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Tim Pharaoh, British Geological Survey (United Kingdom)
Piotr Krzywiec, Polish Geological Institute (Poland)
Mark Geluk, Shell Exploration & Production (Netherlands)
Franz Kockel, Consultant (Germany)
Magdalena Scheck-Wenderoth, GeoForschungsZentrum (Germany)
Hans Thybo, Geological Institute (Denmark)
Ole Vejbaek, Hess Denmark Aps (Denmark)
Jan-Diederik van Wees, TNO-NITG (Netherlands)
Michiel Dusar, Geological Survey of Belgium (Belgium)
Charlotte Krawczyk, GGA (Germany)
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A brief review of the evolution of the Southern Permian Basin (SPB) region from late Neoproterozoic to Carboniferous time focuses on the progressive accretion of crust during the Caledonian and Variscan 'orogenic cycles'. This was when the distinctive character of the regional lithosphere was established, with consequences for subsequent basin development. Fundamental crustal lineaments were established, including the Sorgenfrei- and Teisseyre-Tornquist Zones, the Dowsing-South Hewett Fault Zone, and the Central European Fault System, which were to play a significant role during basin evolution, and subsequent inversion. Assembly of Pangea was completed at the end of the Variscan Orogeny, following development of an extensive Permo-Carboniferous magmatic province, and the scene was set for Permian regional subsidence as decay of the lithospheric thermal anomaly resulted in post-orogenic collapse.
For Permian, Mesozoic and Cenozoic time, a series of detailed palaeogeographic reconstructions and basin evolution syntheses are presented. These are supported by tectonic templates derived from the GIS mapping carried out within the project. Deposition of thick Zechstein evaporite sequences in the regional sag basin was to exert a strong influence on the subsequent structural evolution of the basin system. During Triassic time, a prominent system of N-S trending rifts, i.e. the Central, Horn and Glckstadt graben developed. Subsidence of the Mid-Polish Trough was facilitated by transtensional movements along the Teisseyre-Tornquist Zone. During the Jurassic, crustal separation between Gondwana and Eurasia led to wholesale reorganisation of the SPB system. Some of the Triassic rifts became inactive. New E-W trending basins, e.g. the Lower Saxony Basin, developed upon a reactivated Variscan structural template. Rapid subsidence resumed in the late Jurassic following development of a magmatic dome in the central North Sea and continued into the early Cretaceous. Late Cretaceous deposition occurred in a regime of regional thermal subsidence.
Phases of closure of the Neo-Tethys Ocean and the developing Alpine Orogen created intra-plate stress, resulting in inversion. The Alpine orogenic welt propagated westward. The style of inversion is influenced by many factors: salt thickness controls the degree of decoupling; orientation of the basin and strike-slip elements also played a part. Four pulses of compression and basin inversion are recognised in late Cretaceous-early Cenozoic time. Subsequently tectonic and volcanic activity was largely restricted to rifts such as the Eger and Rhine Valley graben.
The morphology of the SPB will be illustrated by interpreted regional seismic lines and long depth-converted transects from each country published at constant scale. The integration of these data with geophysical potential field, structural and stratigraphic mapping is providing new insights into the initiation and evolution of the region.
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