The Barun Goyot Formation (also known as Baruungoyot Formation or West Goyot Formation) is a

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

dating to the Late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Period. It is located within and is widely represented in the

Gobi Desert The Gobi Desert ( Chinese: 戈壁 (沙漠), Mongolian: Говь (ᠭᠣᠪᠢ)) () is a large desert or brushland region in East Asia, and is the sixth largest desert in the world. Geography The Gobi measures from southwest to northeast a ...

Basin, in the Ömnögovi Province of

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million ...

Description

It was previously known as the Lower Nemegt Beds occurring beneath the

Nemegt Formation The Nemegt Formation (also known as Nemegtskaya Svita) is a geological formation in the Gobi Desert of Mongolia, dating to the Late Cretaceous. The formation consists of river channel sediments and contains fossils of fish, turtles, crocodilians, ...

and above the

Djadokhta Formation The Djadochta Formation (sometimes transcribed and also known as Djadokhta, Djadokata, or Dzhadokhtskaya) is a highly fossiliferous geological formation situated in Central Asia, Gobi Desert, dating from the Late Cretaceous period, about 75 mill ...

. It has been suggested that the Djadokhta and Barun Goyot Formations are lower and upper parts, respectively, of the same lithological unit and the boundary between the two does not exist. The stratotype of the Barun Goyot Formation is the Khulsan locality, east of Nemegt. At Nemegt, only the uppermost barungoyotian beds are visible. The ''Red Beds of Khermeen Tsav'' are also considered part of the Barun Goyot Formation. It is approximately in thickness,Gradzinski, R.; & Jerzykiewicz, T. (1974). Sedimentation of the Barun Goyot formation. Palaeontologica Polonica, 30, 111-146. and was laid down roughly 72-71 million years ago. Given the new date for the start of the

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 inte ...

(72.1 MYA) a basal Maastrichtian age seems probable. The Barun Goyot Formation preserves an environment of

sand dunes A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, fl ...

, created from wind-eroded rocks ( aeolian dunes).

Paleobiota of the Barun Goyot Formation

Lizards

Mammals

Dinosaurs

Alvarezsaurs

Ankylosaurs

Birds

Ceratopsians

Dromaeosaurs

=Halszkaraptorines

Pachycephalosaurs

Oviraptorosaurs

Sauropods

Gallery

File:10 2 Proti Kermen Tsav (34).JPG File:10 2 Proti Kermen Tsav (31).JPG File:Khermen Tsav - Shambala gate - panoramio.jpg File:Hermen Tsav - panoramio.jpg File:Nemegt and Baruungoyot Formations.png

References

{{Reflist Geologic formations of Mongolia Upper Cretaceous Series of Asia Sandstone formations Geologic formations with imbedded sand dunes Aeolian deposits