The Glueckstadt Graben, a sedimentary record between the North and Baltic Sea in north Central Europe
Introduction
During the last decade, a series of deep seismic lines provided insight into the structure of the crust within the Central European Basin system (CEBS). The area of the Glueckstadt Graben, thereby, has been of interest since the European Geotraverse in an attempt to reveal the deep structure along the transition zone from Precambrian Fenno-Scandian Shield to Caledonian crust of the NW Germany (EUGENO-S Working Group, 1988, Blundell et al., 1992, Blundell, 1999). Recently, the area of the Schleswig–Holstein became of additional interest because seismic and well data were provided by the oil and gas industry through the German Society for Petroleum and Coal Science and Technology (DGMK). In addition, structural maps were published by the Federal Department of Geosciences and Mineral Resources (BGR; Baldschuhn et al., 1996) which cover the area under consideration. Geologically, the Glueckstadt Graben is located between the North Sea and the Baltic Sea, the area of which shows different crustal structures (Abramovitz et al., 1999, Meissner et al., 2002, Krawczyk et al., 2002), and between the Rynkoebing–Fyn High in the north and Elbe–Odra Line (EOL) in the south. Consequently, the Glueckstadt Graben overprints major structural units in the transition area between Baltica and Caledonian–Variscan Europe. Since 1990s and until now, the Thor Suture (or Caledonian Deformation Front, Fig. 1) has been usually considered as the contact between Baltica and Central Europe (e.g., see Pharaoh et al., 1997) while Cocks et al. (1997) favoured the Elbe–Odra Line (EOL) as the major contact zone. A more detailed model of a wedge-like piece of Baltic crust continuing from the Rynkoebing–Fyn High to the EOL has been suggested by the BASIN'96 experiment (DEKORP-BASIN Research Group et al., 1999) and favoured by Bayer et al., 1999, Bayer et al., 2002. Southward of the Glueckstadt Graben, a block with a low-velocity zone in the lower crust was documented between the EOL and the Elbe Fault Zone (e.g., see Aichroth et al., 1992, Thybo, 2001, Scheck et al., 2002). Similar results concerning the EOL as the southernmost boundary of Baltica have been derived from the TOR experiment. However, the interpretation is not straight forward, and the southern margin of the Rynkoebing–Fyn High may serve as an alternative candidate for the Baltica margin at the level of the upper mantle (Gregersen et al., 2002).
Like other Mesozoic Graben structures of the CEBS (i.e., the Horn Graben, Central Graben and the Rheinsberg Trough), the Glueckstadt Graben is superimposed on the complex crustal structure along the SW margin of the Baltica. Within this frame, the Glueckstadt Graben preserves an especially interesting structure because it is one of the parts of the CEBS providing an exceptional archive to decipher details of the stress and strain history of that area. It is the deepest graben structure and shows an interesting development from the Keuper to present, including young subsidence centres indicated as Westholstein Trough and Hamburger Trough in Fig. 2a. However, as almost everywhere within the basin system, the interpretation of seismic data is hampered by massive salt tectonics (Fig. 2b), which developed as salt walls along major faults within the sedimentary cover along the graben structure.
Here, we examine the Late Triassic to recent development of the Glueckstadt Graben by considering the influence of local salt tectonics and the regional tectonic evolution. Indeed, the area of the Glueckstadt Graben is not only the deepest part of the CEBS, but by occupying 23,000 km2, it provides a large “natural laboratory” concerning the effects of salt tectonics in space and time.
Section snippets
Summary of the geological history of the Glueckstadt Graben
The basin structure and fill of the Glueckstadt Graben have been systematically studied since the beginning of the last century mainly in view of oil and gas exploration. Some results of the scientific investigations within this area have been discussed in several publications (Sannemann, 1968, Dohr et al., 1989, Brink et al., 1990, Brink et al., 1992, Baldschuhn et al., 1996, Baldschuhn et al., 2001, Kockel, 2002). Nevertheless, it is useful to discuss some aspects of the major structures
Data and methods
A set of time-migrated seismic reflection lines and well data has been provided by the German oil and gas industry which are handled through the DGMK. Lines with registration times of 8–14 s of TWT provide the possibility to reconsider previous interpretations in detail. Here, we present interpretations of some lines indicated in Fig. 2a, including details which have not been published yet. However, we restrict ourselves to the Late Triassic–Cenozoic interval because the older strata are not
3D structural model
Fig. 4, Fig. 5 display the present day structure and evolution of the Graben area from the Keuper to Quaternary in terms of thickness maps (Fig. 4, Fig. 5, left column) and three-dimensional views of the base of appropriate stratigraphic levels (right columns). The salt structures represent the present-day state; that is, the thickness maps have not been corrected for postsedimentary piercing by rising salt walls.
During the Keuper, rapid subsidence occurred within a central band (Fig. 3, Fig. 4
Seismic patterns within the Glueckstadt Graben
The presence of lengthy salt walls makes seismic correlation from one structural part of the basin to another rather uncertain. The pre-Keuper strata are isolated from the surrounding areas by major salt structures within the deepest part of the Glueckstadt Graben (see line 2 in Fig. 3). However, Middle–Lower Triassic and partially Permian (upper Rotliegend–Zechstein) horizons have been dated within the southern continuation of the central part where the pre-Keuper sequence is well constrained
Summary and conclusions
The Mesozoic–Cenozoic development of the Glueckstadt Graben can be subdivided into four main stages.
- (1)
The main stage of rapid subsidence took place during the Keuper (Late Triassic) although there are reasonable interpretations of the available data (Baldschuhn et al., 2001), indicating that it may have been initialized as early as the Buntsandstein. In this case, however, the initializing process would contradict our basic understanding of initial “tectonic” subsidence because the process would
Acknowledgements
This work is funded within the DFG-SPP 1135 “Dynamics of sedimentary systems under varying stress conditions by example of the Central European Basin system.” In addition, we want to thank the DGMK as representative of the German oil and Gas Industry for supporting us with data. We also thank Stanislaw Mazur, Björn Lewerenz et al. from the SPP 1135 for fruitful discussions. We are grateful to the company Nord-Express (and personally grateful to Mykola Golyarchuk) for free-of-charge transfer of
References (46)
- et al.
Crustal velocity structure across the Tornquist and Iapetus Suture Zones—a comparison based on MONA LISA and VARNET data
Tectonophysics
(1999) - et al.
Crustal structure along the central segment of the EGT
Tectonophysics
(1992) - et al.
An integrated study of the NE German Basin
Tectonophysics
(1999) - et al.
The southern margin of the East European Craton: new results from seismic sounding and potential fields between the North Sea and Poland
Tectonophysics
(2002) - et al.
Permo-Carboniferous magmatism of the NE German basin
Tectonophysics
(1996) - et al.
Evolution of the lower Saxony basin
Tectonophysics
(1987) The legacy of the European Geotraverse
Tectonophysics
(1999)- et al.
Some aspects of the late and post-Variscian development of the Northwestern German Basin
Tectonophysics
(1992) - et al.
Tectonic evolution of the Mid-Polish Trough: modelling implications and significance for central European geology
Tectonophysics
(1995) - et al.
Summary of project TOR: delineation of a stepwise, sharp, deep lithosphere transition across Germany–Denmark–Sweden
Tectonophysics
(2002)
Seismic evidence of Caledonian deformed crust and uppermost mantle structures in the northern part of the trans-European Suture Zone, SW Baltic Sea
Tectonophysics
Origin of the regional stress in the North German basin: results from numerical modelling
Tectonophysics
Interwedging and inversion structures around the trans-European Suture Zone in the Baltic Sea, a manifestation of compressive tectonic phases
Tectonophysics
Seismic and gravity modelling of crustal structure in the Central graben, North Sea. Observations along MONA LISA profile 3
Tectonophysics
Evolution of the Northeast German Basin—inferences from 3D structural modelling and subsidence analysis
Tectonophysics
The Elbe fault System in North central Europe—a basement controlled zone of crustal weakness
Tectonophysics
Tectonic subsidence modelling of the Polish Basin in the light of new data on crustal structure and magnitude of inversion
Sedimentary Geology
Crustal structure along the EGT profile across the Tornquist Fan interpreted from seismic gravity and magnetic data
Tectonophysics
Structural evolution of inverted basins in the Dutch offshore (North Sea)
Tectonophysics
European Cenozoic rift systems
Tectonophysics
Pre-Zechstein structures around the MONNA LISA deep seismic lines in the southern Horn Graben area
Bulletin of the Geological Society of Denmark
Development of the Rotliegend basin in Northern Germany
Geologisches Jahrbuch
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