Fig. 6: The west-plunging offshore Gulen and the east-plunging Vette basement antiforms.

a 3D model, showing seismic sections through the offshore Gulen and Vette antiforms. Both folds are illustrated by an interpreted internal basement reflector (colored surfaces). The Gulen surface is truncated by the top basement unconformity. The two antiforms plunge in opposite directions (W and E, respectively). The erosion line for the mapped Gulen antiform reflector is shown as a dashed dark red line. Strike/dip symbols give the orientation of this surface at several locations, while arrows indicate fold hinges. Only seismic data below the base Cretaceous unconformity (BCU) is shown. b Deeper (−3925 m) horizontal slice through the Gulen Fold, showing how the Øygarden Fault is guided by the fold around the hinge zone. c Vertical section through the fold (yellow line in b). The Øygarden Fault cuts through the folded layers on the south side (F2) of the fold even though being subparallel to the folded layers in map view (b). On the north side (F1) the fault is cutting the basement banding at a much lower angle, and locally exploiting this banding (upper part). Note that the reflectors along and above the orange dashed line in (c) represent Devonian mylonitic banding. Basement is given a red tint in (b) and (c). White dashed lines in all figures are fault traces. The Orange dashed line in (b) marks the intersection between the interpreted horizon in (a) and the horizontal slice in (b). The yellow line in (b) marks the location of the profile shown in (c). The yellow line in (c) marks the constant depth slice shown in (b). The location is approximately that annotated for Fig. 4 (see Fig. 1), but a is shifted slightly southward to cover the Vette antiform.