The
Bogotá Formation (
Spanish :
Formación Bogotá , E
1-2 b, Tpb, Pgb) is a
geological formation of the
Eastern Hills and
Bogotá savanna on the
Altiplano Cundiboyacense ,
Eastern Ranges of the
Colombian Andes . The predominantly
shale and
siltstone formation, with
sandstone beds intercalated, dates to the
Paleogene period;
Upper Paleocene to
Lower Eocene epochs, with an age range of 61.66 to 52.5 Ma, spanning the
Paleocene–Eocene Thermal Maximum . The thickness of the Bogotá Formation ranges from 169 metres (554 ft) near
Tunja to 1,415 metres (4,642 ft) near Bogotá. Fossils of the
ungulate 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, then by Hubach in 1931, 1945 and 1957, and named in 1963 by Julivert after the Colombian capital Bogotá and its savanna .
Description
The Bogotá Formation was deposited during the Paleocene–Eocene Thermal Maximum , here indicated as LPTM
Lithologies
The Bogotá Formation consists mainly of grayish-red, locally purplish, commonly greenish-gray, generally poorly stratified mudstone and silty claystone . Lithic arenite sandstone lenses, ranging from fine- to medium-grained, generally friable and variegated, are local constituents. Carbonaceous material is present as thin beds of low-grade argillaceous coal , north of Bogotá. Fossil remains of Etaoya bacatensis , named after Colombian geologist Fernando Etayo and the indigenous name for the Bogotá savanna, Bacatá , have been found in Ciudad Bolívar , close to the type locality of the Bogotá Formation. Additionally, macroflora of Palaeophytocrene hammenii , named after Dutch botanist Thomas van der Hammen , and pollen 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. The abundant paleosols of the Bogotá Formation show an increase in chemical weathering across the Paleocene-Eocene (P-E) transition; the Paleocene–Eocene Thermal Maximum .
Later analysis has found several other species, such as pleurodire turtles, found at the Doña Juana dump, dyrosaurid mesoeucrocodylians, boid snakes, dipnoan fishes, frogs, lizards, sebecid crocodyliforms and 11 fossils of mammals. The find of a derived snake in the Lower Eocene section of the formation represents the oldest New World record. 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). The faunal distribution has been correlated to the Carodnia -, Amphidolops -, and Wainka -bearing Peñas Coloradas Formation of the Golfo San Jorge Basin in Patagonia , Argentina .
Stratigraphy and depositional environment
The Bogotá Formation, with a thickness of 169 metres (554 ft) close to Tunja to 1,415 metres (4,642 ft) near Bogotá, overlies the Cacho Formation and is overlain by the Regadera Formation . The age has been estimated to be Late Paleocene to Early Eocene . The middle part of the succession has been dated using detrital zircons at 56.2 ± 1.6 Ma. The spread of ages based on zircons has been reported from 60.96 ± 0.7 to 53.6 ± 1.1 Ma. The Bogotá Formation is laterally equivalent with the shales of the Socha Formation , the San Fernando Formation , the El Limbo Formation , Los Cuervos Formation , and the fossil-rich Cerrejón Formation of La Guajira .
Outcrops
The Bogotá Formation is apart from its type locality , found in the synclinals of the Río Frío , Checua -Lenguazaque , Sesquilé , Sisga , Subachoque , around Lake Suesca , in the Tenza Valley , and in the synclinals of Teusacá and Usme . In the Usme Synclinal, the formation has a thickness of 436.5 metres (1,432 ft). The campus of the Universidad La Javeriana has the Bogotá Formation as solid basement rock.
The Bogotá Formation forms the footwall of the eastward compressional Chicamocha Fault, and the footwall of the westward thrusting Bogotá Fault .
Regional correlations
Stratigraphy of the Llanos Basin and surrounding provinces
Ma
Age
Paleomap
Regional events
Catatumbo
Cordillera
proximal Llanos
distal Llanos
Putumayo
VSM
Environments
Maximum thickness
Petroleum geology
Notes
0.01
Holocene
Holocene volcanismSeismic activity
alluvium
Overburden
1
Pleistocene
Pleistocene volcanismAndean orogeny 3Glaciations
Guayabo
Soatá Sabana
Necesidad
Guayabo
Gigante
Alluvial to fluvial (Guayabo)
550 m (1,800 ft) (Guayabo)
2.6
Pliocene
Pliocene volcanism Andean orogeny 3GABI
Subachoque
5.3
Messinian
Andean orogeny 3Foreland
Marichuela
Caimán
Honda
13.5
Langhian
Regional flooding
León
hiatus
Caja
León
Lacustrine (León)
400 m (1,300 ft) (León)
Seal
16.2
Burdigalian
Miocene inundationsAndean orogeny 2
C1
Carbonera C1
Ospina
Proximal fluvio-deltaic (C1)
850 m (2,790 ft) (Carbonera)
Reservoir
17.3
C2
Carbonera C2
Distal lacustrine-deltaic (C2)
Seal
19
C3
Carbonera C3
Proximal fluvio-deltaic (C3)
Reservoir
21
Early Miocene
Pebas wetlands
C4
Carbonera C4
Barzalosa
Distal fluvio-deltaic (C4)
Seal
23
Late Oligocene
Andean orogeny 1Foredeep
C5
Carbonera C5
Orito
Proximal fluvio-deltaic (C5)
Reservoir
25
C6
Carbonera C6
Distal fluvio-lacustrine (C6)
Seal
28
Early Oligocene
C7
C7
Pepino
Gualanday
Proximal deltaic-marine (C7)
Reservoir
32
Oligo-Eocene
C8
Usme
C8
onlap
Marine-deltaic (C8)
Seal Source
35
Late Eocene
Mirador
Mirador
Coastal (Mirador)
240 m (790 ft) (Mirador)
Reservoir
40
Middle Eocene
Regadera
hiatus
45
50
Early Eocene
Socha
Los Cuervos
Deltaic (Los Cuervos)
260 m (850 ft) (Los Cuervos)
Seal Source
55
Late Paleocene
PETM 2000 ppm CO2
Los Cuervos
Bogotá
Gualanday
60
Early Paleocene
SALMA
Barco
Guaduas
Barco
Rumiyaco
Fluvial (Barco)
225 m (738 ft) (Barco)
Reservoir
65
Maastrichtian
KT extinction
Catatumbo
Guadalupe
Monserrate
Deltaic-fluvial (Guadalupe)
750 m (2,460 ft) (Guadalupe)
Reservoir
72
Campanian
End of rifting
Colón-Mito Juan
83
Santonian
Villeta /Güagüaquí
86
Coniacian
89
Turonian
Cenomanian-Turonian anoxic event
La Luna
Chipaque
Gachetá
hiatus
Restricted marine (all)
500 m (1,600 ft) (Gachetá)
Source
93
Cenomanian
Rift 2
100
Albian
Une
Une
Caballos
Deltaic (Une)
500 m (1,600 ft) (Une)
Reservoir
113
Aptian
Capacho
Fómeque
Motema
Yaví
Open marine (Fómeque)
800 m (2,600 ft) (Fómeque)
Source (Fóm)
125
Barremian
High biodiversity
Aguardiente
Paja
Shallow to open marine (Paja)
940 m (3,080 ft) (Paja)
Reservoir
129
Hauterivian
Rift 1
Tibú- Mercedes
Las Juntas
hiatus
Deltaic (Las Juntas)
910 m (2,990 ft) (Las Juntas)
Reservoir (LJun)
133
Valanginian
Río Negro
Cáqueza Macanal Rosablanca
Restricted marine (Macanal)
2,935 m (9,629 ft) (Macanal)
Source (Mac)
140
Berriasian
Girón
145
Tithonian
Break-up of Pangea
Jordán
Arcabuco
Buenavista
Saldaña
Alluvial , fluvial (Buenavista)
110 m (360 ft) (Buenavista)
"Jurassic"
150
Early-Mid Jurassic
Passive margin 2
La Quinta
Noreán
hiatus
Coastal tuff (La Quinta)
100 m (330 ft) (La Quinta)
201
Late Triassic
Mucuchachi
Payandé
235
Early Triassic
Pangea
hiatus
"Paleozoic"
250
Permian
300
Late Carboniferous
Famatinian orogeny
Cerro Neiva ()
340
Early Carboniferous
Fossil fish Romer's gap
Cuche (355-385)
Farallones ()
Deltaic , estuarine (Cuche)
900 m (3,000 ft) (Cuche)
360
Late Devonian
Passive margin 1
Río Cachirí (360-419)
Ambicá ()
Alluvial -fluvial -reef (Farallones)
2,400 m (7,900 ft) (Farallones)
390
Early Devonian
High biodiversity
Floresta (387-400)
Shallow marine (Floresta)
600 m (2,000 ft) (Floresta)
410
Late Silurian
Silurian mystery
425
Early Silurian
hiatus
440
Late Ordovician
Rich fauna in Bolivia
San Pedro (450-490)
Duda ()
470
Early Ordovician
First fossils
Busbanzá (>470±22 )
Guape ()
Río Nevado ()
488
Late Cambrian
Regional intrusions
Chicamocha (490-515)
Quetame ()
Ariarí ()
SJ del Guaviare (490-590)
San Isidro ()
515
Early Cambrian
Cambrian explosion
542
Ediacaran
Break-up of Rodinia
pre-Quetame
post-Parguaza
El Barro ()
Yellow: allochthonous basement (Chibcha Terrane ) Green: autochthonous basement (Río Negro-Juruena Province )
Basement
600
Neoproterozoic
Cariri Velhos orogeny
Bucaramanga (600-1400)
pre-Guaviare
800
Snowball Earth
1000
Mesoproterozoic
Sunsás orogeny
Ariarí (1000)
La Urraca (1030-1100)
1300
Rondônia-Juruá orogeny
pre-Ariarí
Parguaza (1300-1400)
Garzón (1180-1550)
1400
pre-Bucaramanga
1600
Paleoproterozoic
Maimachi (1500-1700)
pre-Garzón
1800
Tapajós orogeny
Mitú (1800)
1950
Transamazonic orogeny
pre-Mitú
2200
Columbia
2530
Archean
Carajas-Imataca orogeny
3100
Kenorland
Sources
Legend
group
important formation
fossiliferous formation
minor formation
(age in Ma)
proximal Llanos (Medina)
distal Llanos (Saltarin 1A well)
Itaboraian correlations
See also
Notes and references