The first formal lithostratigraphic nomenclature for this offshore area was proposed in a UK–Norwegian collaborative report by Deegan and Scull (1977)
that spanned the Norwegian and UK national offshore areas of the North Sea. Subsequent formal revisions have taken place separately in all three sectors: in Norway by Vollset and Doré (1984), in Denmark by Jensen et al. (1986) and Andsbjerg and Dybkjær (2003), and in the UK by Richards et al. (1993).
Distribution and thickness
The Broom Formation is easily identified in the Brent - Statfjord area in the Norwegian sector of the North Sea. In parts of the East Shetland Basin a thin distal equivalent of the Broom Formation is present within the shales of the Drake Formation. The Broom Formation is recognised throughout most of the East Shetland
Basin where it is generally less than 50 m thick and shows a gradual thinning from west to east. Brown et al. (1987) noted that the formation increases in thickness on the eastern, downthrown side of syndepositional faults (Husmo et al., 2002).
In the type well it is a pale grey to brown, coarse-grained poorly sorted conglomeratic sandstone containing shale clasts.
Middle Jurassic, Late Toarcian to Bajocian.
The Broom Formation is a shallow marine deposit, and is a precursor of the regression which characterizes the overlying Rannoch Formation.
References in scientific journals:
Andsbjerg, J, and Dybkjær, K. 2003. Jurassic sequence stratigraphy of the Danish Central Graben. in The Jurassic of Denmark and Greenland.
Surlyk, F, and Ineson, J R (editors). Geology of Denmark Survey Bulletin.
Deegan, C E, and Schull, B J. 1977. A proposed standard lithostratigraphic nomenclature for the Central and Northern North Sea. Report of the
Institute of Geological Sciences, No. 77/25; Bulletin of the Norwegian Petroleum Directorate, No. 1.
Husmo, T, Hamar, G P, Høiland, O, Johannessen, E P, Rømuld, A, Spencer, A M, and Titterton, R. 2002. Lower and Middle Jurassic. 129-155 in The Millennium Atlas: petroleum geology of the central and northern North Sea. Evans, D, Graham, C, Armour, A, and Bathurst, P (editors and co-ordinators). (London: The Geological Society of London.)
Jensen, T F, Holm, L, Frandsen N, and Michelson, O. 1986. Jurassic-Lower Cretaceous lithostratigraphic nomenclature for the Danish Central
Trough. Danmarks Geologiske Undersøgelse, Series A, No.12. (Copenhagen: Geological Survey of Denmark.)
RICHARDS, P C, LOTT, G K, JOHNSON, H D, KNOX, R W O’B, and RIDING, J B. 1993. Jurassic of the Central and Northern North Sea. Lithostratigraphic
Nomenclature of the U.K. North Sea, Vol. 3. KNOX, R W O’B, and CORDEY, W G (editors). (Nottingham: British Geological Survey.)
Vollset, J. and Doré, A. G. (eds.) 1984: A revised Triassic and Jurassic lithostratigraphic nomenclature for the Norwegian North Sea. NPD-Bulletin No. 3, 53 pp.