Bull Run Formation Explained

Bull Run Formation
Type:	Geological formation
Age:	Norian ~
Period:	Norian
Prilithology:	Mudstone
Otherlithology:	Shale, siltstone
Region:	Maryland, Virginia
Coordinates:	38.9°N -77.4°W
Paleocoordinates:	13.3°N -21.8°W
Unitof:	Chatham Group
Subunits:	Ball's Bluff & Groveton Members
Extent:	Culpeper Basin

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]

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

References

Bibliography

• Hunt, ReBecca K., Vincent L. Santucci and Jason Kenworthy. 2006. "A preliminary inventory of fossil fish from National Park Service units." in S.G. Lucas, J.A. Spielmann, P.M. Hester, J.P. Kenworthy, and V.L. Santucci (ed.s), Fossils from Federal Lands. New Mexico Museum of Natural History and Science Bulletin 34, pp. 63–69
• R. E. Weems. 2006. The manus print of Kayentapus minor: its bearing on the biomechanics and ichnotaxonomy of early Mesozoic saurischian dinosaurs. In J. D. Harris, S. G. Lucas, J. A. Spielmann, M. G. Lockley, A. R. C. Milner, & J. I. Kirkland (eds.), The Triassic-Jurassic Terrestrial Transition. New Mexico Museum of Natural History and Science Bulletin 37:369-378
  • R. E. Weems and P. G. Kimmel. 1993. Upper Triassic reptile footprints and a coelacanth fish scale from the Culpeper Basin, Virginia. Proceedings of the Biological Society of Washington 16(2):390-401
• J. R. Smith. 1982. Dinosaurs in Virginia—evidence of two new genera. Lapidary Journal 36(6):1110-1111
• R. Weems. 1979. A large parasuchian (phytosaur) from the Upper Triassic portion of the Culpeper Basin of Virginia (USA). Proceedings from the Biological Society of Washington 92(4):682-688

Notes and References

1. http://www.fossilworks.org/cgi-bin/bridge.pl?action=collectionSearch&geological_group=Chatham&formation=Bull%20Run Bull Run Formation
2. Hunt et al., 2006, p.64
3. Weishampel et al., 2004, pp.517-607
4. https://ngmdb.usgs.gov/Geolex/Units/BullRun_715.html Bull Run