The BGS Lexicon of Named Rock Units — Result Details
Ardnish Formation
Computer Code: | ADS | Preferred Map Code: | AdS |
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Status Code: | Full | ||
Age range: | Hettangian Age (JH) — Sinemurian Age (JS) | ||
Lithological Description: | Sandstone, siltstone, fissile micaceous mudstone, with thin ironstones in the lower section. Gryphaea common. | ||
Definition of Lower Boundary: | Lithology change, grain size decreases. Sporadic ironstones define boundary. | ||
Definition of Upper Boundary: | Overlain by fissile mudstones of the Pabay Shale Formation. | ||
Thickness: | 55 to 78m | ||
Geographical Limits: | Sea of the Hebrides Basin. | ||
Parent Unit: | Lias Group (LI) | ||
Previous Name(s): | Upper Broadford Beds
(-6)
Hallaig Sandstone (-632) |
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Alternative Name(s): | Pabay Shale Formation Hallaig Sandstone Member |
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Stratotypes: | |||
Reference Section | Ardnish Peninsula, Broadford Bay, southern Skye. Hallam, 1959. | ||
Reference(s): | |||
Morton, N. 1999b. Middle Hettangian (Lower Jurassic) ammonites from the Isle of Raasay, Inner Hebrides, and correlation of the Hettangian - lowermost Sinemurian Breakish Formation in the Skye area, north-western Scotland. Scottish Journal of Geology, Vol.35, Part 2, 119-130. | |||
Morton, N. 1999. Discussion of the Lower Lias Group of the Hebrides Basin; reply by Hesselbo, S P, Oates, M J and Jenkyns, H C. Scottish Journal of Geology, Vol.35 Part 1, 85-88. | |||
Hallam, A. 1959. Stratigraphy of the Broadford Beds of Skye, Raasay and Applecross. Proceedings of the Yorkshire Geological Society, Vol.32, 165-184. | |||
Morton, N and Hudson, J D, 1995. Field Guide to the Jurassic of the Isles of Raasay and Skye, Inner Hebrides, north-west Scotland. In: Taylor, P D (editor), Field Geology of the British Jurassic. Geological Society of London, 209-280. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
S071 S081 |