TECTONIC-SEDIMENTARY EVOLUTION OF JURASSIC IN VIKING GRABEN, THE NORTH SEA

The Jurassic contains the major source rock in the Viking Graben, with shallow-marine sandstones and deep-water submarine-fan sandstones as main reservoirs. Careful study of tectonic-sedimentary evolution is the key to oil and gas exploration. The Jurassic in the Viking Graben could be divided to two phases:Early-Middle Jurassic thermal subsidence and Late Jurassic active stretching phases. In the early stage of the thermal subsidence phase, marine depositional environments prevailed. But in the Middle Jurassic stage it is dominated by a non-marine delta depositional system. In the phase of active stretching, there formed a deep-water submarine-fan system. Based on the facts mentioned above, two tectonic-sedimentary models were established for the Jurassic in Viking Graben of the North Sea.