| Computer Code: |
NUNV |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Cisuralian Epoch (PLC)
— Cisuralian Epoch (PLC) |
| Lithological Description: |
The Nun Volcanics Formation comprises altered, red to purple, fine-grained, strongly vesicular ?trachyandesitic lavas with a felsic groundmass and abundant microphenocrysts of plagioclase. |
| Definition of Lower Boundary: |
The base of the formation is not defined, as no wells have penetrated it. |
| Definition of Upper Boundary: |
The top of the Nun Rock Volcanics Formation is marked by a downward change from Solan Bank Formation pebbly or conglomeratic sandstones, to lavas. No wireline logs were run within the Nun Volcanics Formation. |
| Thickness: |
The Nun Volcanics Formation has only been encountered in well 205/27a-1 on the Solan Bank High, where it attained an unbottomed thickness of only 1.6 m. |
| Geographical Limits: |
Seismic data suggests that the formation is present under a large part of the West Shetland and West Orkney basins (Hitchen et al., 1995). |
| Parent Unit: |
Rotliegend Group (RLG)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
North Sea well 205/27a- 1: 2700.2-2701.8 m TD (8859-8864 ft) (Ritchie et al., 1996). |
| Reference(s): |
| Ritchie, J D, Gatliff, R W and Riding, J, 1996. 1. Pre - Tertiary lithostratigraphy. In: Stratigraphic Nomenclature of the UK North West Margin. British Geological Survey, Nottingham. |
| 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.) |
| Hitchen, K, Stoker, M S, Evans, D, and Beddoe-Stephens, B. 1995. Permo- Triassic sedimentary and volcanic rocks in basins to the north and west of Shetland. In: Boldy, S A R (ed.) Permian and Triassic rifting in Northwest Europe, Geological Society Special Publication, 91, 87-102. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
