Tannwald (DE) - Site No. 5068_1

(a) Map of basins of the Rhine Glacier, modified after Ellwanger et al. (2011). Three different generations of basins can be identified bounded by D1–D3 unconformities. These unconformities correspond to the second advances of the Rhine glacier in the Würmian, Rissian and Hosskirchian ice ages.

(b) Geological map of the survey area of the Tannwald Basin showing the location of seismic reflection profiles 1–5 and the borehole location indicated by a star (Burschil et al.; 2018).

Overwiev

Overview

Location: (gps daten) East 9° 44‘ 55,11‘‘ / North 47° 59‘ 59,29‘, 587.85 m asl.

Estimated bedrock depth: 153/154 m

Estimated drill hole depth: 163/164 m

Previous investigations: Seismic reflection campaign 2014/2015

Planed investigations:

- Two non-cored flush drill holes

- Core recovery (combined percussion/rotation drilling)

- Wire-line logging of drill hole

- Groundwater measurement installations

- Drill core analysis

Location of the drill site

Location of the drill site

The site is situated to the north of Lake Constance, in an area previously covered several times by ice of Rhine Glacier. The location, however, lies outside the ice extents of the last glaciation. Detailed geophysical surveys have contributed to decipher the geometry of the overdeepened structure.

Seismic line

Above seismic section 1, (b) interpreted structure and seismic facies. Vertical exaggeration, 2.5×. Profile intersections (black numbers), elevation (black

line), seismic transparent regions (white triangle), foresets (white square), faults with offsets >2 m (dark blue), and faults with unknown offsets

(light blue) are shown. Dashed red line - D2 unconformity, Base of the overdeepened valley solid - red line (Burschil et al. ; 2018).

References

Burschil, T., Buness, H., Tanner, D.C., Wielandt-Schuster, U., Ellwanger, D. & Gabriel, G. (2018): High-resolution reflection seismics reveal the structure and the evolution of the Quaternary glacial Tannwald Basin. Near Surface Geophysics, 16/6, 593–610. https://doi.org/10.1002/nsg.12011

Ellwanger D., Wielandt-Schuster U., Franz M. & Simon T. (2011): The Quaternary of the southwest German Alpine Foreland (Bodensee-Oberschwaben, Baden-Württemberg, Southwest Germany). Quaternary Science Journal 60, 306–328. https://doi.org/10.3285/eg.60.2-3.07