| Computer Code: |
LOSE |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Callovian Age (JC)
— Callovian Age (JC) |
| Lithological Description: |
The member comprises sandstones with minor interbedded mudstones normally stacked in upward-coarsening units (although thin upward-fining units are known). In the Beatrice Field area, at least four upward-coarsening cycles can be identified. Upward gradation is normally dark grey, carbonaceous, micaceous and pyritic mudstone with local shell debris to grey and brown, fine-grained, flaser bedded and ripple laminated, silty sandstones with bioturbated bases. The sandstones are overlain by fine- to medium-grained, cross-bedded or parallel-laminated, locally oolitic, sandstones with bivalves and belemnites. Calcite and limonite cement occurs throughout. Bivalves, shell debris, and Rhaxella spicules occur throughout, except in the basal part. See Linsey et al. (1980), Maclennan and Trewin (1989), Stephen et al. (1993) and Stevens (1991). |
| Definition of Lower Boundary: |
The base is defined by the down-section change from sandstones to a thin unit of coal bearing mudstone (Brora Coal Formation). It is marked by two low-velocity spikes on wireline logs. In some sections sandstones rest on a coal seam (equivalent to the onshore Brora Coal). In the eastern part of the member's distribution, sandstones of the Louise Member rest on Lady's Walk Member, Mains Formation, Golspie Formation and Lossiehead Formation. |
| Definition of Upper Boundary: |
The upper boundary is defined by a down-section change from mudstones (basal Carr Member) to sandstones; sharp decrease in gamma-ray values; and an increase in velocity. Where the mudstone at the base of the Carr Member is poorly developed, it is difficult to recognise the boundary without detailed biostratigraphy. |
| Thickness: |
Up to 25 m. |
| Geographical Limits: |
East of the Beatrice Field, Inner Moray Firth (North Sea Quadrants 11, 12, 17 and 18). |
| Parent Unit: |
Beatrice Formation (BETR)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
North Sea well 11/30- 2 between depths 1963 and 1978.5 m below KB (Richards et al., 1993). |
| Reference Section |
North Sea well 11/25- 1 between depths 2959.5 and 2975 m (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. |
| Linsley, P N, Potter, H C, McNab, G and Racher, D. 1980. The Beatrice Oil Field, Inner Moray Firth, UK North Sea. In: Halbouty, M T (ed.) Giant oil and gas fields of the decade, 1968-1978. American Association of Petroleum Geologists, Memoir, 30, 117-129. |
| Maclennan, A M and Trewin, N H. 1989. Palaeoenvironments of the late Bathonian- mid Callovian in the Inner Moray Firth. In: Keen, M C and Batten, D J (eds.) Northwestern European micropalaeontology and palynology, 92-117. [Ellis Horwood, Chichester] |
| Stephen, K J, Underhill, J R, Partington, M A and Hedley, R J. 1993. The genetic sequence stratigraphy of the Hettangian to Oxfordian succession, Inner Moray Firth. In: Parker, J R (ed.) Petroleum geology of Northwest Europe: Proceedings of the 4th conference, 485-505. [Geological Society, London] |
| Stevens, V. 1991. The Beatrice Field, Block 11/30a, UK North Sea. In: Abbotts, I L (ed.) United Kingdom oil and gas fields 25 years commemorative volume. Memoir of the Geological Society, London, 14, 245-252. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
