Triassic evolution in the Barents sea, Norwegian and Russian sectors: A seismic and sequence stratigraphic approach

摘要

Seismic and sequence stratigraphic analysis methods have been used in subdividing the Triassic section in the Barents Sea, the Norwegian and Russian sectors, into sequences.The boundaries bounding the sequences between the two sectors, and 20 sequence boundaries have been correlated, including the base and top Triassic sequence boundaries. Several causes for sequence boundary formation are suggested, both eustatic sea level changes and sea level changes due to regional or local tectonism, and each sequence boundary has been assigned to one of these causes. Transport directions have been interpreted from downlapping relations and directions of prograding clinoforms. Probable locations of clastic sources are indicated from the transport directions. These clastic sources were located in the area of the Ural Mountains, the Novaya Zemlya Islands, the northern part of the Baltic Shield, north-east of Franz Josef Land, and north-west of the studied area. Additional minor clastic sources have been interpreted in the Loppa High area and in the area of the Fedynsky Arch - Central Barents High. Reservoirs as sand bodies in for example deltas developing close to the paleo-coastline are most probably found in lower-most Triassic strata in the Norwegian sector. Possible additional Triassic reservoirs are basin-floor fans or sands transported via incised valleys and deposited in distal positions during lowstand periods. Such reservoirs were most probably deposited during Late Triassic times. A third type of reservoir may be located north of the Fedynsk Arch - Central Barents High barrier and may have been deposited as high velocity north of the Fedynsk Arch - Central Barents High barrier and may have been deposited as high velocity coastal currents passing the barrier slowed down north of the barrier an no longer could keep coarse material as sand in suspension. Probable locations for the three types of reservoirs are indicated. (ERA citation 19:032291)