The Colorado Formation is a
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cre ...
(
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. Campa ...
to
Maastrichtian
The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...
geologic
formation that is exposed within the
Colorado Basin in the southeastern part of
La Pampa Province
La Pampa () is a sparsely populated province of Argentina, located in the Pampas in the center of the country. Neighboring provinces are from the north clockwise San Luis, Córdoba, Buenos Aires, Río Negro, Neuquén and Mendoza.
History
In ...
,
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
. Fossil
dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...
eggs of ''
Sphaerovum erbeni'' have been reported from the nonmarine,
fluvial
A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...
strata
In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...
of this formation.
[Casadio, S., T. Manera, A. Parras, C. L. Montalvo (2002) ''Huevos de dinosaurios (Faveoloolithidae) del Cretácico superior de la Cuenca del Colorado, Provincia de La Pampa, Argentina.'' Ameghiniana. 39(3):285–293.]
Description
The formation overlies the
Paleozoic
The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...
basement
A basement is any Storey, floor of a building that is not above the grade plane. Especially in residential buildings, it often is used as a utility space for a building, where such items as the Furnace (house heating), furnace, water heating, ...
and has an estimated thickness of .
[López, 2017, p.19] The Colorado Formation comprises medium-grained
sandstone
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
s with intercalated
conglomerates with pebbly beds that can be interpreted as
fluvial
A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...
to
alluvial
Alluvium (, ) is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is ...
deposits.
[Hucal eggsite locality A]
at Fossilworks
Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world.
History
Fossilworks was cr ...
.org
See also
*
List of dinosaur-bearing rock formations
This list of dinosaur-bearing rock formations is a list of geologic formations in which dinosaur fossils have been documented.
* List of stratigraphic units with dinosaur body fossils
* List of stratigraphic units with dinosaur trace fossils
** ...
*
List of stratigraphic units with dinosaur trace fossils#Eggs or nests
References
Bibliography
* {{citation , last=López , first=Gisela Romina , year=2017 , title=Sedimentología e inferencias ambientales de los depósitos de la Formación Colorado (Campaniano-Maastrichtiano), Departamento Hucal, Provincia de La Pampa (BSc. thesis) , url=http://www.biblioteca.unlpam.edu.ar/rdata/tesis/x_lopsed290.pdf , publisher=
Universidad Nacional de La Pampa , pages=1–95 , 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
Conglomerate formations of Argentina
Alluvial deposits
Fluvial deposits
Ooliferous formations
Fossiliferous stratigraphic units of South America
Paleontology in Argentina
Geology of La Pampa Province