (or stages when re ...
:
Barstovian
The Barstovian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 16,300,000 to 13,600,000 years BP, a period of . It is usu ...
to
Hemphillian
The Hemphillian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered ...
[Morgan, G.S. 1993. Mammalian biochronology and marine-nonmarine correlations in the Neogene of Florida. In: Zullo, V.A. and others, The Neogene of Florida and adjacent regions; proceedings of the Third Bald Head Island conference on coastal plains geology, Hilton Head Island, SC, November 4–8, 1992. Florida Geological Survey Special Publication no. 37, p. 55-66.]
Paleontology
The Bone Valley Formation includes a diverse assemblage of vertebrate fossils. These include remains of
sea turtle
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhe ...
s,
equine
Equinae is a subfamily of the family Equidae, which have lived worldwide (except Indonesia and Australia) from the Hemingfordian stage of the Early Miocene (16 million years ago) onwards. They are thought to be a monophyletic grouping.B. J. Mac ...
s,
felines
The Felinae are a subfamily of the family Felidae. This subfamily comprises the small cats having a bony hyoid, because of which they are able to purr but not roar.
Other authors have proposed an alternative definition for this subfamily: as ...
,
peccaries
A peccary (also javelina or skunk pig) is a medium-sized, pig-like hoofed mammal of the family Tayassuidae (New World pigs). They are found throughout Central and South America, Trinidad in the Caribbean, and in the southwestern area of No ...
,
[Wright, D. B. and Webb, S. D. 1984. Primitive '']Mylohyus
''Mylohyus'' is an extinct genus of peccary found in North and Central America. It first evolved during the Late Miocene and became extinct at the end of the Pleistocene, around 12,000 years ago.
Six species were known, the most famous being ''M ...
'' (Artiodactyla
The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poste ...
: Tayassuidae) from the late Hemphillian Bone Valley of Florida. Journal of Vertebrate Paleontology, 3(3), 152-159. and others.
See also
*
Bone Valley
The Bone Valley is a region of central Florida, encompassing portions of present-day Hardee, Hillsborough, Manatee, and Polk counties, in which phosphate is mined for use in the production of agricultural fertilizer. Florida currently contains th ...
*
List of fossiliferous stratigraphic units in Florida
See also
* Paleontology in Florida
References
*
{{DEFAULTSORT:Fossiliferous stratigraphic units in Florida
Florida
Stratigraphic units
Stratigraphy of Florida
Florida geography-related lists
United States geology-related lists ...
References
* {{cite web, title= Fossilworks: Gateway to the Paleobiology Database, author= ((Various Contributors to the Paleobiology Database)), url= http://www.fossilworks.org/cgi-bin/bridge.pl?action=home, access-date= 17 December 2021
Neogene Florida
Natural history of Florida