The BGS Lexicon of Named Rock Units — Result Details
Aylesbeare Mudstone Group
Computer Code: | AYB | Preferred Map Code: | Ayb |
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Status Code: | Full | ||
Age range: | Early Triassic Epoch (TE) — Early Triassic Epoch (TE) | ||
Lithological Description: | The undivided Aylesbeare Mudstone Group consists of reddish-brown silty mudstone and clayey siltstone; clayey fine-grained sandstone occurs locally, and less commonly, clean, fine- to medium-grained sandstone. | ||
Definition of Lower Boundary: | Where undivided the Aylesbeare Mudstone rests on red-brown sandstone of the Dawlish Sandstone, possibly unconformably. See Clyst St Lawrence Formation and Exmouth Mudstone and Sandstone Formation for definition of base where those formations are present. | ||
Definition of Upper Boundary: | Overlain sharply by the Budleigh Salterton Pebble Beds. | ||
Thickness: | 530m on south coast (Selwood, et al, 1984); about 400m in Exeter district. | ||
Geographical Limits: | Extends from south Devon coast between Exmouth and Budleigh Salterton in a north-south trending belt to area west of the Quantocks (Sheet 295). | ||
Parent Unit: | New Red Sandstone Supergroup (NRS) | ||
Previous Name(s): | Lower Marls
(-663)
Aylesbeare Mudstone Formation [Obsolete Name and Code: Use AYB] (-3185) Exmouth Beds [Obsolete Name and Code: Use AYB] (-3186) Aylesbeare Group [Obsolete Name and Code: Use AYB] (-1321) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Type Section | Sea cliffs between Exmouth [SY 003 805] and Budleigh Salterton [SY 059 815]. See Exmouth Mudstone and Sandstone Formation, and Littleham Mudstone Formation. | ||
Type Area | Named by Smith, et al. (1974) as the village of Aylesbeare, Devon. | ||
Reference(s): | |||
Laming, D J C, 1966. Imbrication, palaeocurrents and other sedimentary features in the Lower New Red Sandstone, Devonshire. Journal of Sedimentary Petrology, Vol.36, p.940-959. | |||
Smith, D B and 4 others, 1974. A correlation of Permian rocks in the British Isles. Journal of the Geological Society of London, Vol.130, 1-45. | |||
Edwards, R A, Scrivener, R C, Barton, C M, Bristow, C R, Williams, B J, Goode, A J J, Cornwell, J D, Royles, C P, Self, S J, Warrington, G, Riley, N J, Turner, N, Jones, N S, Smith, S A, Marks, R J, Fortey, N J, Morton, R D, Strong, G E, Kemp, S J, Forster, A, Ault, L, Haslam, H W and Chesley, J T. 1999. Geology of the country around Exeter. Memoir of the British Geological Survey, Sheet 325 (England and Wales). | |||
Ussher, W A E. 1902. The Geology of the country around Exeter. Memoir of the Geological Survey of Great Britain, Sheet 325. (England and Wales). | |||
Edwards, R A, 1984. Geological notes and local details for 1:10 000 Sheet SY08NW, (Woodbury, Devon). British Geological Survey. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
E310 E311 E326 E340 E341 E342 E343 |