Individual Project Czech Geological Survey, Brno, Czech Republic

Quantitation and timing uplift and erosion in the West Carpathians, adjacent Bohemian Massif, and Transylvanian Basin in relationship to mass transfer to active sedimentary basins.

Project financed by Grantová agentura České republiky

Investigators: dr. Juraj Francu; dr. Jan Safanda

Problem statement: Insufficient data and insight of real sedimentary systems hampers the in-depth evaluation of geological controls of geohazards such as landslides, flooding, and contaminant transport in river basins. Isolated case studies have been performed, but cross-border regional investigations are still missing in the Danube river basin system. More specifically, the effects and impact of subsidence and uplift on mass transfer need to be better defined.

Aims and objectives: 3D and 2D models of burial and uplift will be built and calibrated by thermal maturity of kerogen and apatite fission tracks. The results will be integrated in mass transfer models. Causal relationships will be formulated between the dynamics of long term geological processes and observed hazardous events. The applicability of the mass transfer models will be tested in different , selected geodynamic systems of the broader Alpine-Carpathian-Panonian-Black Sea region.

Innovation: The evaluation of the geological controls of the sedimentary sources and sinks in different settings will be better addressed by application of unified methodology in the entire studied region. The extent of uplift and erosion will be quantitatively modeled in regions were limited or no data are available. Detailed constraints on timing and reconstruction of deposition and their removal by erosion will improve the understanding of the sequence of tectonic events, such as strata detachment and thrusting.

Added value: High quality data on geophysics, stratigraphy and topography from selected key regions will be integrated in multidimensional basin evolution models. Indicators will be analyzed of thermal history recorded in the sedimentary rocks. New calibration data will be measured on collected core samples: vitrinite reflectance, RockEval Pyrolysis, and biomarkers (CGS Brno), apatite fission tracks (in cooperation with VU Amsterdam). Other modeling tools include heat transfer in foreland basins used at VU Amsterdam. Paleo-heat flow scenarios will be calibrated. Timing of burial and uplift events will be improved using apatite fission track analysis and the thickness of missing units and rate of their erosion will be calculated within the basins and selected sites along the Danube River. Based on above-mentioned data the thermal history recorded in the sedimentary basins in the broader region covering Vienna, Danube, East Slovak, and Transylvanian basins will be restored, using one detailed profile per each area. The thermal history will be used to quantify erosion, sedimentation, and mass transfer with respect to development in current Danube river basin system. The results will provide input for models dealing with sedimentary mass transfer during the past 20 million years.

Methodologies/experiments: The conceptual model of the studied region will be formulated based on the latest geological interpretation of deeper lithospheric evolution, stress field and plate dynamics. Case studies will focus on the Vienna, Danube, East Slovak, and Transylvanian basins, which represent subsidence centers and sinks within the mass budget. West Carpathian Flysch Belt consists of a series of fold-and-thrust belts, which underwent at least two phases of erosion (Fig. 1). The syn-tectonic foreland basins of the Carpathian Flysch Belt, the Central Carpathians, and the Alps are the major sources of the sedimentary material. The PetroMod forward modeling software (IES) will be used to build the 2-3D burial and uplift during the Neogene and Quaternary. Paleontological data will be incorporated in the improved timing of depositional and erosional events, allowing the reconstruction of paleoenvironmental patterns and sea level fluctuations (in cooperation with Bratislava and Amsterdam groups). The sediment compaction will be based on lithological profiles derived from well logs. Heat flow history will be simulated and calibrated using thermal maturity data of kerogen and apatite fission tracks analysis and data on the lithospheric structure and dynamics. The thermal conductivity distribution in different lithological types of sediments will profit from large database of the Geophysical Institute in Prague and previous studies.