The Cerro Fortaleza Formation, in older literature described as Pari Aike Formation, is a

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

geologic

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary ...

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campani ...

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...

age (although it has formerly been reported to be Cenomanian to

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. ...

)Varela et al., 2012 of the Austral Basin in southern

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...

Description

The

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 of the formation were deposited in a

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluv ...

environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...

. The formation has an estimated thickness of and overlies the Anita Formation, while it is overlain by the La Irene Formation.Marenssi et al., 2003, p.406 These formations are considered Campanian & Maastrichtian in age, respectively,Marenssi et al., 2003, p.406Varela et al., 2012 making the Cerro Fortaleza Formation aged between them. The giant

titanosaur Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still th ...

s ''

Puertasaurus ''Puertasaurus'' is a genus of sauropod dinosaur that lived in South America during the Late Cretaceous Period. It is known from a single specimen recovered from sedimentary rocks of the Cerro Fortaleza Formation in southwestern Patagonia, Arge ...

'' and ''

Dreadnoughtus ''Dreadnoughtus'' is a genus of titanosaurian sauropod dinosaur containing a single species, ''Dreadnoughtus schrani''. ''D. schrani'' is known from two partial skeletons discovered in Upper Cretaceous (Campanian to Maastrichtian; approximately ...

'', the

megaraptora Megaraptora is a clade of carnivorous tetanuran theropod dinosaurs with controversial relations to other theropods. Its derived members, the Megaraptoridae are noted for their elongated hand claws and proportionally large arms, which are usually ...

n '' Orkoraptor'', ''

Austrocheirus isasii ''Austrocheirus'' is an extinct genus of theropod dinosaur, possibly a neoceratosaurian, which existed during the Late Cretaceous period. It was named and described by Martin Ezcurra, Federico Agnolin and Fernando Novas in 2010. It contain ...

'', and the

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous worl ...

Talenkauen ''Talenkauen'' is a genus of basal iguanodont dinosaur from the Campanian or Maastrichtian age of the Late Cretaceous Cerro Fortaleza Formation, formerly known as the Pari Aike Formation of Patagonian Lake Viedma, in the Austral Basin of San ...

'' have been recovered from the formation alongside turtles and crocodiles.Novas et al., 2008

References

Bibliography

* * * {{cite LSA , last=Varela , first=A.N. , last2=Poiré , first2=D.G. , last3=Martin , first3=T. , last4=Gerdes , first4=A. , last5=Goin , first5=F.J. , last6=Gelfo , first6=J.N. , last7=Hoffmann , first7=S. , year=2012 , title=U-Pb zircon constraints on the age of the Cretaceous Mata Amarilla Formation, Southern Patagonia, Argentina: Its relationship with the evolution of the Austral Basin , url=http://www.andeangeology.cl/index.php/revista1/article/view/V39n3-a01/2866 , journal=

Andean Geology ''Andean Geology'' (formerly ''Revista Geológica de Chile'') is a peer-reviewed scientific journal published three times per year by the National Geology and Mining Service, Chile's geology and mining agency. The journal covers the field of geo ...

, volume=39 , pages=359–379 , accessdate=2018-09-07 Geologic formations of Argentina Upper Cretaceous Series of South America Cretaceous Argentina Campanian Stage Maastrichtian Stage of South America Sandstone formations Fluvial deposits Formations Fossiliferous stratigraphic units of South America Paleontology in Argentina Geology of Patagonia Geology of Santa Cruz Province, Argentina

Description

See also

References

Bibliography