• Source: Rosablanca Formation

The Rosablanca Formation (Spanish: Formación Rosablanca, Kir) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes and the Middle Magdalena Basin. The formation consists of grey limestones, dolomites and shales with at the upper part sandstones. The formation dates to the Early Cretaceous period; Valanginian epoch and has a thickness of 425 metres (1,394 ft) in the valley of the Sogamoso River.




Definition


The formation was first defined by Wheeler in 1929.




Description






= Lithologies

=
The Rosablanca Formation is characterised by a sequence of grey limestones, dolomites and shales with a maximum thickness of 425 metres (1,394 ft) in the Sogamoso River valley.




= Stratigraphy and depositional environment

=
The Rosablanca Formation overlies the Arcabuco Formation and is overlain by the Ritoque Formation. The age has been estimated to be Valanginian. Stratigraphically, the formation is time equivalent with the Macanal Formation.




= Fossils

=
Fossils of the decapod crustacean Diaulax rosablanca have been found in and named after the Rosablanca Formation. In 2019, fossils of brachiopodSellithyris elizabetha were described from the formation. In 2020 remains of indeterminate pterosaurs were described from the formation, including pterodactyloids and non-Pteranodontian ornithocheiroids. In 2005 the remains of Platychelyid sea turtle Notoemys zapatocaensis were described, and in 2023 the limbs and shell elements of protostegids were described as some of the largest Early Cretaceous turtles.




Outcrops



The Rosablanca Formation is found, apart from its type locality on the Mesa de Los Santos, Santander, in Boyacá and the Middle Magdalena Basin.




Regional correlations



Legend
group
important formation
fossiliferous formation
minor formation
(age in Ma)
proximal Llanos (Medina)
distal Llanos (Saltarin 1A well)




See also



Geology of the Eastern Hills
Geology of the Ocetá Páramo
Geology of the Altiplano Cundiboyacense




Notes and references






= Notes

=




= References

=




= Bibliography

=
Galvis Arenas, Beatriz Elena; Valencia Escobar, José Leonardo (2009), Contribución en la determinación de los posibles paleoambientes de las rocas Cretáceas Tempranas sobre la vía Tunja-Villa de Leyva (entre Alto del Arrayán - Peaje Sáchica) y sectores aledaños, departamento de Boyacá, Universidad de Caldas, pp. 1–127
Gómez Cruz, Arley de Jesús; Bermúdez, Hermann D.; Vega, Francisco J. (2015), "A new species of Diaulax Bell, 1863 (Brachyura: Dialucidae) in the Early Cretaceous of the Rosablanca Formation, Colombia", Boletín de la Sociedad Geológica Mexicana, 67: 103–112, doi:10.18268/BSGM2015v67n1a8, retrieved 2017-04-04
Rojas, Alexis; Sandy, Michael R. (2019), "Early Cretaceous (Valanginian) brachiopods from the Rosablanca Formation, Colombia, South America: Biostratigraphic significance and paleogeographic implications", Cretaceous Research, 96: 184–195, Bibcode:2019CrRes..96..184R, doi:10.1016/j.cretres.2018.12.011, retrieved 2019-02-11
Villamil, Tomas (2012), Chronology Relative Sea Level History and a New Sequence Stratigraphic Model for Basinal Cretaceous Facies of Colombia, Society for Sedimentary Geology (SEPM), pp. 161–216



Maps

Bernal Vargas, Luis Enrique; Mantilla Figueroa, Luis Carlos (2006), Plancha 85 - Simití - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Bernal Vargas, Luis Enrique; Mantilla Figueroa, Luis Carlos (2006), Plancha 96 - Bocas del Rosario - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Vargas, Rodrigo; Arias, Alfonso (2009), Plancha 97 - Cáchira - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Beltrán, Alejandro; Quintero, Claudia I. (2008), Plancha 119 - Barrancabermeja - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Ward, Dwight E.; Goldsmith, Richard; Jimeno, Andrés; Cruz, Jaime; Restrepo, Hernán; Gómez, Eduardo (2010), Plancha 120 - Bucaramanga - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Beltrán, Alejandro; Lancheros, José Alfredo; López, Carolina; Chaquea, Claudia; Patiño, Alejandro; Guerra, Angela; Cabrera, Julio C.; Quintero, Claudia I.; Molano, Simón Emilio (2008), Plancha 134 - Puerto Parra - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Angarita, Leonidas; Carrillo, Víctor; Castro, Alfonso; Daconte, Rommel; Niño, Mario; Pulido, Orlando G.; Rodríguez, J. Antonio; Royero, José María; Salinas, Carlos Ulloa and Rodrigo Vargas, Rosalba (2009), Plancha 135 - San Gil - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Beltrán, Alejandro; Lancheros, José Alfredo; López, Carolina; Chaquea, Claudia; Patiño, Alejandro; Guerra, Angela; Cabrera, Julio C.; Quintero, Claudia I.; Molano, Simón Emilio (2008), Plancha 150 - Cimitarra - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Pulido González, Orlando (2009), Plancha 151 - Charalá - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Ulloa, Carlos E; Rodríguez, Erasmo (2009), Plancha 170 - Vélez - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Renzoni, Giancarlo; Rosas, Humberto (2009), Plancha 171 - Duitama - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Fuquen M., Jaime A; Osorno M, José F. (2009), Plancha 190 - Chiquinquirá - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06
Renzoni, Giancarlo; Rosas, Humberto; Etayo Serna, Fernando (1998), Plancha 191 - Tunja - 1:100,000, INGEOMINAS, p. 1, retrieved 2017-06-06




External links


Gómez, J.; Montes, N.E.; Nivia, Á.; Diederix, H. (2015), Plancha 5-09 del Atlas Geológico de Colombia 2015 – escala 1:500,000, Servicio Geológico Colombiano, p. 1, retrieved 2017-03-16

Kata Kunci Pencarian:

• Rosablanca Formation
• Paja Formation
• 2024 in archosaur paleontology
• List of plesiosaur-bearing stratigraphic units
• Ritoque Formation
• Protostegidae
• List of fossiliferous stratigraphic units in Colombia
• 2019 in brachiopod paleontology
• 2015 in arthropod paleontology
• Platychelyidae