Adrian M. Lowe1,
Rob L. Gawthorpe1,
David W. Hunt1,
John R. Underhill2,
Steve H. Anderson3
(1) University of Manchester, Manchester, United Kingdom
(2) Edinburgh University, Edinburgh, United Kingdom
(3) Conoco (UK) Ltd, Aberdeen, United Kingdom
Abstract: Seismic and Sequence stratigraphic evolution of early post-rift deep-water sandstones: The Outer Moray Firth, North Sea
The Barremian to Late Aptian succession of the Outer Moray Firth comprises post-rift deep-water facies infilling antecedent rift bathymetry. A seismic and sequence stratigraphic interpretation of this prospective interval is developed based on the integration of seismic (2D and 3D), log and core data.
Detailed core sedimentological analysis has identified a robust lithofacies scheme which has been used to calibrate log response. These calibrated logs facilitated the identification of ‘wireline log motifs’ that have been assigned to specific deep-water facies associations and are shown to have a spatial and temporal significance.
Four genetic stratigraphic sequences have been identified bounded by major marine flooding surfaces tied to biostratigraphic data. Each genetic sequence being dominated by a unique combination of facies associations. The Early to Middle Barremian sequence (GSI) is dominated by pelagic and hemi-pelagic suspension fallout in a basin-floor setting. The Middle Barremian to Early Aptian sequence (GSII) is dominated by channelised high-concentration sediment gravity flows and is the main reservoir interval. Latest Early Aptian to Late Aptian sequences (GSIII and GSIV) are dominated by mass transport complexes and slope degradation. The change in style of sedimentation and temporal distribution of sediment is interpreted to reflect changes in sediment provenance brought about through relative sea-level change.
Dominant controls on reservoir and sequence development are interpreted to be: basin geometry and physiography, tectonism, relative sea-level and sediment transport and depositional mechanisms.
AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana