Plottier Formation

Plottier Formation Stratigraphic range: late Coniacian-early Santonian ~86–85 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Neuquén Group  Río Neuquén Subgroup
Underlies	Río Colorado Subgroup  Bajo de la Carpa Formation
Overlies	Sierra Barrosa Formation
Thickness	Up to 25 m (82 ft)
Lithology
Primary	Claystone
Other	Sandstone
Location
Coordinates	37°24′S 69°06′W / 37.4°S 69.1°W / -37.4; -69.1Coordinates: 37°24′S 69°06′W / 37.4°S 69.1°W / -37.4; -69.1
Approximate paleocoordinates	42°12′S 49°24′W / 42.2°S 49.4°W / -42.2; -49.4
Region	Mendoza, Neuquén & Río Negro Provinces
Country	Argentina
Extent	Neuquén Basin
Type section
Named for	Plottier
Named by	Fossa Mancini et al.
Year defined	1938
Plottier Formation (Argentina)

The Plottier Formation is a geologic formation that outcrops in the Argentine Patagonian provinces of Río Negro and Neuquén. It is the younger of two formations belonging to the Río Neuquén Subgroup within the Neuquén Group of the Neuquén Basin, with the oldest rocks dating from the late Coniacian and its youngest maybe from the very start of the Santonian. Formerly, that subgroup was treated as a formation, and the Plottier Formation was known as the Plottier Member.^[1]

Description[]

A section near the Neuquén City airport, north of the town of Plottier, is the type locality of the Plottier Formation.^[2] At its base, this formation grades into the Portezuelo Formation, and it is in turn overlain conformably by the Bajo de la Carpa Formation, a unit of the Río Colorado Subgroup.

The Plottier Formation is the thinnest formation within the Neuquén Group, with a maximum thickness of only 25 metres (82 ft). It is differentiated from the underlying Portezuelo Formation primarily by its higher content of argillites (mud deposits) and was deposited under fluvial conditions. In 2006, a detailed lithostratigraphic and paleoecological study of a section of the Plottier Formation was published. This section contained alluvial deposits laid down by what was essentially a low-gradient wandering river throughout the millions of years, but often was of a single-channel type with little meandering.^[3][1]

Fossil content[]

Few animal fossils are known from this formation, including:^[4]

• titanosaurid sauropods (including "Antarctosaurus" giganteus, Petrobrasaurus puestohernandezi,^[5] Muyelensaurus pecheni and Notocolossus gonzalezparejasi^[6])
• a basal coelurosaurian theropod
• an indeterminate azhdarchid
• chelid turtles and
• Abelisauridae^[7]
• Unenlagiinae
• Ornithopoda
• Aeolosaurini
• Saltasauridae
• Mesoeucrocodylia
• Crocodyliformes
• Ichnofossils
  • Scoyenia sp.
  • Taenidium sp.
• at least one mammal

There are also ichnofossils left on the river's mudflats, as well as fossil freshwater bivalves.^[1]

See also[]

• List of fossil sites
• List of dinosaur bearing rock formations

References[]

Bibliography[]

• Chiappe, Luis M. (1993): Enantiornithine (Aves) Tarsometatarsi from the Cretaceous Lecho Formation of Northwestern Argentina. American Museum Novitates 3083: 1-27. [English with Spanish abstract] PDF fulltext
• Coria, Rodolfo A.; Currie, Philip J.; Eberth, David & Garrido, Alberto (2002): Bird footprints from the Anacleto Formation (Late Cretaceous), Neuquén, Argentina. Ameghiniana 39(4): 453-463. [English with Spanish abstract] PDF fulltext
• Fossa Mancini, E.; E. Feruglio, and J.C. Yussen de Campana. 1938. Una reunión de geólogos de YPF y el problema de la terminología estratigráfica ("A YPF geologists' reunion and the problem of stratigraphy terminology"). Boletín de Informaciones Petroleras 15. 1–67.
• Leanza, H.A.; S. Apesteguia; F.E. Novas, and M.S. De la Fuente. 2004. Cretaceous terrestrial beds from the Neuquén Basin (Argentina) and their tetrapod assemblages. Cretaceous Research 25. 61–87. Accessed 2019-02-16.
• Lockley, Martin; Matsukawa, Masaki; Ohira, Hiroto; Li, Jianjun; Wright, Joanna; White, Diane & Chen, Peiji (2006): Bird tracks from Liaoning Province, China: New insights into avian evolution during the Jurassic-Cretaceous transition. Cretaceous Research 27(1): 33-43. doi:10.1016/j.cretres.2005.10.007 (HTML abstract). Erratum: doi:10.1016/j.cretres.2008.06.002
• Salgado, L.; Coria, R.A. & Chiappe, Luis M. (2005): Osteology of the sauropod embryos from the Upper Cretaceous of Patagonia. Acta Palaeontologica Polonica 50(1): 79–92. PDF fulltext
• Sánchez, María Lidia; Susana Heredia, and Jorge O. Calvo. 2006. Paleoambientes sedimentarios del Cretácico Superior de la Formación Plottier (Grupo Neuquén), Departamento Confluencia, Neuquén (Sedimentary paleoenvironments in the Upper Cretaceous Plottier Formation (Neuquen Group), Confluencia, Neuquén). Revista de la Asociación Geológica Argentina 61. 3–18. Accessed 2019-02-16.

Further reading[]

Wikimedia Commons has media related to Plottier Formation.

• A. B. Arcucci, L. S. Filippi, and J. O. Calvo. 2011. Un nuevo Mesoeucrocodylia Cretácio del norte de la Cuenca Neuquina, Argentina [A new Cretaceous Mesoeucrocodylia from the north of the Neuquen Basin, Argentina]. Revista Brasileira de Paleontologia 14(1):51-60
• L. S. Filippi, J. I. Canudo, J. L. Salgado, A. Garrido, R. García, I. Cerda, and A. Otero. 2011. A new sauropod titanosaur from the Plottier Formation (Upper Cretaceous) of Patagonia (Argentina). Geologica Acta 9(1):1-12
• B. J. González Riga, M. C. Lamanna, L. D. Ortiz David, J. O. Calvo, and J. P. Coria. 2016. A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot. Scientific Reports 6:19165:1-15