Drilling into a deep buried valley (ICDP DOVE): a 252 m long sediment succession from a glacial overdeepening in northwestern Switzerland

Schaller, Sebastian; Buechi, Marius W.; Schuster, Bennet; Anselmetti, Flavio S. (2023). Drilling into a deep buried valley (ICDP DOVE): a 252 m long sediment succession from a glacial overdeepening in northwestern Switzerland. Scientific Drilling, 32, pp. 27-42. Copernicus Publications 10.5194/sd-32-27-2023

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The modern Alpine landscape and its foreland were strongly impacted by the numerous glacier ad- vance and retreat cycles during the Middle-to-Late Pleistocene. Due to the overall erosive character of each glaciation cycle, however, direct traces of older glaciations tend to be poorly preserved within the formerly glaciated domains of the pan-Alpine area. Nevertheless, sediments of older glaciations may occur hidden un- der the modern surface in buried glacially overdeepened troughs that reach below the normal level of fluvial erosion (fluvial base level). These sedimentary archives, partly dating back to the Middle Pleistocene period, are of great scientific value for reconstructing the timing and extent of extensive Alpine glaciation, paleocli- mate, and paleoenvironmental changes in the past and help to better understand ongoing and future changes in the pan-Alpine area. Therefore, the International Continental Scientific Drilling Program (ICDP) project DOVE (Drilling Overdeepened Alpine Valleys) targets several of these glacial overdeepened sedimentary basins to re- cover their sedimentary infills. In the frame of the DOVE project, a 252 m long drill core of unconsolidated Quaternary sediments was recovered in northern Switzerland from an over 300 m deep glacially overdeepened structure (“Basadingen Trough”) formed by the former Rhine Glacier lobe system. The recovered sedimentary succession was divided into three stratigraphic units on the basis of lithological and petrophysical characteristics. The lowest unit, deposited below the fluvial base level, consists of an over 200 m thick succession of glacial to (glacio)lacustrine sediments and contains remains of possibly two glaciation cycles. Overlying this lowermost succession, an ∼ 37 m thick fluvial-to-glaciofluvial gravel deposit occurs, which correlates to a locally outcrop- ping Middle Pleistocene formation (“Buechberg Gravel Complex”). The sediment succession is capped by an ∼ 11 m thick diamictic succession interpreted as the subglacial till from the later extensive glaciation, including the regional glaciation during the Last Glacial Maximum. The recovered sediment succession thus supports the proposed multi-phase origin of trough formation and its infill.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences
08 Faculty of Science > Institute of Geological Sciences > Quaternary Geology

UniBE Contributor:

Schaller, Sebastian, Büchi, Marius, Schuster, Bennet, Anselmetti, Flavio

Subjects:

500 Science > 550 Earth sciences & geology
000 Computer science, knowledge & systems

ISSN:

1816-3459

Publisher:

Copernicus Publications

Language:

English

Submitter:

Flavio Anselmetti

Date Deposited:

27 Oct 2023 07:23

Last Modified:

27 Oct 2023 07:23

Publisher DOI:

10.5194/sd-32-27-2023

BORIS DOI:

10.48350/187498

URI:

https://boris.unibe.ch/id/eprint/187498

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