The Neogene stratigraphy of the glaciated European margin from Lofoten to Porcupine

Stratigraphic-range chart for the Faroe–Shetland region

The latest Palaeogene–Neogene stratigraphic-range chart for the Faroe–Shetland region is based on 23 sample stations, consisting of 8 BGS boreholes and 15 commercial wells. The sample stations are located on the map below. The distribution of the sample stations is predominantly from the West Shetland margin, and extending northwards into the area of the North Sea Fan, supported by some limited information from the Faroe-Shetland Channel. At the time of this study, there was no information from the Faroes margin. 

The intra-Neogene regional unconformity — reflector INU — that separates megasequences FSN-1 and FSN-2 is broadly constrained as an intra-early Pliocene event. On the West Shetland Shelf, information from BGS borehole 77/9 suggests an erosional break between the NN12 and NN13/14 biozones. Elsewhere on the shelf, BGS borehole 84/2 proved sediments of NN15 and younger age overlying the INU. In deep water, well 214/4-1 supports an early Pliocene event. Although the available data are sparse, the biostratigraphic information is not inconsistent with an unconformity located within the interval represented by the NN12–13 biozones. 

The range chart suggests that the base of megasequence FSN-2 essentially marks the base of the Neogene section over a large part of the West Shetland Shelf and Slope. From inspection of the chart, there is fairly strong evidence for a regional late Oligocene–early Miocene unconformity, termed the Top Palaeogene Unconformity (TPU), which is overlain by lower Miocene strata at a number of sites. In contrast, well 214/4-1 located in the NE part of the Faroe-Shetland Channel records no apparent break in sedimentation at the Oligocene–Miocene boundary. However, seismic-stratigraphic and biostratigraphic resolution at this site remain ambiguous. The clarity of the section is further complicated at this site by the occurrence of a siliceous, diagenetic, reflector imaged on profiles at this stratigraphic level. 

Source of data

1. Hitchen, K. 1999. Rockall Continental Margin Project. Shallow Borehole Drilling Programme 1999. Geological Report. British Geological Survey Technical Report, WB/99/21C.

2. Davison, S. 2000. An investigation of the Quaternary sediments from BGS boreholes 99/3, 99/4, 99/5 and 99/6, Faroe-Shetland Channel. British Geological Survey Technical Report, CR/00/27.

3. Davies, R., Cartwright, J., Pike, J. & Line, C. 2001. Early Oligocene initiation of North Atlantic Deep Water formation. Nature, 410, 917-920.

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4. Davies, R. & Cartwright, J. In press. Character and origin of a fossilised bottom simulating reflector originating from Opal A to C/T transformation: an example from the Neogene of NE Atlantic margin. Basin Research.

5. Released well data from Chevron.

6. Released well data from Amoco.

7. Stoker, M.S. 1999. Stratigraphic nomenclature of the UK North West Margin, 3. Mid- to late Cenozoic stratigraphy. British Geological Survey, Edinburgh (ISBN 0 85272 326 1).

8. Harland, R. 1998. A summary compilation of the key dinoflagellate cyst biomarkers for the Oligocene to Pleistocene interval, with a reappraisal of BGS and commercial borehole data. Dinodata Services Report RH/98/03/01. 

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