The Bogotá Formation ( es, Formación Bogotá, E
1-2b, Tpb, Pgb) is a
geological 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 ...
of the
Eastern Hills and
Bogotá savanna
The Bogotá savanna is a montane savanna, located in the southwestern part of the Altiplano Cundiboyacense in the center of Colombia. The Bogotá savanna has an extent of and an average altitude of . The savanna is situated in the Eastern Ran ...
on the
Altiplano Cundiboyacense
The Altiplano Cundiboyacense () is a high plateau located in the Eastern Cordillera of the Colombian Andes covering parts of the departments of Cundinamarca and Boyacá. The altiplano corresponds to the ancient territory of the Muisca. The Alt ...
,
Eastern Ranges
The Eastern Ranges is an Australian rules football team in the NAB League, the Victorian statewide under-18s competition.
The club is a founding member of the competition (1992) and has produced several players for the Australian Football Leag ...
of the
Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the ...
n
Andes
The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...
. The predominantly
shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especiall ...
and
siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...
formation, with
sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicat ...
beds intercalated, dates to the
Paleogene
The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( Mya) to the beginning o ...
period;
Upper Paleocene
Upper may refer to:
* Shoe upper or ''vamp'', the part of a shoe on the top of the foot
* Stimulant, drugs which induce temporary improvements in either mental or physical function or both
* ''Upper'', the original film title for the 2013 found f ...
to
Lower Eocene epochs, with an age range of 61.66 to 52.5 Ma, spanning the
Paleocene–Eocene Thermal Maximum
The Paleocene–Eocene thermal maximum (PETM), alternatively (ETM1), and formerly known as the "Initial Eocene" or "", was a time period with a more than 5–8 °C global average temperature rise across the event. This climate event o ...
. The thickness of the Bogotá Formation ranges from near
Tunja
Tunja () is a city on the Eastern Ranges of the Colombian Andes, in the region known as the Altiplano Cundiboyacense, 130 km northeast of Bogotá. In 2018 it had a population of 172,548 inhabitants. It is the capital of Boyacá departmen ...
to near Bogotá. Fossils of the
ungulate
Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ...
''
Etayoa bacatensis'' have been found in the Bogotá Formation, as well as numerous reptiles, unnamed as of 2017.
Etymology
The formation was first described by
Hettner in 1892,
[Acosta & Ulloa, 2002, p.59] then by
Hubach in 1931, 1945 and 1957, and named in 1963 by
Julivert after the Colombian capital
Bogotá
Bogotá (, also , , ), officially Bogotá, Distrito Capital, abbreviated Bogotá, D.C., and formerly known as Santa Fe de Bogotá (; ) during the Spanish period and between 1991 and 2000, is the capital city of Colombia, and one of the larges ...
and
its savanna.
[Montoya & Reyes, 2005, p.57]
Description
Lithologies
The Bogotá Formation consists mainly of grayish-red, locally purplish, commonly greenish-gray, generally poorly stratified
mudstone
Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology.' ...
and silty
claystone
Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone, slate, and shale. Most of the particles of which the stone is composed are less than and are too ...
.
Lithic arenite sandstone lenses, ranging from fine- to medium-grained, generally
friable
Friability ( ), the condition of being friable, describes the tendency of a solid substance to break into smaller pieces under duress or contact, especially by rubbing. The opposite of friable is indurate.
Substances that are designated hazardous, ...
and variegated, are local constituents.
Carbonaceous material is present as thin beds of low-grade argillaceous
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when ...
, north of Bogotá.
[Bayona et al., 2010, p.5][McLaughlin, 1970, p.15] Fossil remains of ''
Etaoya bacatensis'', named after Colombian geologist
Fernando Etayo
Fernando Etayo Serna is a Colombian paleontologist and geologist. His contributions on the paleontology in Colombia has been mainly on the descriptions of ammonites and Etayo has helped describing many fossiliferous geologic formations of Colomb ...
and the
indigenous name for the Bogotá savanna,
Bacatá
Bacatá is the name given to the main settlement of the Muisca Confederation on the Bogotá savanna. It mostly refers to an area, rather than an individual village, although the name is also found in texts referring to the modern settlement of ...
,
[Villarroel, 1987, p.242] have been found in
Ciudad Bolívar
Ciudad Bolívar (; Spanish for "Bolivar City"), formerly known as Angostura and St. Thomas de Guyana, is the capital of Venezuela's southeastern Bolívar State. It lies at the spot where the Orinoco River narrows to about in width, is the si ...
, close to the type locality of the Bogotá Formation.
[''Etayoa bacatensis'']
at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world.
History
Fossilworks was crea ...
.org Additionally, macroflora of ''
Palaeophytocrene hammenii'', named after Dutch botanist
Thomas van der Hammen
Thomas van der Hammen (Schiedam, Netherlands, 27 September 1924 - Chía, Colombia, 12 March 2010) was a Dutch palaeontologist, botanist and geologist. He had published more than 160 works in five languages.[pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...]
of ''
Foveotriletes margaritae'', ''
Proxapertites operculatus'' and ''
Foveotricolpites perforatus'' have been found, used for dating the formation.
[ Other pollen and flora, as '' Ulmoideipites krempii'', '' Carpolithus'', '' Anemocardium margaritae'', and '' Hickeycarpum peltatum'' have been found in the Bogotá Formation.][Herrera et al., 2014, pp.204-209] The abundant paleosol
In the geosciences, paleosol (''palaeosol'' in Great Britain and Australia) is an ancient soil that formed in the past. The precise definition of the term in geology and paleontology is slightly different from its use in soil science.
In geolo ...
s of the Bogotá Formation show an increase in chemical weathering across the Paleocene-Eocene (P-E) transition; the Paleocene–Eocene Thermal Maximum
The Paleocene–Eocene thermal maximum (PETM), alternatively (ETM1), and formerly known as the "Initial Eocene" or "", was a time period with a more than 5–8 °C global average temperature rise across the event. This climate event o ...
.[Morón et al., 2013]
Later analysis has found several other species, such as pleurodire turtles, found at the Doña Juana dump,[Cadena, 2014, p.334] dyrosaurid mesoeucrocodylians, boid snakes, dipnoan fishes, frogs, lizards, sebecid crocodyliforms and 11 fossils of mammals.[Bloch et al., 2008] The find of a derived snake in the Lower Eocene section of the formation represents the oldest New World record.[Head et al., 2011] The finds of iguanians, including the fossil record of hoplocercines, and boine, caenophidian, and ungaliophiine snakes, indicate a tropical forest environment, present just before the Early Eocene Climatic Optimum (EECO).[Head et al., 2012] The faunal distribution has been correlated to the '' Carodnia''-, '' Amphidolops''-, and '' Wainka''-bearing Peñas Coloradas Formation of the Golfo San Jorge Basin
The Golfo San Jorge Basin ( es, Cuenca del Golfo San Jorge) is a hydrocarbon-rich sedimentary basin located in eastern Patagonia, Argentina. The basin covers the entire San Jorge Gulf and an inland area west of it, having one half located in San ...
in Patagonia
Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and g ...
, Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
.[Woodburne et al., 2014, p.60]
Stratigraphy and depositional environment
The Bogotá Formation, with a thickness of close to Tunja
Tunja () is a city on the Eastern Ranges of the Colombian Andes, in the region known as the Altiplano Cundiboyacense, 130 km northeast of Bogotá. In 2018 it had a population of 172,548 inhabitants. It is the capital of Boyacá departmen ...
to near Bogotá,[Bayona et al., 2013, p.8][Guerrero Uscátegui, 1992, p.5] overlies the Cacho Formation and is overlain by the Regadera Formation. The age has been estimated to be Late Paleocene
The Thanetian is, in the ICS Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or Series. It spans the time between . The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age (p ...
to Early Eocene.[Montoya & Reyes, 2005, p.60] The middle part of the succession has been dated using detrital zircon
Zircon () is a mineral belonging to the group of nesosilicates and is a source of the metal zirconium. Its chemical name is zirconium(IV) silicate, and its corresponding chemical formula is Zr SiO4. An empirical formula showing some of t ...
s at 56.2 ± 1.6 Ma.[Bayona et al., 2012, p.104] The spread of ages based on zircons has been reported from 60.96 ± 0.7 to 53.6 ± 1.1 Ma.[Bayona et al., 2012, p.103] The Bogotá Formation is laterally equivalent with the shales of the Socha Formation, the San Fernando Formation, the El Limbo Formation,[ Los Cuervos Formation,][Figures Bayona et al.]
/ref> and the fossil-rich Cerrejón Formation
The Cerrejón Formation is a geologic formation in Colombia dating back to the Middle-Late Paleocene. It is found in the El Cerrejón sub-basin of the Cesar-Ranchería Basin of La Guajira and Cesar. The formation consists of bituminous coal fie ...
of La Guajira
La Guajira () is a department of Colombia. It occupies most of the Guajira Peninsula in the northeast region of the country, on the Caribbean Sea and bordering Venezuela, at the northernmost tip of South America. The capital city of the departm ...
.[
]
Outcrops
The Bogotá Formation is apart from its type locality, found in the synclinals of the Río Frío, Checua
Checua is a Andean preceramic, preceramic open area List of Muisca and pre-Muisca sites, archaeological site in Nemocón, Cundinamarca Department, Cundinamarca, Colombia. The site is located north of the town centre.Gómez Mejía, 2012, p.146 At ...
-Lenguazaque
Lenguazaque is a municipality and town of Colombia in the Departments of Colombia, department of Cundinamarca Department, Cundinamarca. Lenguazaque is situated on the Altiplano Cundiboyacense, part of the Cordillera Oriental (Colombia), Eastern Ran ...
, Sesquilé
Sesquilé is a town and municipality in Almeidas Province in the department of Cundinamarca, Colombia. Sesquilé in the Chibcha language of the Muisca means "hot water". , Sisga, Subachoque
Subachoque is a municipality and town of Colombia in the Western Savanna Province, part of the department of Cundinamarca. The municipality is situated on the Bogotá savanna with the urban centre at an altitude of at a distance of from the c ...
,[Plancha 227, 1998] around Lake Suesca
Lake Suesca is a natural water body situated on the Altiplano Cundiboyacense, belonging to the municipalities of Suesca and Cucunubá in the department of Cundinamarca, Colombia. The basin has a semi-elliptical shape that extends on a north–s ...
, in the Tenza Valley
The Tenza Valley (Spanish: ''Valle de Tenza'') is an intermontane valley in the Eastern Ranges of the Colombian Andes. The valley stretches over the southeastern part of the department of Boyacá and the northeastern part of Cundinamarca. It ...
, and in the synclinals of Teusacá and Usme
Usme is the 5th locality of the Capital District of Bogotá, capital city of Colombia. Usme is located in the south of Bogotá, bordering to the north the localities of San Cristóbal, Rafael Uribe Uribe and Tunjuelito, to the west the locali ...
.[Plancha 246, 1998][Geological Map Bogotá, 1997] In the Usme Synclinal, the formation has a thickness of .[Bayona et al., 2010, p.10] The campus of the Universidad La Javeriana has the Bogotá Formation as solid basement rock.[García & Alfaro, 2001, p.5]
The Bogotá Formation forms the footwall
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
of the eastward compressional Chicamocha Fault,[ and the footwall of the westward ]thrusting
Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that sys ...
Bogotá Fault.[
]
Regional correlations
Itaboraian correlations
See also
* Geology of the Eastern Hills
* Geology of the Ocetá Páramo
* Geology of the Altiplano Cundiboyacense
Notes and references
Notes
References
Bibliography
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Maps
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External links
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{{DEFAULTSORT:Bogota Formation
Geologic formations of Colombia
Paleogene Colombia
Paleocene Series of South America
Eocene Series of South America
Casamayoran
Riochican
Itaboraian
Peligran
Selandian Stage
Thanetian Stage
Ypresian Stage
Fossiliferous stratigraphic units of South America
Paleontology in Colombia
Mudstone formations
Siltstone formations
Sandstone formations
Shale formations
Formations
Formations
Formations