Processing and interpretation of lower crustal seismic events from recently released industry data to study the influence of deep rooted processes on formation and evolution of the North German Basin and their relation to neo-tectonic activities

• Applicant: Professor Dr. Dirk Gajewski
• Subject Area: Geophysics
• Term: from 2004 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5429049

The Schleswig-Holstein area of the Central European Basin System qualifies as an outstanding "natural geo-scientific laboratory" in terms of the geological inventory the available database and with regard to its key role in basin evolution. An extensive database was gathered by the Oil- and Gas Industry. Essential parts of this data base became available for research within the SPP 1135. The acquisition and processing by the industry of the released reflection seismic data was tuned to image the basin sediments down to the Zechstein using basically standard CMP processing which was state of the art in the 80ies. Several of the industry profiles were acquired using long offsets (up to 4.8 km) and long recording times (up to 14 sec TWT). The potential of the data to image the crystalline crust was never optimised and only marginally exploited although structures in the lower crust and partly also some Moho reflections were already visible in the (for the lower crust) brute CMP stacks. Since the structure of the crystalline crust provides important information on the deep processes steering and influencing basin formation we want to exploit the imaging potential of the industry data for the lower crust using contemporary imaging methods like the Common Reflection Surface (CRS) stack and modern pre-stack depth migration techniques as well as migration velocity analysis. Moho depth, Moho releif, Moho diversity and possible metamorphic complexes and their effects on siesmic signatures are some of the key issues do be investigated. Moreover, seismic events within the crystalline crust as well as fault zones and their possible surface extensions are further topics to be discussed. Among others, the new images will help to elucidate how seismic signatures relate to crustal blocks and its tectonic lineaments and how lower crustal structures are leated to gravimetric and magnetic anomalies. They will further provide insight whether there is evidence for Avalonia and of Proterozoic sediments and whether the Moho is related to the 700°C isotherm.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1135: Dynamics of Sedimentary Systems under Varying Stress Regimes: The Example of the Central European Basin System
• Participating Person: Dr. Heinz-Jürgen Brink