Cuche Formation

Cuche Formation Stratigraphic range: Frasnian-Early Carboniferous ~385–355 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of
Underlies	Girón Fm.,
Overlies	Floresta Formation
Area	~36 km2 (14 sq mi)
Thickness	300–900 m (980–2,950 ft)
Lithology
Primary	Sandstone, siltstone
Other	Shale
Location
Coordinates	5°51′37.2″N 72°56′57.6″W / 5.860333°N 72.949333°W / 5.860333; -72.949333Coordinates: 5°51′37.2″N 72°56′57.6″W / 5.860333°N 72.949333°W / 5.860333; -72.949333
Region	Altiplano Cundiboyacense Eastern Ranges, Andes
Country	Colombia
Type section
Named for	Vereda Cuche
Named by	Botero
Location	Floresta
Year defined	1950
Coordinates	5°51′37.2″N 72°56′57.6″W / 5.860333°N 72.949333°W / 5.860333; -72.949333
Approximate paleocoordinates	51°42′S 48°06′W / 51.7°S 48.1°W / -51.7; -48.1
Region	Boyacá
Country	Colombia
Paleogeography of the Middle Devonian 380 Ma, by Stampfli & Borel

Contrasting with the original coastal depositional environment, the Cuche Formation is found at altitudes of more than 2,500 metres (8,200 ft) in the Eastern Colombian Andes around Floresta, Boyacá

The Cuche Formation (Spanish: Formación Cuche, Cc) is a geological formation of the Floresta Massif, Altiplano Cundiboyacense in the Eastern Ranges of the Colombian Andes. The sequence of siltstones, shales, and sandstone beds dates to the Late Devonian and Early Carboniferous periods, and has a maximum thickness of 900 metres (3,000 ft).

The formation was deposited in a tidal-dominated deltaic environment at high southern paleolatitudes at the edge of the Paleozoic Paleo-Tethys Ocean. The Cuche Formation is highly fossiliferous; many Placoderm fish fossils, flora, bivalves, arthropods, crustaceans and ostracods have been discovered in the youngest Paleozoic strate of the Floresta Massif, while the underlying Floresta Formation is richer in trilobite biodiversity.^[1]

Etymology[]

The formation was first described as part of the Floresta Series by Olsson and Carter in 1939. The current definition was given by Botero in 1950.^[2] The formation is named after the vereda Cuche of Floresta, Boyacá, where the formation outcrops.^[3] The word Cuche is taken from Muysccubun, the language of the indigenous Muisca, who inhabited the Altiplano Cundiboyacense before the Spanish conquest.^[4]

Regional setting[]

The Floresta Massif is a block in the northern part of the Altiplano Cundiboyacense, marked by a metamorphic crystalline core overlain by Devonian to Carboniferous sedimentary sequences; from old to young, the , Floresta and Cuche Formations. The Paleozoic succession is overlain by sediments of much younger date; the Late Jurassic Girón and Early Cretaceous . The massif is bound to the east by the and to the west by the .^[5]

At time of deposition of the Devonian formations, present-day northern South America was located at the edge of the Paleo-Tethys Ocean on the southern hemisphere. The Paleozoic occurrence on the Altiplano is localized in outcrop; the majority of surface sediments are Cretaceous to Paleogene in age. Neogene uplift of the Eastern Ranges, with its main phase in the Plio-Pleistocene, caused the exhumation of older units at surface along major thrust faults in the Eastern Andes. In two phases during the Paleozoic, intrusions occurred into the sedimentary sequence, causing local metamorphism. The first phase is considered pre-Devonian and the latter phase post-Devonian. The remaining stratigraphy of the Cuche Formation appears little affected by this intrusive phase,^[6] although slight metamorphism has been identified in later research.^[7]

Description[]

Lithologies[]

The Cuche Formation is characterised by mostly cream and purple coloured shales, with a basal unit of micaceous siltstones with intercalated yellowish-grey shales and 30 metres (98 ft) thick quartzitic and feldspar-rich sandstone beds that colour red caused by meteoric waters. The sandstones have an iron-rich cementation.^[3] A middle unit of fine-grained sandstones with thin banks of siltstones follows the lower part and an upper sequence of shales with interbedded ferruginous red beds.^[2] The lower sequence contains syn-sedimentary structures.^[3]

Stratigraphy and depositional environment[]

The depositional environment of the Cuche Formation has been analysed to be a low-energy tidal-dominated deltaic setting, with frequent marine incursions into continental and lagoonal areas marked by the presence of both the flora and the many fish species found in the formation

The Cuche Formation in some places discordantly and in other areas transitionally defined by colour changes,^[8][9] overlies the Floresta Formation in Boyacá and the in Santander,^[10] and is, by an angular unconformity up to 60 degrees,^[11] overlain by the Upper Jurassic Girón,^[12] and Early Cretaceous .^[3] The angular unconformity between the Paleozoic and Mesozoic is exposed along the road between Duitama and Sogamoso, and is the location where the first flora fossils were found in 1978.^[11]

The age of the Cuche Formation has been estimated to be Late Devonian to Early Carboniferous,^[2][13] after an original designation as Permian-Carboniferous by Botero in 1950, further restricted to the Carboniferous by Julivert in 1968.^[14] The formation covers an area of approximately 36 square kilometres (14 sq mi) and ranges in thickness between 300 and 900 metres (980 and 2,950 ft).^[2] Stratigraphically, the Cuche Formation is time equivalent with the of the Santander Massif to the north of the Altiplano Cundiboyacense.^[15] To the west of Paz de Río, the Cuche Formation is thrusted upon the Neogene by the Soapaga Fault.^[16] In the northern part of the Floresta Massif, the contact between the metamorphic and the Cuche Formation is formed by the Duga Fault.^[17]

Based on the preservation of fossils, the lithologies, syn-sedimentary structures and stratigraphic position, a depositional environment of shallow low energy waters has been proposed, possibly in a lagoonal setting at the edge of a regressional Paleo-Tethys Ocean.^[1][18] Other parts of the Cuche Formation were deposited in a continental environment, evidenced by the red beds and absence of marine fossils and abundant root imprints.^[19] Overall, the sequence represents a coastal deltaic environment with frequent marine incursions, a tidal deltaic setting.^[20][21]

Fossil content[]

Fossil flora from the Cuche Formation were identified as "Ginkgo-like" species, as this Baiera reconstruction. Proper Ginkgo do not appear in the geological record until the Middle Permian

The first identification of fossil content of the Cuche Formation was done by Botero, who studied the formation in 1950. Research in the early 1980s revealed the presence of many more fossils in the formation and among the first fossil flora found were species then identified as the genera Ginkgo and Baiera.^[14] The lower units show poorly preserved plant remains and the overlying shales provided arthropods and crustaceans. In the middle units of the formation, more and better preserved plant fossils were found alongside bivalves, ostracods (of the genus ) and arthropods.^[22]

The Cuche Formation contains unique Placoderm fish fossils, first noted by Mojica and Villarroel in 1984.^[23] Across the section, also plant fossils and bivalves are found. In this part of the sequence the first fish fossils were discovered. The top section provided brachiopods (genus Lingula) and other at that moment undetermined fossil fragments.^[24]

Later research has provided more insight into the flora of the formation, with the "Ginkgo" species possibly a .^[25] Additionally, fossil flora of and cf. Archaeopteris sp. have been described from the formation.^[26] In the continental sandstone facies of the Cuche Formation, ichnofossils of Diplichnites have been described.^[27]

Fishes[]

Antarctilamna (Gondwanan)

Bothriolepis (Euramerican)

Holoptychius (Euramerican)

The fossil assemblage of the Cuche Formation is unique in the mixture of typical Euramerican (Laurussian) and Gondwanan fish and flora species.

A closer paleogeographical relation between the paleocontinents has been suggested to explain this curious combination.

Remains of the cartilaginous fish Antarctilamna sp., the Placoderms Asterolepis sp. and two species of Bothriolepis,^[28] the spiny shark , the Porolepiform Holoptychius sp., and the Rhizodontid ?Strepsodus sp. have been uncovered from the Cuche Formation.^[23] Several other fossils are less well recognizable at the genus level, among others Actinopterygii, Sarcopterygii,^[29] and Osteolepiformes.^[30] The fish specimens were found in sediments possibly representing localized transgressive marine incursions into brackish lagoonal settings,^[20][31] in all cases associated with the presence of bivalves, ostracods and brachiopods.^[32]

The fossil fish assemblage of the Cuche Formation presents a curious mixture of Euramerican "Old Red Sandstone" (Catskills, Greenland, Scotland and the Baltic states)^[20] species (Asterolepis and Holoptychius), and Gondwanan taxa (Antarctilamna), suggesting the interchange of species between the paleogeographical regions, possibly at closer distance than is presented in most paleogeographical models.^[33][34] This hypothesis is further strengthened by the discovery of typical Euramerican flora, as Archaeopteris.^[26]

Asterolepis has been known only from Euramerican fossils, except for a specimen found in Iran.^[20] The fish of the Cuche Formation are quite different from Bolivian Devonian fossils, with the exception of Antarctilamna. The similar sediments of the in Bolivia have not provided the species discovered in the Cuche Formation, probably because of the cooler climate of the Devonian Bolivian seas more to the south than the paleogeographical position of northern Colombia (already around 51°S) at that time.^[34]

Fossils assigned to , and were later described from the Cuche Formation.^[35][36][37]

Eurypterids[]

In 2019, fragments of the eurypterid Pterygotus were retrieved from the formation. The find represents the first sea scorpion from Colombia and the fourth from South America.^[38] The specimen (SGC-MGJRG.2018.I.5), assigned with uncertainty to P. bolivianus due to similarities with its holotype, represents the first eurypterid of Colombia and the fourth of South America. The fossil was dated as Frasnian (Late Devonian), showing that Pterygotus did not become extinct during the Middle Devonian as previously thought.^[39]

Outcrops[]

Type locality of the Cuche Formation in the north of the Altiplano Cundiboyacense

The Cuche Formation is found at the Floresta Massif around its type locality in Floresta, Boyacá, stretching across Floresta to the west close to Belén and Paz de Río,^[2][40] up to north of Tibasosa in the valley of the Chicamocha River.^[41]

Regional correlations[]

Stratigraphy of the Llanos Basin and surrounding provinces

Ma	Age	Paleomap	Regional events			proximal Llanos	distal Llanos			Environments	Maximum thickness	Petroleum geology	Notes
0.01	Holocene		Holocene volcanism Seismic activity	alluvium								Overburden
1	Pleistocene		Pleistocene volcanism Andean orogeny 3 Glaciations		Soatá Sabana					Alluvial to fluvial (Guayabo)	550 m (1,800 ft) (Guayabo)		[42][43][44][45]
2.6	Pliocene		Pliocene volcanism Andean orogeny 3 GABI		Subachoque
5.3	Messinian		Andean orogeny 3 Foreland		Marichuela				Honda				[44][46]
13.5	Langhian		Regional flooding		hiatus					Lacustrine (León)	400 m (1,300 ft) (León)	Seal	[45][47]
16.2	Burdigalian		Miocene inundations Andean orogeny 2							Proximal fluvio-deltaic (C1)	850 m (2,790 ft) (Carbonera)	Reservoir	[46][45]
17.3										Distal lacustrine-deltaic (C2)		Seal
19										Proximal fluvio-deltaic (C3)		Reservoir
21	Early Miocene		Pebas wetlands						Barzalosa	Distal fluvio-deltaic (C4)		Seal
23	Late Oligocene		Andean orogeny 1 Foredeep							Proximal fluvio-deltaic (C5)		Reservoir	[43][46]
25										Distal fluvio-lacustrine (C6)		Seal
28	Early Oligocene									Proximal deltaic-marine (C7)		Reservoir	[43][46][48]
32	Oligo-Eocene				Usme		onlap			Marine-deltaic (C8)		Seal Source	[48]
35	Late Eocene									Coastal (Mirador)	240 m (790 ft) (Mirador)	Reservoir	[45][49]
40	Middle Eocene				Regadera				hiatus
45
50	Early Eocene									Deltaic (Los Cuervos)	260 m (850 ft) (Los Cuervos)	Seal Source	[45][49]
55	Late Paleocene		PETM 2000 ppm CO2		Bogotá
60	Early Paleocene		SALMA	Barco	Guaduas					Fluvial (Barco)	225 m (738 ft) (Barco)	Reservoir	[42][43][46][45][50]
65	Maastrichtian		KT extinction		Guadalupe					Deltaic-fluvial (Guadalupe)	750 m (2,460 ft) (Guadalupe)	Reservoir	[42][45]
72	Campanian		End of rifting										[45][51]
83	Santonian							Villeta/Güagüaquí
86	Coniacian
89	Turonian		Cenomanian-Turonian anoxic event		Chipaque	Gachetá	hiatus			Restricted marine (all)	500 m (1,600 ft) (Gachetá)	Source	[42][45][52]
93	Cenomanian		Rift 2
100	Albian				Une	Une		Caballos		Deltaic (Une)	500 m (1,600 ft) (Une)	Reservoir	[46][52]
113	Aptian				Fómeque					Open marine (Fómeque)	800 m (2,600 ft) (Fómeque)	Source (Fóm)	[43][45][53]
125	Barremian		High biodiversity		Paja					Shallow to open marine (Paja)	940 m (3,080 ft) (Paja)	Reservoir	[42]
129	Hauterivian		Rift 1		Las Juntas	hiatus				Deltaic (Las Juntas)	910 m (2,990 ft) (Las Juntas)	Reservoir (LJun)	[42]
133	Valanginian				Macanal Rosablanca					Restricted marine (Macanal)	2,935 m (9,629 ft) (Macanal)	Source (Mac)	[43][54]
140	Berriasian			Girón
145	Tithonian		Break-up of Pangea		Arcabuco					Alluvial, fluvial (Buenavista)	110 m (360 ft) (Buenavista)	"Jurassic"	[46][55]
150	Early-Mid Jurassic		Passive margin 2	La Quinta	Noreán	hiatus				Coastal tuff (La Quinta)	100 m (330 ft) (La Quinta)		[56]
201	Late Triassic												[46]
235	Early Triassic		Pangea		hiatus							"Paleozoic"
250	Permian
300	Late Carboniferous		Famatinian orogeny						()				[57]
340	Early Carboniferous		Fossil fish Romer's gap		Cuche (355-385)	()				Deltaic, estuarine (Cuche)	900 m (3,000 ft) (Cuche)
360	Late Devonian		Passive margin 1	Río Cachirí (360-419)					()	Alluvial-fluvial-reef (Farallones)	2,400 m (7,900 ft) (Farallones)		[54][58][59][60][61]
390	Early Devonian		High biodiversity	Floresta (387-400)						Shallow marine (Floresta)	600 m (2,000 ft) (Floresta)
410	Late Silurian
425	Early Silurian			hiatus
440	Late Ordovician		Rich fauna in Bolivia	(450-490)		()
470	Early Ordovician		First fossils		(>470±22)	()		()	() Venado (470-475)				[62][63][64]
488	Late Cambrian		Regional intrusions	(490-515)	()	()		(490-590)	()				[65][66]
515	Early Cambrian		Cambrian explosion										[64][67]
542	Ediacaran		Break-up of Rodinia		pre-Quetame		post-Parguaza		()	Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province)		Basement	[68][69]
600	Neoproterozoic		Cariri Velhos orogeny	(600-1400)				pre-Guaviare					[65]
800			Snowball Earth										[70]
1000	Mesoproterozoic		Sunsás orogeny			(1000)			(1030-1100)				[71][72][73][74]
1300						pre-Ariarí	(1300-1400)		(1180-1550)				[75]
1400				pre-Bucaramanga									[76]
1600	Paleoproterozoic						(1500-1700)		pre-Garzón				[77]
1800							(1800)						[75][77]
1950							pre-Mitú						[75]
2200			Columbia
2530	Archean												[75]
3100			Kenorland
Sources

Legend

• group
• important formation
• fossiliferous formation
• minor formation
• (age in Ma)
• proximal Llanos (Medina)^{[note 1]}
• distal Llanos (Saltarin 1A well)^{[note 2]}

See also[]

Geology of the Eastern Hills

Geology of the Ocetá Páramo

Geology of the Altiplano Cundiboyacense

Bogotá, Cerrejón, Paja Formations, Honda Group

Notes[]

References[]

Bibliography[]

Geology[]

• Geoestudios &, . 2006. Cartografía geológica cuenca Cordillera Oriental - Sector Soapaga, 1–239. . Accessed 2017-05-05.
• Giraldo Gallego, Diana Andrea. 2014. Antropónimos muiscas en la Colonia (1608-1650). Forma y Función 27. 41–94. Accessed 2017-05-05.
• Mojica, Jairo, and Carlos . 1984. Contribución al conocimiento de las unidades paleozoicas del área de Floresta (Cordillera Oriental Colombiana; Departamento de Boyacá) y en especial al de la Formación Cuche. 13. 55–80. Accessed 2017-05-05.
• Pardo Díaz, Marta Yolima; Marta Liliana Gil Padilla; Laura Natalia Garavito Rincón; Pedro Corredor Vargas; Carolina Gutiérrez Barrios; Wilson Parra, and Nancy Amaya Pedraza. 2014. Estudios técnicos, económicos, sociales y ambientales Complejo de Páramos Altiplano Cundiboyacense, 1–546. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt & CORPOBOYACÁ.
• Rodríguez Gutiérrez, Madeleidy. 2017. Criterios de Análisis y Validación del Comportamiento de los Túneles con Squeezing en Rocas, 1–541. Escuela Colombiana de Ingeniería Julio Garavito.
• Rodríguez Parra, Antonio José, and Orlando Solano Silva. 2000. Mapa Geológico del Departamento de Boyacá - 1:250,000 - Memoria explicativa, 1–120. INGEOMINAS.
• Villafañez Cardona, Yohana. 2012. Análisis de procedencia de areniscas cuarzosas del Devónico-Carbonífero de la Formación Floresta (Norte de Santander): Consideraciones paleogeográficas regionales, 1–89. EAFIT.

Paleontology[]

• Zapata Ramirez, Héctor; Alan Pradel; Carlos Martinez Pérez; Philippe Janvier; James C. Lamsdell; Pierre Gueriau; Nicolas Rabet; Philippe Duranleau-Gagnon, and Andres L. Cardenas Rozo. 2019. New insights into Late Devonian vertebrates and associated fauna from the Cuche Formation (Floresta Massif, Colombia). Journal of Vertebrate Paleontology e1620247. 1–18. Accessed 2019-10-09. doi:10.1080/02724634.2019.1620247
• Gómez Cruz, Arley de Jesús; Mario Moreno Sánchez, and Alexander Lemus Restrepo. 2015. Diplicnites isp. del Devónico y Carbonífero de Colombia, _. Tercer Simposio Latinoamericano de Icnología, Colonia de Sacramento, Uruguay. Accessed 2017-05-05.
• Morzadec, Pierre; Michal Mergl; Carlos ; Philippe Janvier, and Patrick R. Racheboeuf. 2015. Trilobites and inarticulate brachiopods from the Devonian Floresta Formation of Colombia: a review. Bulletin of Geosciences 90. 331–358. Accessed 2017-05-05.
• Giroud López, Marie Joëlle. 2014. El Mar en la Localidad Tipo del Devónico Medio, del Municipio de Floresta - Boyacá, Colombia, 1–174. Universidad de La Habana. Accessed 2017-05-05.
• Berry, Christopher M.; Eduardo Morel; Jairo , and Carlos . 2000. Devonian plants from Colombia, with discussion of their geological and palaeogeographical context. Geological Magazine 137. 257–268. Accessed 2017-05-05.
• Janvier, Philippe, and Carlos . 2000. Devonian vertebrates from Colombia. Palaeontology 43. 729–763. Accessed 2017-05-05.
• Janvier, Philippe, and Carlos . 1998. Los Peces Devónicos del Macizo de Floresta (Boyacá, Colombia). Consideraciones taxonómicas, bioestratigráficas, biogeográficas y ambientales. 23. 3–18. Accessed 2017-05-05.

Maps[]

• Renzoni, Giancarlo, and Humberto Rosas. 2009. Plancha 171 - Duitama - 1:100,000, 1. INGEOMINAS. Accessed 2017-06-06.
• Ulloa, Carlos E.; Álvaro Guerra, and Ricardo Escovar. 1998. Plancha 172 - Paz de Río - 1:100,000, 1. INGEOMINAS. Accessed 2017-06-06.
• Renzoni, Giancarlo; Humberto Rosas, and Fernando Etayo Serna. 1998. Plancha 191 - Tunja - 1:100,000, 1. INGEOMINAS. Accessed 2017-06-06.

External links[]

• (in Spanish) Peces devónicos de Colombia, diversidad en los mares y ríos de hace 410-355 millones de años