The Otú Norte or Otú-Pericos Fault () is an inactive sinistral

oblique Oblique may refer to: * an alternative name for the character usually called a slash (punctuation) ( / ) *Oblique angle, in geometry * Oblique triangle, in geometry * Oblique lattice, in geometry * Oblique leaf base, a characteristic shape of the ...

strike-slip fault 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 ...

in the department of

Antioquia Antioquia is the Spanish form of Antioch. Antioquia may also refer to: * Antioquia Department Antioquia () is one of the 32 departments of Colombia, located in the central northwestern part of Colombia with a narrow section that borders th ...

in northern

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

. The fault has a total length of and runs along an average north-northwest to south-southeast

strike Strike may refer to: People *Strike (surname) * Hobart Huson, author of several drug related books Physical confrontation or removal *Strike (attack), attack with an inanimate object or a part of the human body intended to cause harm * Airstrike, ...

of 346.4 ± 8, cross-cutting the northern part 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.Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

. Together with the parallel

Bagre Norte Fault The Bagre Norte Fault () is a sinistral oblique strike-slip fault in the departments of Antioquia and Bolívar in northern Colombia. The fault has a total length of and runs along an average north to south strike of 359 ± 14 along the Central R ...

the fault separates the Central Ranges from its northeasternmost continuation, the

Serranía de San Lucas The Serranía de San Lucas is a forested massif in the Bolívar Department of northern Colombia that reaches heights of 2,600 m above sea level. It is part of the Magdalena–Urabá moist forests ecoregion, with a rainforest ecology that include ...

Etymology

The fault was by Feininger et al. in 1972 named after

Otú Airport Otú Airport () is an airport located in the village of Otú and serving the town of Remedios, a municipality of the Antioquia Department in Colombia. It is also known as Alberto Jaramillo Sanchez Airport. Currently only Aerolínea de Antioqui ...

in vereda Otú in Remedios,

.Consorcio GSG, 2015, p.168

Description

The Otú Norte Fault crosses the northern part of the

. The fault strikes north-northwest to south-southeast and appears to branch off the

Palestina Fault The Palestina Fault () is a regional sinistral oblique thrust fault in the departments of Antioquia, Caldas and Bolívar in central Colombia. The fault has a total length of and runs along an average north-northeast to south-southwest strike of ...

. The Otú Fault extends in a northwest direction to near

Nechí Nechi is a town and municipality in the Colombian department of Antioquia. The population was 24,066 at the 2018 census. Climate Nechí has a tropical rainforest climate A tropical rainforest climate or equatorial climate is a tropical climate ...

, where it is covered by young

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

deposits. The sinistral

reverse fault 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 f ...

separates blocks of totally dissimilar geology and lithology; the

metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...

Precambrian The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of t ...

San Lucas Complex and

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 143.1 Mya. ...

igneous rocks (

diorite Diorite ( ) is an intrusive rock, intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals. It is Intermediate composition, inter ...

s) of the Segovia Batholith on the east are juxtaposed against the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

Santa Isabel Stock Santa Claus (also known as Saint Nicholas, Saint Nick, Father Christmas, Kris Kringle or Santa) is a legendary figure originating in Western Christian culture who is said to bring gifts during the late evening and overnight hours on Christma ...

and Paleozoic

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

feldspar Feldspar ( ; sometimes spelled felspar) is a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagiocl ...

gneiss Gneiss (pronounced ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. This rock is formed under p ...

es and

quartzitic Quartzite is a hard, non-Foliation (geology), foliated metamorphic rock that was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usuall ...

arc rocks of the Cajamarca Complex on the west.Fonseca et al., 2011, p.40Fonseca et al., 2011, p.64 Just west of Remedios, the fault forms the contact between the Cretaceous

and Jurassic Segovia Batholiths.Geological Map of Antioquia, 1999 The northern end apparently splays into several faults that cross the Nechí River.Paris et al., 2000, p.28

Activity

A rate of less than per year is estimated for the fault, considered inactive. Displaced Quaternary terraces as high as are reported and the fault offsets the Tertiary erosion surface of the Central Ranges.Paris et al., 2000, p.29 A total displacement of the fault has been estimated at .Álvarez et al., 2007, p.49

Economic importance

The fault separates two major

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

mining areas in Antioquia; the Segovia-Remedios mining district and La Ye mine in the east,Segovia-Remedios mining district
/ref>Mining Atlas - La Ye
/ref> and the

placer deposit In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. The name is from the Spanish language, Spanish word ''placer'', meaning "alluviu ...

s of Gramalote and Cisneros in the west.Mining Atlas - Gramalote
/ref>Mining Technology - Cisneros
/ref> North of

Zaragoza Zaragoza (), traditionally known in English as Saragossa ( ), is the capital city of the province of Zaragoza and of the autonomous communities of Spain, autonomous community of Aragon, Spain. It lies by the Ebro river and its tributaries, the ...

, the fault underlies the El Limón mine.Mining Atlas - El Limón
/ref> Antioquia produces 50% of all gold in Colombia.Fonseca et al., 2011, p.126 The ductile zone of the fault produced

mylonite Mylonite is a fine-grained, compact metamorphic rock produced by dynamic recrystallization of the constituent minerals resulting in a reduction of the grain size of the rock. Mylonites can have many different mineralogical compositions; it is a ...

s in mainly the

amphibolite Amphibolite () is a metamorphic rock that contains amphibole, especially hornblende and actinolite, as well as plagioclase feldspar, but with little or no quartz. It is typically dark-colored and dense, with a weakly foliated or schistose ...

facies of the Segovia Batholith.Álvarez et al., 2007, p.47 This ductile behavior was later overprinted by fragile tectonics, leaving cataclasis and fault breccias in the fault zone as well as striations in the quartz of the

batholith A batholith () is a large mass of intrusive rock, intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in the Earth's crust. Batholiths are almost always made mostly of felsic or intermediate ...

. These deformations are interpreted as second grade Riedel shears.Álvarez et al., 2007, p.48

Etymology

Description

Activity

Economic importance

See also

References

Bibliography

Maps

Further reading