Barun Goyot Formation
The Barun Goyot Formation (also known as Baruungoyot Formation or West Goyot Formation) is a geological formation dating to the Late Cretaceous Period. It is located within and is widely represented in the Gobi Desert Basin, in the Ömnögovi Province of Mongolia. Description. It was previously known as the Lower Nemegt Beds occurring beneath the Nemegt Formation and above the Djadokhta Formation. 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, and was laid down roughly 72-71 million years ago. Given the new date for the start of the Maastrichtian (72.1 MYA) a basal Maastrichtian age seems probable. The Barun Goyot Formation preserves an environment of sand dunes, created from wind-eroded rocks (aeolian dunes).