The BGS Lexicon of Named Rock Units — Result Details
Lady's Walk Formation [See also LAWA]
| Computer Code: | LDYW | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Sinemurian Age (JS) — Pliensbachian Age (JE) | ||
| Lithological Description: | The formation comprises dark to medium grey, calcareous, micaceous, shelly mudstone. Upward-fining sandstone-siltstone units, with burrowed bases, occur. | ||
| Definition of Lower Boundary: | The lower boundary is marked by a downward change from dark, fossiliferous mudstone to white to pale grey sandstones with interbedded mudstone (Mains Formation), and a marked down-section decrease in average gamma-ray values and an increase in velocity. | ||
| Definition of Upper Boundary: | The upper boundary is placed between an upward-coarsening siltstone-sandstone unit (Orrin Formation) and mudstone (Lady's Walk Formation). The boundary corresponds to the top of a low velocity spike. Where the Orrin Formation is absent, the upper boundary is placed at a downward change from sandstone (Beatrice Formation) to shelly mudstone, or sandstone and mudstone (Brora Coal Formation) to shelly mudstone. | ||
| Thickness: | Up to 30 m. | ||
| Geographical Limits: | Inner Moray Firth Basin, North Sea UK Quadrants 11, 12, 17, 18. | ||
| Parent Unit: | Dunrobin Bay Group [See Also DRB] (DUNR) | ||
| Previous Name(s): | Dronach Shale Member
(-5107)
Lady's Walk Shale Unit (-5108) |
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| Alternative Name(s): | Lady's Walk Shale Member [See also LDYW] |
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| Stratotypes: | |||
| Type Section | North Sea well 11/30- 4 at 2276.5-2305.5 m depth below KB (Richards et al., 1993). | ||
| Reference Section | North Sea well 12/21- 2 at 2339-2363.5 m depth (Richards et al., 1993). | ||
| Reference Section | North Sea well 12/27- 2 at 1628.5-1653.5 m depth (Richards et al., 1993). | ||
| Reference(s): | |||
| Andrews, I J, and Brown, S. 1987. Stratigraphic evolution of the Jurassic, Moray Firth. 785-795 in Petroleum Geology of North West Europe. Brooks, J, and Glennie, K W (editors). (London: Graham and Trotman.) | |||
| Stevens, V. 1991. The Beatrice Field, Block 11/30a, UK North Sea. In: Abbotts, I L (ed.) United Kingdom oil and gas fields 25 years commemorative volume. Memoir of the Geological Society, London, 14, 245-252. | |||
| Richards, P C, Lott, G K, Johnson, H, Knox, R W O'B. and Riding, J B. 1993. 3. Jurassic of the Central and Northern North Sea. In: Knox, R W O'B and Cordey, W G (eds.). Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. | |||
| Batten, D J, Trewin, N H, and Tudhope, A W. 1986. The Triassic-Jurassic junction at Golspie, Inner Moray Firth Basin. Scottish Journal of Geology, Vol. 22, Pt. 1, 85-98. | |||
| Waters, C N, Gillespie, M R, Smith, K, Auton, C A, Floyd, J D, Leslie, A G, Millward, D, Mitchell, W I, McMillan, A A, Stone, P, Barron, A J M, Dean, M T, Hopson, P M, Krabbendam, M, Browne, M A E, Stephenson, D, Akhurst, M C, and Barnes, R P. 2007. Stratigraphical Chart of the United Kingdom: Northern Britain. (British Geological Survey.) | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| none recorded or not applicable | |||