Subsidence, Mass And Heat Transfer In The Central European Basin System: A Large-Scale Basin Modelling Study

R. Littke, M. Resak, S. Nelskamp, Y. Adriasola Muñoz, and S. Rodon
Institute for Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr. 4-20, 52056 Aachen, Germany, [email protected]

The Central European Basin system (CEBS) was initiated by rifting and thermal subsidence of the lithosphere during the Early Permian. It is made up of various sub-basins which differ significantly in tectonic style and sedimentary infill. Several studies on the burial, temperature and maturity history of different areas in the Central European Basin were performed revealing a different timing for maximum burial and maximum temperatures. We are going to present results from the Netherlands onshore, the Bramsche Area in the Lower Saxony Basin, the Schleswig-Holstein Area in the North German Basin and the Pomeranian segment of the Mid-Polish Trough.

At the beginning of the Mesozoic the Netherlands were subdivided into different basins due to differential subsidence. The West Netherlands Basin, the Central Netherlands Basin, the western margin of the Lower Saxony Basin, the Broad Fourteens Basin and the Roer Valley Graben are the main structures in this basin system. All major basins in the Netherlands encountered at least one time of inversion and therefore moderate to high amounts of erosion.

In the southwestern part of the Lower Saxony Basin, in the area of Bramsche, evidence for extremely high thermal maturity of coaly organic matter has been found. The central part of the anomaly is characterized by anthracitized coals in lowermost Cretaceous sedimentary rocks, whereas in the peripheral area coalification in the same stratigraphic level does not exceed the lignite stage. There are two different scenarios discussed for the area. One assumes a magmatic intrusion that is responsible for the high thermal maturity, another assumes deep burial and uplift in the Late Cretaceous. We reconstructed the thermal and burial history by testing different scenarios of basin subsidence and uplift including emplacement of igneous intrusions.

In the Schleswig-Holstein area two characteristic features had a strong impact on the maturity distribution in the study area. One is the Glueckstadt Graben, a predominantly Triassic structure, which comprises more than 4,000 m of Triassic sedimentary rocks. The other main characteristic features are NNE-SSW trending salt walls. They strongly influenced the subsidence pattern during their evolution in Mesozoic and Cenozoic times, resulting in high sedimentation rates in deep rim synclines as well as condensed sedimentation in the crestal areas of the salt structures. Furthermore, they also strongly affected the temperature field and therefore also the maturity pattern due to their high thermal conductivities.

Another prominent element of the CEBS is the Mid-Polish Trough situated in the easternmost part. Thick sediments accumulated here since Permian times. We present new numerical models describing quantitatively subsidence, heat flow evolution and inversion with special emphasis on Cretaceous to recent temperature evolution and thickness of sediments eroded during the Late Cretaceous-Early Paleogene inversion.

 

AAPG Search and Discover Article #90066©2007 AAPG Hedberg Conference, The Hague, The Netherlands