| Computer Code: |
ROWF |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Campanian Age (KC)
— Maastrichtian Age (KM) |
| Lithological Description: |
The Rowe Formation consists of chalky limestones which are typically white to greyish white, friable to moderately hard, commonly argillaceous and chertbearing. The presence of abundant chert (flint) bands throughout the unit is a characteristic feature. Terrigenous clay is present as darker coloured thin beds and seams. The formations both above and below the Rowe Formation, i.e the Ekofisk and Jukes formations respectively, are generally chert-free. |
| Definition of Lower Boundary: |
The base of the Rowe Formation is defined by a marked downward increase in velocity but only shows a slight downward decrease in gamma ray values. The sharp increase in velocity is probably related to a significant basinwide regressive hardground surface. |
| Definition of Upper Boundary: |
The character of the log responses for the top of the Rowe Formation is variable, depending on whether the unit is overlain by Paleogene or younger Tertiary or Pleistocene sequences. In a few wells the formation is overlain by Danian chalky limestones (Ekofisk Formation), with the boundary usually being marked by a downward decrease in gamma-ray values, reflecting a lower clay content. The sonic log signature is, however, variable, with some sections showing a downward decrease in velocity (e.g. 44/28-1) and others a downward increase (e.g. 39/7-1). Where the Ekofisk Formation is absent, the Rowe Formation is overlain by Paleocene mudstones and there is a corresponding sharp downward decrease in gamma ray values and increase in velocity (e.g. 44/24-1). |
| Thickness: |
The Rowe Formation ranges up to 380 m in thickness (e.g. well 49/25-1). |
| Geographical Limits: |
The Rowe Formation is widely distributed throughout the Southern North Sea Basin but may vary significantly in thickness due to intra-basinal tectonic controls and post-Cretaceous erosion notably around the Sole Pit Inversion structure. |
| Parent Unit: |
Chalk Group (CK)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
North Sea well 49/24- 1: 635-840 m (2083-2756 ft) Chalk Group (Lott and Knox, 1994). |
| Reference Section |
North Sea well 44/28- 1: 1651.5-1918.5 m (5418-6294 ft) (Lott and Knox, 1994). |
| Reference Section |
North Sea well 49/05- 1: 1041.5-1265.5 m (3417-4152 ft) (Lott and Knox, 1994). |
| Reference Section |
North Sea well 47/10- 1: 635-840 m (2083-2756 ft) (Lott and Knox, 1994). |
| Reference Section |
North Sea well 53/04- 2: 858.5-1125.5 m (2817-3693 ft) (Lott and Knox, 1994). |
| Reference(s): |
| Lott, G K and Knox, R W O'B. 1994. 7. Post-Triassic of the Southern North Sea. In: Knox, R W O'B and Cordey, W G (eds.) Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. |
| Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. |
| NAM and RGD (Nederlandse Ardolie Maatschappij and Rijks Geologische Dienst) 1980. Stratigraphic nomenclature of the Netherlands. Transactions of the Royal Dutch Geological and Mining Society of Delft. |
| Whitham, F. 1993. The stratigraphy of the Upper Cretaceous Flamborough Chalk Formation north of the Humber, north-east England. Proceedings of the Yorkshire Geological Society, Vol.49, 235-258. |
| Wood, C J and Smith, E G. 1978. Lithostratigraphical classification of the Chalk in North Yorkshire, Humberside and Lincolnshire. Proceedings of the Yorkshire Geological Society, Vol. 42, 263-287. |
| McArthur, J M, Thirwalll, M F, Gale, A S, Kennedy, W J, Burnett, J A, Mattey, D, and Lord, A R. 1993. Strontium isotope stratigraphy for the Late Cretaceous: a new curve, based on the English Chalk. In: Hailwood, E A, and Kidd, R B (eds.) High Resolution Stratigraphy. Geological Society of London, Special Publication, No. 70, 195-209. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
