The BGS Lexicon of Named Rock Units — Result Details
Nettle Crags Tuff Member
| Computer Code: | NCT | Preferred Map Code: | NCT |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Caradoc Series (O4) — Caradoc Series (O4) | ||
| Lithological Description: | Massive, eutaxitic to parataxitic dacitic lapilli-tuff. | ||
| Definition of Lower Boundary: | Base of dacitic lapilli-tuff above dacite lavas (and/or sills) within the Birker Fell Andesite Formation. | ||
| Definition of Upper Boundary: | Non-sequence at top of dacitic lapilli-tuff. Overlain by dacite and volcaniclastic sandstone in the Birker Fell Andesite Formation. | ||
| Thickness: | 60-220m | ||
| Geographical Limits: | Nettle Crags - Bootle Fell in the Borrowdale Volcanic Group outcrop between the Skiddaw Group and Eskdale Granodiorite. | ||
| Parent Unit: | Birker Fell Andesite Formation (BFA) | ||
| Previous Name(s): | Part of Nettle Crags Tuffs and Lavas [Obsolete Name and Code: Use NCT]
(-2334)
Nettle Crags Tuff Formation [Obsolete Name and Code: Use NCT] (-1722) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Area | Nettle Crags, 1km east north east of Bootle, Cumbria. | ||
| Reference(s): | |||
| British Geological Survey. 1994. Black Combe and Bootle, SD18NW, Solid and Drift 1:10 000. (Keyworth, Nottingham: British Geological Survey.) | |||
| Mathieson, N A, 1986 Geology, structure and geochemistry of the Ordovician volcanic succession in south west Cumbria. Unpublished Ph.D. thesis, University of Sheffield. | |||
| Johnson, E W, Soper, N J, Burgess, I C, Ball, D F, Beddoe-Stephens, B, Carruthers, R M, Fortey, N J, Hirons, S, Merritt, J W, Millward, D, Roberts, B, Walker, A B and Young, B. 2001. Geology of the country around Ulverston. Memoir of the British Geological Survey, England and Wales, Sheet 48. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E048 | |||