Development of extensional growth basins: A field based study, Svalbard, Norway

• Published in: Journal of the Geological Society
• Main Author: Smyrak-Sikora, Aleksandra Anna
• Other Authors: orcid:0000-0001-9321-1269
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: The University of Bergen 2020
• Subjects: Billefjorden; Edgeøya; Kvalpynten; Norway; Svalbard; Spitsbergen
• Online Access: https://hdl.handle.net/1956/21496

The growth style and evolution of syn-sedimentary faults influence the architecture of the basin and thus control both the geometries and distribution of sedimentary facies belts. The architecture of sedimentary basin fill reflects a combination of tectonic and climatic controls that are relatively unique for each geological setting. This statement was tested in Svalbard, Norway, where recent post-glacial topography and a lack of vegetation reveal unique outcrops that allow detailed investigation of spatio-temporal basin fill development. Field studies were conducted in two locations: in the Upper Carboniferous Billefjorden Trough outcropping in central Spitsbergen, and in Kvalpynten, Edgeøya, wherean array Upper Triassic growth faults is exposed. This body of work consists of four scientific articles. Field-based results from detailed sedimentological logging, structural measurements and geological mapping were combined with analysis of three-dimensional outcrop models (derived from LIDAR scans and photogrammetry). Published data such as lithostratigraphy from the boreholes and sedimentary logs were also integrated to form an extensive and coherent database. A ca. 25 km wide basin fill of the Billefjorden Trough records the transition from a continental to a paralic sedimentary facies that formed in response to the opening of a connection to the sea. Early syn-rift deposition occurred in a basin segmented into the hanging wall blocks of meso-scale (tens to hundred meters of displacement) growth faults, in partly isolated sub-basins. In this phase the Billefjorden Trough was a symmetrical basin. Later on, half-graben geometry developed during the rift climax, highlighted by deposition of up to 400 meters of alluvial fan deposits confined to the master fault zone. Meso-scale faults have segmented the dipslope into proximal and distal part. The tectonic impact on the basin fill was the greatest near the master fault zone and in the proximal dipslope. The imprint of eustatic sea level prevails over the 13 tectonic ...