Title: Comparative stratigraphic and structural evolution of perched Mesozoic rift basins along the eastern margin of the Rockall Tough
Researchers: Dr Stratos Delogkos, Prof. Peter Haughton, Dr Conrad Childs
The Irish Rockall Basin remains a frontier area for petroleum exploration with only three wells and four shallow stratigraphic boreholes along the eastern flank of the basin. The currently under-filled trough deepened significantly during several phases of flank rotation and tilting during the Cenozoic, with basin centred deposition, largely from contour current circulation, dominating since the late Eocene. Thin Cretaceous to Recent successions drape steep marginal slopes to the east and these mantle a series of “perched” fault‐controlled rift basins of Triassic and/or Mid‐Late Jurassic age along the western side of Porcupine High. Investigation of the origin and prospectivity of these poorly-known perched basins is hampered by: (1) a moratorium on new seismic acquisition along the eastern flank of Rockall; (2) uncertain North Atlantic restorations which alternatively place the basins off Labrador or Flemish Pass on the conjugate margin; (3) an unclear NE Atlantic affinity of the basins – are they Hebridean and similar to the Erris–Slyne basins in character or more akin to fault‐controlled basins in south Porcupine; (4) issues with distinguishing Triassic from Mid‐Late Jurassic basin infill in the absence of well control; (5) an association with a poorly understood phase of hyperextension that led to very thin crust beneath the deep troughs to east and west, and (6) poor constraints on the burial, exhumation and thermal history and the likely source rock development and maturation state.
The objective of the work is to provide a robust stratigraphic and structural understanding of the perched Mesozoic rift basins along the eastern margin of the Rockall Trough out-board of Porcupine High and to consider the wider affinity of the basins ahead of a possible 2019-20 Licensing Round. Output from the work will provide the data to underpin subsequent Petroleum Systems studies in the area.