The Lecho Formation is a geological
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 ...
in the
Salta Basin
Salta Basin or Salta Rift Basin is a sedimentary basin located in the Argentine Northwest. The basin started to accumulate sediments in the Early Cretaceous ( Neocomian) and at present it has sedimentary deposits reaching thicknesses of . The basi ...
of the provinces
Jujuy
San Salvador de Jujuy (), commonly known as Jujuy and locally often referred to as San Salvador, is the capital and largest city of Jujuy Province in northwest Argentina. Also, it is the seat of the Doctor Manuel Belgrano Department. It lies near ...
and
Salta
Salta () is the capital and largest city in the Provinces of Argentina, Argentine province of Salta Province, the same name. With a population of 618,375 according to the 2010 census, it is also the List of cities in Argentina, 7th most-populous ...
of northwestern
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 ...
. Its strata date back to the
Early Maastrichtian, and is a unit of the
Salta Group. The fine-grained
bioturbated 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 of the formation were deposited in a
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
lacustrine
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from t ...
coastal plain
environment
Environment most often refers to:
__NOTOC__
* Natural environment, referring respectively to all living and non-living things occurring naturally and the physical and biological factors along with their chemical interactions that affect an organism ...
.
Dinosaur remains are among the fossils that have been recovered from the formation.
[Weishampel et al., 2004, "Dinosaur distribution (Late Cretaceous, South America)." pp. 600-604]
According to Frankfurt and Chiappe (1999), the Lecho Formation is composed of reddish
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. The Lecho is part of the Upper/Late Cretaceous Balbuena Subgroup (Salta Group), which is a near-border stratigraphic unit of the Andean sedimentary basin. Fossils from this formation include the
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 thr ...
''
Saltasaurus
''Saltasaurus'' (which means "lizard from Salta") is a genus of saltasaurid dinosaur of the Late Cretaceous Period (geology), period of Argentina. Small among sauropods, though still heavy by the standards of modern creatures, ''Saltasaurus'' was ...
'' along with a variety of
avian and non-avian
theropods
Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...
.
Fossil content
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
** ...
*
Marília Formation
The Marília Formation is a geological Formation (geology), formation in Minas Gerais state of southeastern Brazil. Its strata date back to the Maastrichtian, and are part of the Bauru Group.
The fossil-bearing Serra da Galga and Ponte Alta member ...
References
Bibliography
*
*
*
* {{citation , last1=Frankfurt , first1=N.G. , first2=L.M. , last2=Chiappe , year=1999 , title=A Possible Oviraptorosaur From The Late Cretaceous of Northwestern Argentina , journal=
Journal of Vertebrate Paleontology
The ''Journal of Vertebrate Paleontology'' is a bimonthly peer-reviewed scientific journal that was established in 1980 by Jiri Zidek (University of Oklahoma). It covers all aspects of vertebrate paleontology, including vertebrate origins, evolu ...
, volume=19 , issue=1 , pages=101–105, doi=10.1080/02724634.1999.10011126 , bibcode=1999JVPal..19..101F
Geologic formations of Argentina
Cretaceous Argentina
Sandstone formations
Fluvial deposits
Lacustrine deposits
Cretaceous paleontological sites of South America
Paleontology in Argentina