Bajada Colorada Formation
{{Short description|Geological formation in Argentina}}
{{Infobox rockunit
| name = Bajada Colorada Formation
| image =
| caption =
| type = Geological formation
| period = Valanginian
| age = Late Berriasian-Early Valanginian
~{{fossil range|140|134}}
| prilithology = Sandstone, conglomerate
| otherlithology = Siltstone, claystone
| namedfor =
| namedby = Roll
| year_ts = 1939
| region = Neuquén Province
| country = Argentina
| coordinates = {{coord|39.8|S|69.7|W|display=inline,title}}
| paleocoordinates = {{coord|38.8|S|32.2|W|display=inline}}
| unitof = Mendoza Group
| subunits =
| underlies = Agrio Formation
| overlies = Quintuco & Picún Leufú Formations
| thickness =
| extent = Neuquén Basin
| area =
| map = {{Location map+ | Argentina
| relief = 1
| width = 250
| float = center
| places =
{{Location map~ | Argentina
| lat_deg = -39.8
| lon_deg = -69.7
| mark = Green pog.svg
| marksize = 12
}}
}}
| map_caption =
}}
The Bajada Colorada Formation is a geologic formation of the southern Neuquén Province in the Neuquén Basin of northern Patagonia, Argentina. The formation belongs to the Mendoza Group and is Late Berriasian to Early Valanginian in age. The formation is renowned for preserving fossil remains of Bajadasaurus pronuspinax, a genus of dicraeosaurid dinosaurs named after the formation.
Description
The Bajada Colorada Formation, first defined by Roll in 1939, pertains to the Mendoza Group.Moyano Bohórquez, 2004 It overlies the Quintuco and Picún Leufú Formations and is overlain by the Agrio Formation. The contact with the Agrio Formation is discordant and the unconformity has been dated to 134 Ma.Leanza, 2005, p.151 The formation is laterally equivalent with the Mulichinco Formation.Howell et al., 2005, p.4 The formation comprises red and greenish-brown, fine to coarse grained conglomerates and thick-bedded sandstones with well-developed bands of light brown siltstones and reddish, pinkish grey and purple-reddish claystones.Leanza et al., 2011, p.120 The formation was deposited in a fluvial environment, and the paleoenviroment resembled a braided river system with well-preserved channels and paleosols.Gallina et al., 2014, p.2
X-ray diffraction studies of sediments belonging to the Bajada Colorada Formation have revealed the presence of smectite, chlorite, illite and kaolinite.
Fossil content
The formation has provided fossils of:[https://paleobiodb.org/classic/displayCollResults?collection_no=156241 Bajada Colorada locality] at Fossilworks.org
{{paleobiota-key-compact}}
= Dinosaurs =
== Ornithischians ==
| class="wikitable" align="center" |
| colspan="7" align="center" | Ornithischians of the Bajada Colorada Formation |
|---|
| Genus
! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images |
| Ankylosauria Indet.{{Cite journal|last1=Rozadilla|first1=Sebastián|last2=Agnolín|first2=Federico|last3=Manabe|first3=Makoto|last4=Tsuihiji|first4=Takanobu|last5=Novas|first5=Fernando E.|date=September 2021|title=Ornithischian remains from the Chorrillo Formation (Upper Cretaceous), southern Patagonia, Argentina, and their implications on ornithischian paleobiogeography in the Southern Hemisphere|journal=Cretaceous Research|language=en|volume=125|pages=104881|doi=10.1016/j.cretres.2021.104881|bibcode=2021CrRes.12504881R }}
| Indeterminate | | | | | |
== Sauropods ==
== Theropods ==
| class="wikitable" align="center" |
| colspan="7" align="center" | Theropods of the Bajada Colorada Formation |
|---|
| Genus
! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images |
| Abelisauridae Indet.{{Cite journal|author1=Juan I. Canale |author2=S. Apesteguía |author3=P.A. Gallina |author4=F.A. Gianechini |author5=A. Haluza |year=2017 |title=The oldest theropods from the Neuquén Basin: Predatory dinosaur diversity from the Bajada Colorada Formation (Lower Cretaceous: Berriasian–Valanginian), Neuquén, Argentina |journal=Cretaceous Research |volume=71 |pages=63–78 |doi=10.1016/j.cretres.2016.11.010 |bibcode=2017CrRes..71...63C |doi-access=free |hdl=11336/109121 |hdl-access=free }}
| Indeterminate | | | | | |
| Abelisauroidea Indet.
| Indeterminate | | | | | |
| Deinonychosauria Indet.
| Indeterminate | | | | | |
| Tetanurae Indet.
| Indeterminate | | | | | |
See also
- List of dinosaur-bearing rock formations
- Baños del Flaco Formation, contemporaneous formation of the Mendoza Group in Chile
- Chon Aike Formation, contemporaneous formation of central Patagonia
References
{{reflist|20em}}
= Bibliography =
- {{citation |last1=Gallina |first1=Pablo A. |last2=Apesteguía |first2=Sebastián |last3=Haluza |first3=Alejandro |last4=Canale |first4=Juan I. |year=2014 |title=A Diplodocid Sauropod Survivor from the Early Cretaceous of South America |journal=PLoS ONE |volume=9 |issue=5 |pages=e97128 |doi=10.1371/journal.pone.0097128 |doi-access=free |pmid=24828328 |pmc=4020797 |bibcode=2014PLoSO...997128G |hdl=11336/6526 |hdl-access=free }}
- {{citation |last1=Howell |first1=John A. |last2=Schwartz |first2=Ernesto |last3=Spalletti |first3=Luis A. |last4=Veiga |first4=Gonzalo D. |year=2005 |title=The Neuquén Basin: An overview |url=https://www.researchgate.net/publication/228707509 |journal=Geological Society, London, Special Publications |volume=252 |issue=1 |pages=1–14 |doi=10.1144/GSL.SP.2005.252.01.01 |bibcode=2005GSLSP.252....1H |accessdate=2019-02-14}}
- {{citation |last1=Leanza |first1=Héctor A. |last2=Sattler |first2=Federico |last3=Martínez |first3=Ricardo S.|last4=Carbone |first4=Osvaldo |year=2011 |title=La formación Vaca Muerta y equivalentes (Jurásico tardío-Cretácico temprano) en la Cuenca Neuquina |url=https://www.researchgate.net/publication/262934412 |publisher=XVIII Congreso Geológico Argentino |pages=113–129 |accessdate=2019-02-14}}
- {{citation |last=Leanza |first=Héctor A |year=2005 |title=Las principales discordancias del Jurásico Superior y el Cretácico de la Cuenca Neuquina |url=https://www.researchgate.net/publication/262934306 |journal=Anales de la Academia Nacional de Ciencias Exactas, Físicas y Naturales |volume=57 |pages=147–155 |accessdate=2019-02-14}}
- {{citation |last=Moyano Bohórquez |first=Fernando |year=2004 |title=Los sistemas sedimentarios de la Formación Bajada Colorada (Cretácico Temprano) en el sur de la Cuenca Neuquina, Argentina |url=http://naturalis.fcnym.unlp.edu.ar/id/20120126000088 |publisher=Universidad Nacional de La Plata |pages=1–250 |accessdate=2019-02-14}}
Category:Geologic formations of Argentina
Category:Lower Cretaceous Series of South America
Category:Conglomerate formations
Category:Paleontology in Argentina