The BGS Lexicon of Named Rock Units — Result Details
Niarbyl Formation
| Computer Code: | NBY | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Wenlock Epoch (SW) — Wenlock Epoch (SW) | ||
| Lithological Description: | A thin- to medium-bedded wacke sandstone, interbedded with siltstone and mudstone, locally including laminated carboniferous siltstone and thin beds of meta-bentonite. | ||
| Definition of Lower Boundary: | The visible contacts are all faulted against Manx Group and the Peel Formation. It is likely that both lower and upper stratigraphical contacts are unconformable - the lower on the Manx Group where distinguished by being sandstone-dominated facies as opposed to mudstone, the upper probably with overlying Permian or Triassic red-bed facies. | ||
| Definition of Upper Boundary: | Not seen, see above. | ||
| Thickness: | About 1200 m thick. | ||
| Geographical Limits: | Isle of Man. | ||
| Parent Unit: | Dalby Group (DALBY) | ||
| Previous Name(s): | Niarbyl Flags [Obsolete Name And Code: See NBY]
(NBF)
Manx Slate Series [Obsolete Name and Code: Use NBY, CRMR, DALBY, MANX] (-3975) Manx Slates [Obsolete Name and Code: Use MANX] (MXSL) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | The Niarbyl to Glen Maye. Morris et al., 1999 | ||
| Reference(s): | |||
| Geological Survey. 1898. Isle of Man. Sheet 36,45,46 and 57. Solid and Drift geology. 1:63 360 scale. Reprinted at 1:50 000 scale by Institute of Geological Sciences 1975 (Southampton: Ordnance Survey). | |||
| Lamplugh G W. 1903. The geology of the Isle of Man. Memoir Geological Survey of Great Britain. | |||
| Simpson A. 1963. The stratigraphy and tectonics of the Manx Slate Series. Quarterly Journal of the Geological Society of London, Vol. 119, 367-400 | |||
| Chadwick, R A, Jackson, D I, Barnes, R P, Kimbell, G S, Johnson, H, Chiverell, R C, Thomas, G S P, Jones, N S, Riley, N J, Pickett, E A, Young, B, Holliday, D W, Ball, D F, Molyneux, S G, Long, D, Power, G M and Roberts, D H. 2001. Geology of the Isle of Man and its offshore area. British Geological Survey Research Report, RR/01/06. | |||
| Morris J H, Woodcock N H and Howe M P A. 1999. The Silurian succession in the Isle of Man: the late Wenlock Niarbyl Formation, Dalby Group. 189-211 in "In sight of the suture" the palaeozoic geology of the Isle of Man in its lapetus Ocean context. Woodcock N H, Fitches W R, Quirk D G and Barnes R P (editors). Geological Society of London, Special Publication No. 160. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E400 | |||