摘要：

The Mitterndorf Basin is the largest Pleistocene Basin in Austria. The basin is linked to a releasing bend along the major Vienna Basin transfer fault. Basin formation is supposed to start during the Middle Pleistocene. The up to 170 m of accumulated Quaternary sediments show strong variations in their lithofacies reflecting distinct climate oscillations. Massive coarse grained sediments provide huge pore space making the Mitterndorf Basin to one of Europe s largest drinking water reservoirs. Knowledge about the basin's stratigraphy is therefore not only crucial to better understand this important aquifer, basin's subsidence and associated preservation of lithofacies provide also valuable information on Quaternary climate and environment. Intense field and lab work was supported by computer data processing. All data concerning geology (e.g. drill logs, field and lab data), geophysics (e.g. Bouguer gravity, geoelectric data, seismic data) and geography (e.g. aerial images, topographic information) were integrated in a geographic information system (GIS). This major database builds the platform for all static and forward models. Within the 3 years of this PhD, 3 scientific papers have been written so far: Salcher and Wagreich (2008) investigated the impact of climate and tectonic on the lithofacies in the Mitterndorf Basin. The coarse grained, massive facies is associated with high-energetic flood events reflecting a distinct nival regime during glacial times. In contrast, fine grained, well stratified sediments mark periods of rather high discharge to sediment supply ratios during warmer periods. Sequence preservation was provided by subsidence rates of approx. 0.5 to 1 mm per year. High subsidence rates preserve a relatively large record of sequences compared to fluvial terraces which reflect mainly sediments deposited during and shortly after glacials. New 14C and relative ages demonstrate the strong impact of oscillations in climate on fluvial stratigraphy covering times from the upper period of MIS 3 to the MIS 1. Salcher, Meurers, Decker, Wagreich (2008) applied a technique in Bouguer gravity filtering to high pass near surface structures. Different first order derivates of gravity data were used to precisely determine fault locations. Together with drill log information a new and considerably more accurate model of the Mitterndorf Basin's underground was developed. The presented model demonstrated the kinematic (sinistral, pull apart basin) impact on the basin geometry and on fault activity during the Pleistocene. Abundant geophysical and geological data such as 2 D, 3 D seismic, geoelectric, log and outcrop data were used to verify coincidence of structural features with gravity anomalies gained from derivatives. Additionally, numerical models were carried out to better understand effectiveness of derivatives and better interpret gravity anomaly features. Results do not only demonstrate the impact of faults on landscape development. It could be demonstrated that diverse geomorphologic features have a tectonic origin such as scarps, grabens and valleys. Salcher, Meurers, Decker, Wagreich (2008) have been among the first to apply gravity high pass filtering technique in general and the first who demonstrate the suitability in a continental Pleistocene Basin. Salcher, Faber, Wagreich (2008) used a numerical model approach to investigate climate induced aggradation and degradation cycles, the influence of subsidence and the impact of base-level change (Danube) on this large Pleistocene basin within a time frame of 25 ka. Models were carried out as landscape evolution models describing long term changes in size, shape and relief of landforms. Models were calibrated on real world conditions benefiting from abundant data of the study area. New codes were tested and implemented. Software (SedTec) provided excellent calibration possibilities, helping to make models more realistic. Our models showed that adjustments in sediment supply mainly impact basin's sequence evolution. Strong alterations in sediment supply are related

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