Basadingen (CH)

Overwiev

Location: 47.648, 8.753 (WGS84)

Reached drill depth: 253 m

Previous investigations:

- non-cored flush drilling (~205 m)

- 2D seismic survey by LIAG, ETH and University of Bern (2019)

Planed investigations:

- Core recovery (combined percussion/rotation drilling)

- Wire-line logging of drillhole

- Drill core analysis

Location of the drill site

The drill site BASA (yellow dot on map) will explore the overdeepened Basadingen Trough in Northeastern Switzerland. The Basadingen overdeeping formed during the Middle Pleistocene a valley that connected the Thur Valley in the South with the Rhine Valley in the North. The maximum sediment thickness is of up to 300 m south of the drill site. The seismic site survey revealed a multiphase infilling architecture with possibly two, partly crosscutting generations of erosion/sedimentation cycles. These likely represents different glacial erosion pulses of the western lobe of the Rhine Glacier.

Seismic lines

The seismic site surveys reveal a multiphase stratigraphy showing a series of unconformities (colored lines). This internal architecture indicates that the trough was filled as a result of multiple glacial sequences (bold letters). The overdeepening reaches a maximum depth of ca. 300 m. The coring site (black) is located so that the drill core will recover a maximum number of sequences in well-layered facies including bedrock (Molasse, M), that is expected in ~250 m depth.