The Cacho Formation ( es, Formación Cacho, E1C, Tpc, Tec) 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
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 ...
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
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 ...
The formation was first described by Hubach in 1931 and 1957 and named by Campbell in 1962 and Julivert in 1963.Montoya & Reyes, 2005, p.55Acosta & Ulloa, 2002, p.58
Description
Lithologies
The Cacho Formation consists of white, yellow and reddish fine to coarse cross-bedded
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 ...
s in thick banks intercalated with reddish and grey shales.
Stratigraphy and depositional environment
The thick Cacho Formation overlies the
Guaduas Formation
The Guaduas Formation ( es, Formación Guaduas, K2P1G, K2E1G, KPgg, KTg, TKg, Ktg) is a geological formation of the Middle Magdalena Basin and the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly shale with coa ...
and is overlain by the
Bogotá Formation
The Bogotá Formation ( es, Formación Bogotá, E1-2b, 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 form ...
.Guerrero Uscátegui, 1992, p.5 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 ...
, based on paleoflora studied by
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.Lower Socha and Barco Formations.Montoya & Reyes, 2005, p.57
Outcrops
The Cacho Formation is apart from its type locality in
, found in the Eastern Hills of Bogotá, and many other locations in the Eastern Ranges up until the south of Boyacá. 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".
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 ...
Guatavita
Guatavita is a municipality and town of Colombia in the Guavio Province of the department of Cundinamarca. Guatavita is located 75 km northeast of the capital Bogotá. It borders Sesquilé and Machetá in the north, Gachetá and Junín in ...