Drilling Overdeepened Alpine Valleys (ICDP-DOVE)

Quantifying the age, extent, and environmental impact of Alpine glaciations

authored by

Flavio S. Anselmetti, Milos Bavec, Christian Crouzet, Markus Fiebig, Gerald Gabriel, Frank Preusser, Cesare Ravazzi, Dove Scientific Team , Daniel Ariztegui, Sarah Beraus, Anna Catharina Brandt, Marius Buechi, Herman Buness, Thomas Burschil, Andreas Dehnert, Gaudenz Deplazes, Gregor Götzl, Gustav Firla, Lukas Gegg, Hans Rudolf Graf, Katja Heeschen, Rolf Kipfer, Ernst Kroemer, Christopher Lüthgens, Giovanni Monegato, Stephanie Neuhuber, Roberta Pini, Jürgen Reitner, Bernhard Salcher, Sebastian Schaller, Clemens Schmalfuss, Cedric Schmelzbach, Robert Scholger, Bennet Schuster, Andrew Stumpf, David C. Tanner, Camille Thomas, Yama Tomonaga, Ulrike Wieland-Schuster, Thomas Wonik

Abstract

The sedimentary infill of glacially overdeepened valleys (i.e., structures eroded below the fluvial base level) is an excellent but yet underexplored archive with regard to the age, extent, and nature of past glaciations. The ICDP project DOVE (Drilling Overdeepened Alpine Valleys) Phase 1 investigates a series of drill cores from glacially overdeepened troughs at several locations along the northern front of the Alps. All sites will be investigated with regard to several aspects of environmental dynamics during the Quaternary, with focus on the glaciation, vegetation, and landscape history. Geophysical methods (e.g., seismic surveys), for example, will explore the geometry of overdeepened structures to better understand the process of overdeepening. Sedimentological analyses combined with downhole logging, analysis of biological remains, and state-of-the-art geochronological methods, will enable us to reconstruct the erosion and sedimentation history of the overdeepened troughs. This approach is expected to yield significant novel data quantifying the extent and timing of Middle and Late Pleistocene glaciations of the Alps. In a first phase, two sites were drilled in late 2021 into filled overdeepenings below the paleolobe of the Rhine Glacier, and both recovered a trough filling composed of multiphase glacial sequences. Fully cored Hole 5068_1_C reached a depth of 165m and recovered 10m molasse bedrock at the base. This hole will be used together with two flush holes (5068_1_A, 5068_1_B) for further geophysical cross-well experiments. Site 5068_2 reached a depth of 255m and bottomed out near the soft rock-bedrock contact. These two sites are complemented by three legacy drill sites that previously recovered filled overdeepenings below the more eastern Alpine Isar-Loisach, Salzach, and Traun paleoglacier lobes (5068_3, 5068_4, 5068_5). All analysis and interpretations of this DOVE Phase 1 will eventually lay the ground for an upcoming Phase 2 that will complete the pan-Alpine approach. This follow-up phase will investigate overdeepenings formerly occupied by paleoglacier lobes from the western and southern Alpine margins through drilling sites in France, Italy, and Slovenia. Available geological information and infrastructure make the Alps an ideal area to study overdeepened structures; however, the expected results of this study will not be restricted to the Alps. Such features are also known from other formerly glaciated mountain ranges, which are less studied than the Alps and more problematic with regards to drilling logistics. The results of this study will serve as textbook concepts to understand a full range of geological processes relevant to formerly glaciated areas all over our planet.

Organisation(s)

Institute of Geology

External Organisation(s)

University of Bern
Geological Survey of Slovenia (GeoZS)
Universite de Savoie
Leibniz Institute for Applied Geophysics (LIAG)
University of Freiburg
University of Geneva
Federal Institute for Geosciences and Natural Resources (BGR)
Nationale Genossenschaft für die Lagerung radioaktiver Abfälle (Nagra)
Dr. von Moos AG
Swiss Federal Institute of Aquatic Science and Technology (Eawag)
University of Salzburg
ETH Zurich
University of Leoben
University of Illinois at Urbana-Champaign
University of Natural Resources and Applied Life Sciences (BOKU)
Eidgenössisches Nuklearsicherheitsinspektorat (ENSI)
Geologische Bundesanstalt (GBA)
International Continental Scientific Drilling Program
Bayerisches Landesamt für Umwelt (LfU Bayern)
Landesamt für Geologie, Rohstoffe und Bergbau Baden-Württemberg (LGRB)
National Research Council Italy (CNR)

Type

Article

Journal

Scientific Drilling

Volume

31

Pages

51-70

No. of pages

20

ISSN

1816-8957

Publication date

10.2022

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Energy Engineering and Power Technology, Mechanical Engineering

Electronic version(s)

https://doi.org/10.5194/sd-31-51-2022 (Access: Open)
https://doi.org/10.3929/ethz-b-000582966 (Access: Open)