Structural evolution and fluvio-deltaic sedimentary architecture in salt-influenced rift-basins - examples from the Snadd Formation in the Nordkapp and Tiddlybanken basins

• Main Author: Reppen, Ine
• Other Authors: Ravnås, Rodmar, petroleumsgeologi, petroleum geosciences engineering
• Format: Master Thesis
• Language: English
• Published: University of Stavanger, Norway 2016
• Subjects: Salt mini-basins; Tiddlybanken Basin; Nordkapp Basin; VDP::Technology: 500::Rock and petroleum disciplines: 510::Geological engineering: 513; Barents Sea; Fennoscandia; Nordkapp
• Online Access: http://hdl.handle.net/11250/2414744

Master's thesis in Petroleum geosciences engineering The Nordkapp and Tiddlybanken basins are examples of salt sedimentary basins with thick successions of Triassic-Middle Jurassic fluvio-deltaic basin infill in the Barents Sea. The Middle to Upper Triassic Snadd Formation represent two regressive-transgressive fluvio-deltaic mega-sequences systems extending across the entire Barents Sea. These large fluvio-deltaic systems were generated as a result of the exposure of the Ural Mountains and Fennoscandia. The Nordkapp and Tiddlybanken basins formed during Devonian to Carboniferous, with salt deposited in a shallow evaporitic basin during the Late Carboniferous and Early Permian under the influence of regional extension. Salt growth was initiated in Early-Middle Triassic in the Nordkapp Basin and Middle Triassic in the Tiddlybanken Basin. Several salt mini-basins were formed due to diachronous salt growth in response to differential loading in the Early to Middle Triassic, because of the initial progradation of fluvio-deltaic systems. The fluvial stratigraphic architecture and style in the mini-basins is controlled by the interplay between subsidence rate (and subsequent accommodation creation) and sediment delivery rate. The regressive and transgressive mega-sequences represent two forestepping to backstepping fluvio-deltaic clastic wedges in the Snadd Formation. Depositional environments range from upper delta plain to marine environments, but are mostly occupied by flood- and delta plain environments with various types of fluvial channel systems. The salt diapirism interaction with the fluvio-deltaic systems has generated rim-synclines along the salt walls with large fluvial systems captured by the rim-synclines, resulting in fill-spill infill pattern of the salt mini-basins. In the lower progradational and retrogradational units the dominant fluvial character is meandering to anastomosing, with underfilled conditions in the salt mini-basins. The middle part is a succession with balanced to overfilled basin ...