The Middle Magdalena Valley, Middle Magdalena Basin or Middle Magdalena Valley Basin ( es, Valle Medio del Magdalena, commonly abbreviated to VMM) is an

intermontane basin Intermontane is a physiographic adjective formed from the prefix " inter-" (''signifying among, between, amid, during, within, mutual, reciprocal'') and the adjective "montane" (inhabiting, or growing in mountainous regions, especially cool, moi ...

, located in north-central Colombia between the

Central Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known a ...

and

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 Le ...

of the

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 basin, covering an area of , is situated in the

departments Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military *Department (administrative division), a geographical and administrative division within a country, ...

Santander Santander may refer to: Places * Santander, Spain, a port city and capital of the autonomous community of Cantabria, Spain * Santander Department, a department of Colombia * Santander State, former state of Colombia * Santander de Quilichao, a ...

, Boyacá, Cundinamarca and Tolima. The basin is structurally bounded by the

Palestina Fault The Palestina Fault ( es, Falla de Palestina) is a regional sinistral oblique thrust fault in the departments of Antioquia, Caldas Department, Caldas and Bolívar Department, Bolívar in central Colombia. The fault has a total length of and runs a ...

to the west and the Bucaramanga Fault to the east. The Middle Magdalena Valley hosts the middle course of the

Magdalena River The Magdalena River ( es, Río Magdalena, ; less commonly ) is the main river of Colombia, flowing northward about through the western half of the country. It takes its name from the biblical figure Mary Magdalene. It is navigable through much o ...

, the main river of Colombia, flowing from the

Upper Magdalena Valley 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 fo ...

in the south to the

Lower Magdalena Valley Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Gloucestershire, England See also *Nizhny Nizhny (russian: Ни́жний; masculine), Nizhnyaya (; feminine), or Nizhneye (russian: Ни́� ...

to the northwest. The basin is elongated with an approximate width of and extends to the north for approximately , where it terminates against the Santander Massif and Cesar Valley. To the south, it terminates against the Upper Magdalena Valley, which consists of the Girardot and Neiva Sub-basins where the Central and Eastern Ranges converge. The basin is an important producer of oil in Colombia, with main fields Yariguí-Cantagallo,

Moriche ''Mauritia flexuosa'', known as the moriche palm, ''ité'' palm, ''ita'', ''buriti'', ''muriti'', ''miriti'' (Brazil), ''canangucho'' (Colombia), ''acho'' (Ecuador), or ''aguaje'' (Peru), is a palm tree. It grows in and near swamps and other wet ...

Casabe Tapioca (; ) is a starch extracted from the storage roots of the cassava plant (''Manihot esculenta,'' also known as manioc), a species native to the North and Northeast regions of Brazil, but whose use is now spread throughout South America. ...

, La Cira-Infantas, Velásquez,

Santos Santos may refer to: People *Santos (surname) *Santos (DJ) (born 1971), Italian DJ *Santos Benavides (1823–1891), Confederate general in the American Civil War *Santos Balmori Picazo (1899–1992), Spanish-Mexican painter * Santos (footballer, ...

, Palagua, Teca, Payoa and Lisama. The first three fields were among the twenty most producing fields of Colombia in 2016.En 20 campos se produce el 66 % del petróleo del país
/ref> Until 2008, La Cira-Infantas and Casabe produced more than and respectively.Garcia González et al., 2009, p.185 Main producing

reservoirs A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including control ...

are the Colorado, Mugrosa, Esmeraldas and La Paz Formations. Secondary reservoirs are Lisama and La Luna.Garcia González et al., 2009, p.80

Etymology

The name of the basin is taken from the middle course of the

Basin development

During the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

period,

Pangea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million ...

began to pull apart causing separation of North America from South America. This

rifting In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-grabe ...

produced a

subduction zone Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

where the

Nazca Plate The Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the ...

was subducting to the east under the

South American Plate The South American Plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African Plate, with which it forms the southern part of the Mi ...

. Part of this subducting plate was the Baudo-Island Arc separated from the South American continent by the marginal Colombian Sea. The formation of the extensional

back-arc A back-arc basin is a type of geologic basin, found at some convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found in the western Pacific Ocean. Most of ...

basin associated with this

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

is the origin of the Middle Magdalena Basin in the late

. Throughout the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

, the basin experienced thermal subsidence and five transgressive-regressive cycles as part of a marine megacycle. In the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

, the rate of

increased causing the marginal Colombian Sea to close and the Baudo-Island Arc to collide with the South American continent. This caused

accretion Accretion may refer to: Science * Accretion (astrophysics), the formation of planets and other bodies by collection of material through gravity * Accretion (meteorology), the process by which water vapor in clouds forms water droplets around nuc ...

of the Western Ranges and uplift of the

Central Ranges Central Ranges (code CER) is an Australian bioregion, with an area of 101,640.44 square kilometres (39,244 sq mi) spreading across two states and one territory: South Australia, Western Australia, and the Northern Territory.back-arc A back-arc basin is a type of geologic basin, found at some convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found in the western Pacific Ocean. Most of ...

basin into the pre-Andean

foreland basin A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithosphere ...

. Around the time of the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but ...

, the

Nazca plate The Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the ...

increased its

to the east while the

South American plate The South American Plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African Plate, with which it forms the southern part of the Mi ...

experienced a westward pull. This caused the

Andean orogeny The Andean orogeny ( es, Orogenia andina) is an ongoing process of orogeny that began in the Early Jurassic and is responsible for the rise of the Andes mountains. The orogeny is driven by a reactivation of a long-lived subduction system along ...

in the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

and uplift of the

in the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58intermontane Intermontane is a physiographic adjective wiktionary:compound#Adjective, formed from the prefix "wiktionary:inter-, inter-" (''signifying among, between, amid, during, within, mutual, reciprocal'') and the adjective "wiktionary:montane#Adjective, ...

basin situated between the uplifted Central and Eastern Ranges.

Geologic structures

Faulting in the Middle Magdalena Basin is primarily reverse and thrust faulting. Reverse faulting is high angle in the west and low angle in the eastern and central areas of the basin with normal faults also developing along the eastern margin. These

thrust faults A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If ...

formed from thrusting from the eastern margin of the

Central Ranges Central Ranges (code CER) is an Australian bioregion, with an area of 101,640.44 square kilometres (39,244 sq mi) spreading across two states and one territory: South Australia, Western Australia, and the Northern Territory.Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

and the western margin of the

in the

. The major

in the Middle Magdalena Basin include the Infantas Thrust, La Salina Thrust, and Cantagallo Thrust. The basin is structurally bounded by the

, a dextral strike-slip fault system, in the west and the

Bucaramanga-Santa Marta Fault The Bucaramanga-Santa Marta Fault (BSMF, BSF) or Bucaramanga-Santa Marta Fault System ( es, (Sistema de) Falla(s) de Bucaramanga-Santa Marta) is a major oblique transpressional sinistral strike-slip fault (wrench fault) in the departments of Magda ...

, a sinistral strike-slip system, in the east. The major surface structures of the Middle Magdalena Basin are asymmetric

syncline In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed ...

s and basement cored

anticline In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...

s, which formed as a result of thrusting from the

Eastern Eastern may refer to: Transportation *China Eastern Airlines, a current Chinese airline based in Shanghai *Eastern Air, former name of Zambia Skyways *Eastern Air Lines, a defunct American airline that operated from 1926 to 1991 * Eastern Air L ...

and

Central Ranges Central Ranges (code CER) is an Australian bioregion, with an area of 101,640.44 square kilometres (39,244 sq mi) spreading across two states and one territory: South Australia, Western Australia, and the Northern Territory.syncline In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed ...

against the

hanging wall 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 fault next to an inclined

. Key folds in the basin for hydrocarbon exploration include the Nuevo Mundo and Guaduas Synclines. As suggested by the formation of the folds, both of these synclines are bounded by thrust faulting and anticlines.

Stratigraphy

The stratigraphy of the Middle Magdalena Basin can be divided into three sequences separated by angular unconformities. The basement of these sequences is Pre-Mesozoic metaclastics and sediments which are now exposed on the surface of the Central Cordillera as a result of its deformation and uplift. This geologic basement is at most deep, with faulted sections shifted up to approximately in depth. The

unconformity An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval o ...

that separates the basement from the first sequences indicates the approximate time

began.

First sequence

The first sequence was deposited in the

during the

which caused the initial formation of the basin. This

formation is called the

Girón Formation The Girón Formation ( es, Formación Girón, Jg) is an extensive geological formation stretching across from the north in Teorama, Norte de Santander, across the Mesa de Los Santos and Chicamocha Canyon towards west of Nobsa, Boyacá in the nor ...

which consists of siltstones and rhyolitic tuffs. During this period, the basin also experienced granitic plutonism along its western margins. The

angular unconformity, separating the first and second sequence, is representative of the post-rift boundary.

Second sequence

The middle sequence represents the formations deposited throughout the

and

Early Paleocene The Danian is the oldest age or lowest stage of the Paleocene Epoch or Series, of the Paleogene Period or System, and of the Cenozoic Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian) is at the Cret ...

. The oldest formations in this sequence are the

Tambor Tambor can refer to: * Tambor, Costa Rica, a town in Costa Rica ** Tambor Airport, an airport that serves Tambor, Costa Rica * El Tambor River, river in Guatemala * Jeffrey Tambor (born 1944), American actor * Tambor (dance), Afro-Venezuelan mus ...

and

Los Santos Formation LOS, or Los, or LoS may refer to: Science and technology * Length of stay, the duration of a single episode of hospitalisation * Level of service (transportation), Level of service, a measure used by traffic engineers * Level of significance, a ...

s. The conglomerates and sandstones indicate a continental to fluvial

depositional environment In geology, depositional environment or sedimentary environment describes the combination of physical, chemical, and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will b ...

. In the

Early Cretaceous The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pr ...

, sea level began to rise and formed a shallow marine environment with siltstone and shale deposits of the

Cumbre Formation ''Cumbre'' is a genus of skippers in the family Hesperiidae Skippers are a family of the Lepidoptera (moths and butterflies) named the Hesperiidae. Being diurnal, they are generally called butterflies. They were previously placed in a separ ...

. Sea level continued to rise throughout the

Middle Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

when the Tablazo and Salto limestones and Simití shales were deposited. The

La Luna Formation LA most frequently refers to Los Angeles, the second largest city in the United States. La, LA, or L.A. may also refer to: Arts and entertainment Music * La (musical note), or A, the sixth note * "L.A.", a song by Elliott Smith on ''Figure ...

represents a

maximum flooding surface In sequence stratigraphy, a maximum flooding surface is the surface that marks the transition from a transgression to a regression. Maximum flooding surfaces are abbreviated by mfs, synonyms for them include final transgressive surface, surface of ...

with deep marine deposits of limestone, chert, and shale. Sea level then began to fall, returning the environment to shallow marine with deposition of the Umir Formation of shales and sandstones. Finally, the

saw the deposition of the Lisama Formation, consisting of deltaic mudstones and sandstones. This entire middle sequence indicates a marine megacycle consisting of five transgressive-regressive cycles. The angular unconformity between the second and third sequences is a result of erosion from the accretion of the Western Ranges.

Third sequence

The final sequence represents deposition from the

Early Tertiary 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 ...

to present day. Within this sequence, there are three subsequences that are the result of deformation and uplift of the Central and Eastern Ranges. The first subsequence consists of the

Chorro Group Chorro may refer to: *El Chorro, a village in Malaga, Andalusia, Spain *El Chorro, Formosa, farm village in the Formosa province, Argentina * El Chorro, Uruguay, a resort in the Maldonado Department, Uruguay * Rancho El Chorro, a Mexican land gran ...

with the

La Paz La Paz (), officially known as Nuestra Señora de La Paz (Spanish pronunciation: ), is the seat of government of the Plurinational State of Bolivia. With an estimated 816,044 residents as of 2020, La Paz is the third-most populous city in Bo ...

and Esmeraldas Formations and the

Chuspas Group A ''chuspas'' (which is Quechua for bag) is a pouch that is used to carry coca and cocoa leaves, used primarily in the Andean region of South America. Both textiles and coca are very important to the people in Andean South America. These ''chuspa ...

with the Mugrosa and Colorado Formations, all deposited during the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

. These groups consist of fluvial sandstones, mudstones, siltstones, and shales, and are a result of erosion in the

Central Ranges Central Ranges (code CER) is an Australian bioregion, with an area of 101,640.44 square kilometres (39,244 sq mi) spreading across two states and one territory: South Australia, Western Australia, and the Northern Territory.Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

Real Group, consisting of fluvial sandstones and conglomerates. Similar to the Real Group, the final subsequence is the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Eastern 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 Le ...

uplift. The uppermost sedimentary rocks of the basin are

Pleistocene The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed ...

alluvial fan deposits, overlain by Holocene sediments of the Magdalena River.

Petroleum resources

The primary reservoirs in the Middle Magdalena Basin are fluvial sandstones and conglomerates from the Churro and Chuspas Groups, which have 20 to 25%

porosity Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...

and 0.5 to 1 D permeability. The main source of

hydrocarbons In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...

is the La Luna limestone, with a

Total Organic Carbon Total organic carbon (TOC) is the amount of carbon found in an organic compound and is often used as a non-specific indicator of water quality or cleanliness of pharmaceutical manufacturing equipment. TOC may also refer to the amount of organic c ...

(TOC) content of 3 to 4% and Type II marine

kerogen Kerogen is solid, insoluble organic matter in sedimentary rocks. Comprising an estimated 1016 tons of carbon, it is the most abundant source of organic compounds on earth, exceeding the total organic content of living matter 10,000-fold. It ...

, sealed by overlying

shales. There are three types of traps that house hydrocarbons in the Middle Magdalena Basin. The two structural traps are large

anticlines In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the l ...

in the center of the basin and smaller anticlines along the western margin. Both of these anticlinal traps produce from Tertiary sandstones within the Churro and Chuspas Groups. The third trap is stratigraphical with the La Luna limestone sealed by overlying shales.

Primary fields

The table above shows some of the largest producing fields. Included is their producing formation, the lithologies of the formations, and the structure of the fields containing the

. The Tune and Avechucos Formations are equivalent to the Chorro and Chuspas Groups. Both the Casabe and Yariguí-Cantagallo Fields are located on the

towards the western margin of the basin with the Yariguí-Cantagallo Field located approximately north of the

Casabe Field Tapioca (; ) is a starch extracted from the storage roots of the cassava plant (''Manihot esculenta,'' also known as manioc), a species native to the North and Northeast regions of Brazil, but whose use is now spread throughout South America. ...

. Approximately east of the Casabe Field is the oldest and largest

La Cira-Infantas Field LA most frequently refers to Los Angeles, the second largest city in the United States. La, LA, or L.A. may also refer to: Arts and entertainment Music * La (musical note), or A, the sixth note * "L.A.", a song by Elliott Smith on ''Figur ...

, situated towards the central to eastern margin of the basin. The Velásquez Field is located at the southern end of the basin near the Upper Magdalena Valley. Current exploration is focused in the southern area of the basin, where heavy amounts of faulting could house potential

. Aside from the La Luna limestone, other potential

source rock In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been deposi ...

s include

sediments such as the

Paja Paja may refer to: * Paja, Iran, a village in Sari County * Paja (given name), a Serbian masculine name * Paja (surname) * Paja Formation, geologic formation in Colombia * Paja Brava :''Paja Brava is also used in Spanish speaking countries to re ...

and

Simití Formation Simiti is a town and municipality located in the Bolívar Department, northern Colombia. History Simití was founded in 1537 by Antonio de Lebrija and Juan Maldonado, two soldiers of the expedition from Santa Marta to the Muisca Confederati ...

s, or the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

shales of the

Umir Formation In Norse mythology, Ymir (, ), also called Aurgelmir, Brimir, or Bláinn, is the ancestor of all jötnar. Ymir is attested in the '' Poetic Edda'', compiled in the 13th century from earlier traditional material, in the '' Prose Edda'', wr ...

Regional correlations

Gallery

File:Petroleum regions - south america map-es.svg, VMM, major in South America File:Colombia Pipelines map-fr.svg, Pipelines in Colombia File:Alto Magdalena Pipeline physical map-fr.svg, Alto Magdalena pipeline File:Caño Limón-Coveñas Pipeline physical map-fr.svg, Caño Limón-Coveñas pipeline File:Colombia Pipeline physical map-fr.svg, Colombia pipeline File:Ocensa Pipeline physical map-fr.svg, Ocensa pipeline File:Escudo de Barrancabermeja.svg, Barrancabermeja File:Escudo de la Diócesis de Barrancabermeja.svg, Barrancabermeja File:Coat of arms of Santander Department.svg, Santander File:Escudo de San Miguel-La Dorada.svg, La Dorada File:Escudo de Puerto Boyacá.svg, Puerto Boyacá File:Escudo de Puerto Triunfo.svg, Puerto Triunfo File:Escudo de Pulí.svg, Pulí

References

Bibliography

* *

Etymology

Basin development

Geologic structures

Stratigraphy

First sequence

Second sequence

Third sequence

Petroleum resources

Primary fields

Regional correlations

Gallery

See also

References

Bibliography

Further reading

Basin classifications

Colombia general

Middle Magdalena Valley

Maps