Geometry and late-stage structural evolution of Central Graben salt diapirs, North Sea

摘要: Abstract Central Graben salt diapirs may have initiated along extensional faults and evolved into in Triassic times. The lack of primary rim synclines indicates that the structures became diapiric without going through a pillow phase. Diapirs grew mainly by downbuilding, probably with sporadic periods subtle bathymetric relief created at diapir crests to Miocene period. Sea-bed controlled deposition Palaeocene turbidite sandstones, which thicken away from 0 up 300 m. However, highest-density turbidity currents flowed across good-quality channel sandstones were deposited tops diapirs. Radial top level concentrate elongate terminations elliptical diapirs, or above deeper cross-fault intersections more circular In map view, radial tend cluster three six main groups. These can be very productive zones chalk reservoir some them been active Recent. Concentric also formed Top Palaeocene, especially parallel NW–SE regional fault trend. disappear as strain decreases upward structure, so only are observed Oligocene above. Diapir growth temporarily ceased end burial Eocene-early strata. Important unconformities locally developed during mid-Miocene times high-angle (up 5°) onlap reflectors unconformities, indicate high sea-bed (>300 m) was rapidly due reactivation This rejuvenation is interpreted caused compression, recognisable around Compression thought produced downslope sliding overburden Zechstein on Eastern Platform area late Alpine shortening whole middle