Bull Run Formation

The Bull Run Formation is a Late Triassic (Norian) stratigraphic unit in the eastern United States.^[1] Fossil fish bones and scales have been found in outcrops of the formation's Groveton Member in Manassas National Battlefield Park.^[2] Indeterminate fossil ornithischian tracks have been reported from the formation.^[3]

Bull Run Formation
Stratigraphic range: Norian ~222–210 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Chatham Group
Sub-units	Ball's Bluff & Groveton Members
Lithology
Primary	Mudstone
Other	Shale, siltstone
Location
Coordinates	38.9°N 77.4°W / 38.9; -77.4
Approximate paleocoordinates	13.3°N 21.8°W / 13.3; -21.8
Region	Maryland, Virginia
Country	United States
Extent	Culpeper Basin
Bull Run Formation (the United States) Show map of the United States Bull Run Formation (Virginia) Show map of Virginia

The Bull Run Formation was once considered part of the Culpeper Group of the Newark Supergroup, but the United States Geological Survey no longer formally recognizes this formation (it is abandoned).^[4]

Fossil content

The following fossils were reported from the formation:^[1]

• Rutiodon cf. manhattanensis

Ichnofossils

• Agrestipus hottoni
• Eubrontes cursorius
• Kayentapus minor
• Grallator (Eubrontes)
• Anomoepus sp.
• Diplurus sp.

See also

• List of dinosaur-bearing rock formations
  • List of stratigraphic units with ornithischian tracks
    • Indeterminate ornithischian tracks