The Simijaca Formation ( es, Formación Simijaca, K₂S, Kss) 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 Altiplano Cundiboyacense, Eastern Ranges 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 Car ...

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

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. ...

formation dates to 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'', the ...

period;

Turonian The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by t ...

and

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

epochs, and has a maximum thickness of .

Etymology

The formation was defined and named in 1991 by Ulloa and Rodríguez after

Simijaca Simijaca () is a town and municipality in the Ubaté Province, part of the Cundinamarca Department, Colombia. The town centre is located at an altitude of on the Altiplano Cundiboyacense at from the capital Bogotá. Simijaca borders the Boyacá D ...

, Cundinamarca.Montoya & Reyes, 2005, p.21

Description

Lithologies

The Simijaca Formation is characterised by a sequence of

s, grey and black

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, especial ...

s 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 silicates) ...

and

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

intercalations.

Stratigraphy and depositional environment

The Simijaca Formation conformably overlies the

Chiquinquirá Sandstone Chiquinquirá is a town and municipality in the Colombian Department of Boyacá, part of the subregion of the Western Boyacá Province. Located some 115 km north of Bogotá, Chiquinquirá is above sea level and has a yearly average temp ...

, and the Hiló and

Pacho Formation The Pacho Formation ( es, Limolitas de Pacho, Kslp) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consisting of alternating siltstones and shales with siderite concretions dates to t ...

s, and is overlain by the

La Frontera Formation The La Frontera Formation ( es, Formación La Frontera, K2F, Ksf) is a geological formation, part of the Villeta Group, of the Altiplano Cundiboyacense and neighbouring areas of the Eastern Ranges of the Colombian Andes. The sequence of limestones ...

.Acosta & Ulloa, 2001, p.32 The age has been estimated to be

, or

.Acosta & Ulloa, 2001, p.41 Stratigraphically, the formation is time equivalent with the

Chipaque Formation The Chipaque Formation ( es, Formación Chipaque, K2cp, Kc) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation is also described as Gachetá Formation, named after Gachetá, in the area o ...

.Montoya & Reyes, 2005, p.22 The formation has been deposited in an

open marine Open or OPEN may refer to: Music * Open (band), Australian pop/rock band * The Open (band), English indie rock band * ''Open'' (Blues Image album), 1969 * ''Open'' (Gotthard album), 1999 * ''Open'' (Cowboy Junkies album), 2001 * ''Open'' (YF ...

platform setting.García González et al., 2009, p.209 The deposition is represented by a

maximum flooding surface In sequence stratigraphy Sequence stratigraphy is a branch of geology, specifically a branch of stratigraphy, that attempts to discern and understand historic geology through time by subdividing and linking sedimentary deposits into unconformity bo ...

.Villamil, 2012, p.164

Outcrops

The Simijaca Formation is apart from its type locality in the Quebrada Don Lope,Acosta & Ulloa, 2001, p.38 found at surface in the north of the Bogotá savanna, in the Tabio anticlinal, along the road

Ubaté Ubaté (originally Villa San Diego de Ubaté) is a town and municipality in the Ubaté Province, part of Cundinamarca Department, Colombia. Ubaté is the capital of the province with the same name and situated in the Ubaté–Chiquinquirá Vall ...

Carmen de Carupa Carmen de Carupa is a municipality and town of Colombia in the Ubaté Province, part of the department of Cundinamarca. The municipality, located in the Ubaté-Chiquinquirá Valley on the Altiplano Cundiboyacense borders San Cayetano in the ...

,Montoya & Reyes, 2005, p.23 at the western and eastern flanks of the Aponsentos-Chiquinquirá Synclinal,Plancha 190, 2009 near

Tena TENA is a Sweden, Swedish-based brand of Essity that specializes in products for adults with urinary incontinence, urinary or fecal incontinence, such as pads and diapers. TENA also produces a youth diaper brand for teenagers and larger childre ...

, south of

Anolaima Anolaima () is a municipality and township of Colombia in the department of Cundinamarca. It is located in the providence of Tequendama at West from Bogotá in between the cities of Facatativá and La Mesa. Anolaima is known as the Fruit Capit ...

and

Cachipay Cachipay is a municipality and town of Colombia in the Tequendama Province, part of the department of Cundinamarca. Cachipay borders Quipile in the west, Zipacón in the east, Anolaima in the north and La Mesa in the south. The urban centre is ...

,Plancha 227, 1998 and between

Anapoima Anapoima () is a Colombian municipality in the department of Cundinamarca located from Bogotá. History The first inhabitants of the region were the Anapoymas Indians of the Panche nation. Between Tocaima and Tena there existed only small in ...

and

Granada Granada (,, DIN 31635, DIN: ; grc, Ἐλιβύργη, Elibýrgē; la, Illiberis or . ) is the capital city of the province of Granada, in the autonomous communities of Spain, autonomous community of Andalusia, Spain. Granada is located at the fo ...

.Plancha 246, 1998

Regional correlations

References

Bibliography

* * * *

Maps

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External links

* {{cite LSA , last=Gómez , first=J. , last2=Montes , first2=N.E. , last3=Nivia , first3=Á. , last4=Diederix , first4=H. , year=2015 , title=Plancha 5-09 del Atlas Geológico de Colombia 2015 – escala 1:500,000 , url=https://www.researchgate.net/publication/309533589_Plancha_5-09_del_Atlas_Geologico_de_Colombia_2015 , publisher=

Servicio Geológico Colombiano The Colombian Geological Survey (CGS) ( es, Servicio Geológico Colombiano; formerly known as INGEOMINAS) is a scientific agency of the Colombian government in charge of contributing to the socioeconomic development of the nation through research ...

, pages=1 , accessdate=2017-03-23 Geologic formations of Colombia Cretaceous Colombia Upper Cretaceous Series of South America Cenomanian Stage Turonian Stage Mudstone formations Shale formations Limestone formations Open marine deposits Formations Geography of Cundinamarca Department Geography of Boyacá Department