TRIASSIC TO EARLY CRETACEOUS STRATIGRAPHIC AND STRUCTURAL DEVELOPMENTOF THE NORTHEASTERN MORE BASIN MARGIN, OFF MID-NORWAY

The oldest sedimentary rocks penetrated by exploration wells on the no rtheastern More Basin margin are of Early Triassic age. These sediment s were deposited in a continental, arid climate. A large hiatus separa tes these sedimentary rocks from the overlying Jurassic strata of Bath onian age, which were deposited in a humid continental environment. Ma rginal marine conditions were first established in early Callovian tim es, and late Middle Jurassic to earliest Cretaceous sediments were dep osited in a fully marine anoxic to suboxic environment. Early Cretaceo us sediments were deposited in a dominantly oxic, marine environment. Extensional tectonic movements were probably initiated during Early to Middle Triassic times. This caused erosion of local highs, while basi nal areas underwent subsidence and sediment accumulation. A phase of u plift and erosion rook place between late Early Jurassic and early Mid dle Jurassic times. In Bathonian times rift movements resumed, but fau lt block rotation was relatively gentle and gradual until the end of t he Kimmeridgian. Extension and fault block rotation accelerated in ear ly Volgian times, and climaxed in middle Volgian times, resulting in p resent day dips of up to 50 degrees. The area went into a thermal rela xation phase in earliest Cretaceous times with relatively uniform subs idence, although some of the major Faults remained active until Turoni an times.