Thermal evolution of an intracratonic rift: The Donbas Foldbelt (Ukraine)
Zusammenfassung der Projektergebnisse
The Ukrainian-Russian Pripyat-Dniepr-Donets Basin is a large intracratonic rift formed during the Devonian. It stretches for ~2000 km along the southern margin of the East European Craton, and – with a sediment thickness of >20 km – it is one of the deepest rift structures worldwide. Its folded and inverted part – the Donbas foldbelt – was subject of this project. Although studied extensively for hydrocarbon exploration, a number of questions concerning the evolution of the Donbas still remained unanswered. These include - Timing and magnitude of various erosion, deformation and heating episodes - Age of formation of the main structures of the Donbas - Timing and geodynamic setting of basin inversion For answering these questions, we combined vitrinite reflectance measurements with thermochronological analysis (apatite and zircon fission track and apatite (U-Th)/He analysis) and thermal modelling. In terms of methodology, we showed that applying alpha-ejection corrections on slowly-cooled samples may lead to erroneous overestimations of apatite (U-Th)/He ages. Furthermore, we made use of the kinetic variability of apatite, allowing us to reconstruct the complex thermal history of the Donbas in great detail: Main coalification during early Permian maximum burial was followed by a period of erosion during the late Permian. This late Permian erosion, however, was less significant than previously assumed, whereas Mesozoic and Cenozoic erosion was much more pronounced, making up to 60% of total erosion. The main structure of the Donbas – the Main Anticline running parallel to the basin axis – first formed prior to main coalification during the Permian, presumably as a result of salt tectonic movements in a transtensive setting. Further accentuation took place during late Triassic to early Jurassic Cimmerian deformation related to the accretion of Iran to Europe. The late Triassic and Jurassic were also periods of magmatic activities, but these did not affect the overall thermal field of the Donbas. During the Cretaceous, the Donbas experienced compressive deformation related to Alpine tectonics, which led to inversion and en-block uplift associated with a mega-popup structure and the formation of a detachment fault reaching through the entire crust and into the mantle. Uplift and pop-up was associated with a westward tilting of the main basin axis. During the Cenozoic, the Donbas became thermally inactive.
Projektbezogene Publikationen (Auswahl)
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2006. Thermal evolution of an intracratonic rift basin: the Donbas foldbelt, Ukraine. European Conference on Thermochronology, Bremen, Germany
Cornelia Spiegel, Reinhard Sachsenhofer, Vitaliy Privalov, Martin Danisík
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2007. 300 million years of basin evolution: burial, exhumation and erosion of the Ukrainian Donbas. Sediment 2007, Brixen, Italy
Cornelia Spiegel, Reinhard Sachsenhofer, Martin Danisik, Vitaliy Privalov
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2008. Integrating apatite fission track and (U-Th)/He thermochronology – potentials and problems. Thermochronology Workshop in Gramado, Brazil
Cornelia Spiegel
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2008. Low-temperature thermal evolution of the Azov Massif (Ukrainian Shield, Ukraine) – Implications for interpreting (U-Th)/He and fission track ages from cratons. Tectonophysics 456, 171-179
Martin Danisik, Reinhard Sachsenhofer, Vitaliy Privalov, Elena Panova, Wolfgang Frisch, Cornelia Spiegel
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2008. Quantifying denudation rates with apatite (U-Th)/He thermochronology – do we need an alpha correction? General assembly of the European Geoscience Union, Vienna, Austria
Cornelia Spiegel, Martin Danisik, Barry Kohn, David Belton, Reinhard Sachsenhofer, Andrew Gleadow
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2008. Thermotectonic evolution of the Ukrainian Donbas Foldbelt and Azov massif: evidence from fission track and (U-Th)/He data. FT2008 – The 11th International Conference on Thermochronometry, Anchorage, Alaska
Martin Danisik, Reinhard Sachsenhofer, Vitaliy Privalov, Elena Panova, Wolfgang Frisch, Cornelia Spiegel
