Exploration beneath Tertiary Flood Basalts in the North Faeroe-Shetland and More Basins; Offshore UK
J. Derek Ritchie, Robert W. Gatliff, and Peter Broad
Until recently, exploration within the offshore UK northwest margin has proceeded at a slow pace, with drilling activity restricted to about 100 wells since 1972. However, recent Tertiary discoveries leading to the development of the Foinavon and Schiehallion fields in the Faeroe-Shetland Basin has revitalised interest.
The northwest parts of the Faeroe-Shetland and More basins are poorly defined with the pre-Tertiary structure obscured by flood basalts belonging to the Faeroe Plateau Lava Group. These plume-related lavas are widespread, with over 5km present on the Faeroes and were derived at the time of inception of the Iceland Plume about 62Ma. Paris of the Tertiary succession are also masked by dolerites belonging to the Faeroe-Shetland Sill Complex. These intrusives were associated with the opening of the North Atlantic Ocean about 55-53Ma.
Interpretation of new seismic reflection data (3700km) in the North Faeroe-Shetland and More basins has revealed the presence of patchily developed sub-volcanic reflectors, possibly representing Mesozoic events and even top crystalline basement. This has suggested that the northwest margin of the Faeroe-Shetland Basin extends further than previously anticipated. Integration of potential field and seismic data has proved important in attempting to resolve the deep structure of the North Faeroe-Shetland Basin.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California