Schaller, Sebastian (2025). ICDP DOVE Project: Investigating the erosion and infilling of overdeepened Alpine valleys by combining scientific drilling with geophysical exploration. (Thesis). Universität Bern, Bern
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Abstract
The DOVE (Drilling Overdeepened Alpine Valleys) project studies the evolution of the pan-Alpine landscape during the numerous Middle and Late Pleistocene glaciations. Since glaciers often erode older records, sedimentary infills of overdeepened valleys, which are protected from subsequent glacial erosion, offer unique archives for reconstructing past glaciation, paleoclimate, and landscape evolution. Supported by the International Continental Scientific Drilling Program (ICDP), sediment cores and geophysical data from several glacially overdeepened troughs in the Northern Alpine foreland were recovered to study these processes. Geologically, the thesis focuses on DOVE site 5068_2, where a 250-meter-thick succession of unconsolidated Quaternary sediments was recovered from the Basadingen Trough (NE Switzerland), a glacial overdeepening located in the western part of the former Rhine Glacier lobe. In the first part, the thesis focuses on reconstructing the formation history of the Basadingen Trough. Sedimentological analysis, high-resolution reflection seismic data, seismic facies analysis, and core-to-seismic correlation were combined to establish a glacioseismic sequence stratigraphy. The valley fill was grouped into three overdeepened glacial sequences (S1–S3). These sequences reflect three separate pulses of glacial advance and retreat. A local geological 3D model was created to visualize the spatial features of these sequences. This approach overcame perspective limitations and aided in developing a local glaciation model for the Basadingen Trough. The second focus of this thesis is the development of new approaches for the data-based and systematic investigation of glacially overdeepened valleys, adapting methods from the exploration industry. The thesis tests the potential of combining core drilling, borehole measurements, and geophysical data with advanced data analysis to improve the comparability between the different DOVE sites. Therefore, the established glacio-seismic sequence stratigraphy was developed into a more generic and adaptive model that can be applied to similar settings in formerly glaciated areas. Further, a newly developed workflow combines core drilling and borehole measurements to predict the lithology of the drilled sediments. The petrophysical and chemical borehole data-based lithoprediction was validated against core data and successfully extrapolated to a nearby borehole lacking a core, simulating an artificial core. This study demonstrates the potential of integrating geological and geophysical datasets for systematic, data-driven investigations of glacially overdeepened valleys. The methods provide a foundation for future research in formerly glaciated landscapes, enhancing our understanding of glaciation dynamics, paleoclimate evolution, and sedimentary processes.
| Item Type: | Thesis |
|---|---|
| Dissertation Type: | Cumulative |
| Date of Defense: | 28 February 2025 |
| Subjects: | 500 Science > 550 Earth sciences & geology |
| Institute / Center: | 08 Faculty of Science > Institute of Geological Sciences |
| Depositing User: | Hammer Igor |
| Date Deposited: | 17 Apr 2025 14:21 |
| Last Modified: | 17 Apr 2025 20:00 |
| URI: | https://boristheses.unibe.ch/id/eprint/6030 |
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