The marine sector of the North German Basin and the Tornquist Zone: Structural evolution and fluid flow

• Applicants: Professor Dr. Christian Hübscher; Dr. Vera Noack
• Subject Area: Geophysics ; Palaeontology
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 396852626

This project aims at reconstructing and understanding the structural evolution and related fluid expulsion in the marine sector (Baltic, Skagerrak and Kattegat) of the North German Basin and the most prominent and longest pre-Alpine tectonic lineament of Europe, the Tornquist Zone. The Tornquist Zone includes the Sorgenfrei-Tornquist and the Teisseyre-Tornquist Zones, both representing the transition area from the Precambrian Baltic Shield to the Caledonian-Variscan Europe.The major objectives are: 1) quantifying structural deformation since the Rotliegend to recent; 2) investigating ice-load induced tectonism; 3) re-assessing salt tectonics in the North German Basin; and 4) exploring sea floor directed fluid escape from Mesozoic and Paleozoic source and reservoir rocks.The related hypotheses are: 1) inversion tectonics lasts until today; 2) with the onset of glacial periods in the middle Pleistocene differential ice load induced tectonism reactivated inherited and created new fault systems, which partly pierce the present day seafloor; 3) gravity gliding was the dominant process that controlled salt deformation along the northern margin of the North German Basin; 4) that the petroleum system in the study area is partly leaky. The goals will be achieved by geophysical and geological methods. The unique core data set comprises ca. 2500 (out of 3500) km of reflection seismic data collected in 2016 with a 2700 km long streamer and eight GI-Guns as seismic source in the Baltic Sea. The short initial offset of 30 m allows for the very first time and in spite of the shallow water depth gapless subsurface imaging from Paleozoic strata up to the seafloor. Depth section with yet unparalleled resolution will be created, enabling us for an accurate fault slip analysis. Based on that we will restore balanced sections, which is necessary to unravel and quantify the mechanisms behind observed structural deformation. The tectono-stratigraphic evolution of the north-western end of the Tornquist Zone in the Skagerrak and Kattegat will be addressed by the integrated analyses of both ca. 1000 km of industrial and 3.200 km reflection seismic data collected during own research expeditions.We will interpret the new seismic data in the context of > 30.000 km of vintage data that image the upper kilometer only. Previous geophysical and geochemical studies provided compelling evidence that fluids escape on the seafloor origin from source and reservoir rocks. Fluid migration paths will be imaged and fluid and lithology properties will be distinguished by AVO-methods and other seismic attributes. We assume that our findings will be applicable also for the adjacent hinterland.

• DFG Programme: Research Grants
• International Connection: Poland, Sweden
• Co-Investigators: Professorin Dr. Katrin Huhn-Frehers; Professorin Dr. Nina Kukowski; Dr. Daniel Kühn; Professor Dr. Wolfgang Rabbel; Professor Dr. Klaus Reicherter; Dr. Martin Thorwart
• Cooperation Partners: Professor Dr. Christopher Juhlin; Professor Dr. Michal Malinowski; Dr. Daniel Sopher