| Computer Code: |
RGST |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Early Triassic Epoch (TE)
— Early Triassic Epoch (TE) |
| Lithological Description: |
Dominantly red and some grey mudstones with calcareous beds (rogenstein), generally less than 1 m thick, which contain abundant ferruginous ooliths; thin beds of fine sandstone, siltstone and dolomite occur, and traces of anhydrite may be present. The member typically displays gamma-ray and velocity log signatures similar to those shown by the underlying Bunter Shale Formation mudstones but differentiated by the presence of low gamma-ray and high velocity peaks generated by the oolitic beds. |
| Definition of Lower Boundary: |
The base of the Rogenstein Member is placed at the base of the lowest occurrence of ooliths and of the associated low gamma-ray and high velocity peaks. |
| Definition of Upper Boundary: |
The top of the Rogenstein Member corresponds to the top of the Bunter Shale Formation and is placed at an abrupt downward increase in the proportion of mudstone below the dominantly arenaceous Bunter Sandstone Formation. The boundary is marked by an abrupt downward increase in gamma-ray values and, in some logs, by a downward decrease in velocity. |
| Thickness: |
Thicknesses range from about 100 m to more than 210 m. |
| Geographical Limits: |
The Rogenstein Member occurs throughout an area extending westwards from the Cleaver Bank High to the west side of the Sole Pit Trough and northwards to the Silver Pit Basin and North Dogger Shelf. |
| Parent Unit: |
Bunter Shale Formation (BTSH)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
North Sea well 49/21- 2 (Rhys, 1974): 1683-1798.5 m (5522-5901 ft) below KB (metric conversion revised). The top of the member in this section is here revised from 1695.5 m (5563 ft, metric conversion revised) (Rhys, 1974) to the level of a regionally consistent log-marker. |
| Reference Section |
North Sea well 43/20- 1: 1737-1948.5 m (5699-6392 ft) (Johnson et al., 1994). |
| Reference(s): |
| Johnson, H, Warrington, G and Stoker, S J. 1994. 6. Permian and 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. |
| Rhys, G H. 1974. A proposed standard lithostratigraphic nomenclature for the southern North Sea and an outline structural nomenclature for the whole of the (UK) North Sea. Report of the Institute of Geological Sciences, 74/8. |
| Van der Zwan, C J, and Spaak, P. 1992. Lower to Middle Triassic sequence stratigraphy and climatology of the Netherlands, a model. Palaeogeography, Palaeoclimatology, Palaeoecology 91, 277-290. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
