Tectonic controlled sedimentary features at the NE marigin of the Sorgenfrei-Tornquist Zone (STZ), southern Sweden
- 1Uppsala University, Geophysics, Earth Sciences, Uppsala, Sweden (yaocen.pan@geo.uu.se) (christopher.juhlin@geo.uu.se)
- 2University of Hamburg, CEN-Center for Earth System Research and Sustainability, Institute of Geophysics (elisabeth.seidel@uni-hamburg.de) (christian.huebscher@uni-hamburg.de)
- 3Geological Survey of Sweden (SGU) (daniel.sopher@sgu.se)
The Hanö Bay basin was formed during Late Cretaceous transgression as a sedimentary trough on the NE margin of the Sorgenfrei-Tornquist Zone (STZ), a narrow NW-SE striking intraplate inversion zone within the Fennoscandian Border Zone. Sedimentation within the basin was primarily controlled by inversion tectonics, resulting in a coarse-grained syn-inversion clastic wedge forming adjacent to the basin-bounding fault in the Santonian-Maastrichtian. Previous studies have highlighted the deposition of contourite sediments associated with topographic relief of the chalk sea created by such local inversion-induced uplift. Imaged upper Cretaceous clinforms in the marginal trough show a NE-ward progadational character, that is, away from the uplifted and eroded inversion zone. These extend along the inversion axis all the way to NE of the Mid-Polish trough.
To gain detailed stratigraphic constraints and to better understand the interaction of these syn-sedimentary features that developed during inversion tectonics, we use a combination of high-resolution multichannel seismic data (MCS) from the 2019 AL526 cruise and a number of key profiles from reprocessed 70-80’s legacy industry MCS. Preliminary results suggest a drift-moat system developed during a stepwise uplift of the SW shoulder of the STZ, with the uplift driven by transpressional reactivation of basement faults. The resultant aggradational wedge formed a shelf-margin extending fairly far into the basin. The overlying clinoform depositional successions clearly demonstrate several depositional stages; including highstand-progradation, highstand-aggradation and distinct transgression-retrogradation, during which an overall landward migration of the paleo-shoreline position is revealed. The results constrain relative sea-level changes in this area that were primarily related to tectonic events during the Santonian-Campanian.
How to cite: Pan, Y., Seidel, E., Hübscher, C., Juhlin, C., and Sopher, D.: Tectonic controlled sedimentary features at the NE marigin of the Sorgenfrei-Tornquist Zone (STZ), southern Sweden, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3608, https://doi.org/10.5194/egusphere-egu2020-3608, 2020