| Computer Code: |
RAVL |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Bathonian Age (JN)
— Callovian Age (JC) |
| Lithological Description: |
The Rattray Volcanics Member comprises lavas, volcanics and subordinate clastics. Lavas include ankaramites, alkali olivine basalt, hawaiites and mugearites (Fall et al., 1982). The associated agglomerates, tuffs and tuffaceous claystone may be pyritic, chloritic, sometimes felsic, calcareous and/or glassy. Sandstones and mudstones are locally interbedded with the volcanics. |
| Definition of Lower Boundary: |
The base is placed at a down section change from volcanic rocks to sedimentary successions of either coal-bearing Pentland Formation, Lower Jurassic mudstones, Triassic red beds or Permian evaporites. The volcanic member interdigitates with sedimentary successions. |
| Definition of Upper Boundary: |
The top is defined by the down-section change from dominantly sedimentary deposits to essentially volcanic. Coal-bearing sediments (Pentland Formation) or marine sandstones and mudstones (Piper, Hugin, Heather or Kimmeridge Clay formations) overlie volcanic rocks. The volcanic member interdigitates with sedimentary successions. |
| Thickness: |
Up to 1500 m. |
| Geographical Limits: |
South Viking Graben and northern part of the Central Graben (Quadrants 14-16, 21 and 22). |
| Parent Unit: |
Pentland Formation (PNTL)
|
| Previous Name(s): |
Rattray Formation
(-5144)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
North Sea well 21/10- 1 between 2680 m and 3422.5 m below KB (Deegan and Scull, 1977; Richards et al., 1993). |
| Reference Section |
North Sea well 16/17- 6 between 4874 m and 5135 m (Deegan and Scull, 1977; Richards et al., 1993). |
| Reference Section |
North Sea well 15/18- 2 between 2874 m and 3045 m (Deegan and Scull, 1977; Richards et al., 1993). |
| Reference Section |
North Sea well 21/03b- 3 between 2940 m and 4148 m (Deegan and Scull, 1977; Richards et al., 1993). |
| Reference Section |
North Sea well 22/05b- 4 between 3596.5 m and 4121 m (Deegan and Scull, 1977; Richards et al., 1993). |
| Reference(s): |
| Richards, P C, Lott, G K, Johnson, H, Knox, R W O'B. and Riding, J B. 1993. 3. Jurassic of the Central and Northern North Sea. In: Knox, R W O'B and Cordey, W G (eds.). Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. |
| Deegan, C E and Scull, B J. 1977. A standard lithostratigraphic nomenclature for the Central and Northern North Sea. Report of the Institute of Geological Sciences, 77/25; NPD Bulletin No.1. |
| Fall, H G, Gibb, F G F and Kanaris-Sotiriou, R. 1982. Jurassic volcanic rocks of the northern North Sea. Journal of the Geological Society, London, 139, 277-292. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
