ICDP Proposal Page

Drilling Overdeepened Alpine Valleys (DOVE)

Europe, Austria, France, Italy, Slovenia, Switzerland, Alpes

revised full-proposal: ICDP-2016/04
for the funding-period starting 2016-01-15

by Flavio Anselmetti, Frank Preusser, Milos Bavec, Christian Crouzet, Markus Fiebig, Gerald Gabriel, Cesare Ravazzi

Abstract

The sedimentary infill of glacially overdeepened valleys (i.e. excavated structures below the fluvial base level) are, together with glacial geomorphology, the best-preserved (but underexplored) direct archives of extents and ages of past glaciations in and around mountain ranges. DOVE intends to recover a number of sediment cores from glacially overdeepened structures at several complementing locations within the Alps and their foreland. While substantial matching funds have already been granted or are envisaged, we are here asking for financial support from ICDP for drilling seven sites in six different countries, spread over three fiscal years. One completed and four additional sites, which will be drilled independently from DOVE decisions, eventually will form a twelve-site DOVE backbone. The cores will be investigated with regard to several aspects of environmental dynamics during the Quaternary, with focus on the glaciation, vegetation, and landscape history. For example, the geometry of overdeepened structures will be investigated using different geophysical approaches (e.g. seismic surveys) and will help to better understand the process of overdeepening. Sedimentological analyses in combination with downhole logging, investigation of biological remains, thermochronometry and using state-of-the-art geochronological methods will allow to reconstruct the filling and erosion history of the troughs. We expect significant and novel data relating to the extent and timing of the past Alpine glaciations during the Middle-to-Late Quaternary glacial-interglacial cycles. While we take advantage of the available geological information and infrastructure in the Alps, the results of this study will not be restricted to this area. The Alps provide the ideal area to study overdeepened structures, features also known from other mountain ranges and areas formerly covered by ice sheets, which are less studied than the Alps and more problematic with regards to logistics for drilling. The results of this study will serve as textbook examples for understanding a full suite of geological processes relevant for formerly glaciated areas all over the world. Moreover, DOVE will tie together scientist from several countries and set a turning point boosting international collaboration in the Alpine realm. Besides the scientific goals, this proposal also addresses a number of applied objectives such as groundwater resources, geothermal energy production, and seismic hazard assessment. By drilling in highly populated areas, this initiative will gain major attention by local authorities, communities and the media. Hence, DOVE fully considers the goals of the new science plan of ICDP, flagging societal relevance as major objective while offering numerous outreach opportunities.

Scientific Objectives

Scientific objectives 1) The timing of the onset, the number, and the extent of Quaternary glaciations of the Alps,
2) The impact of atmospheric circulation patterns on ice build-up along and across the Alps,
3) How mountain ranges and their foreland have been shaped by repetitive glaciations, and 4) The impact of multiple glaciations on Alpine ecosystems. Approaches applied to solve these questions will be: a) Geophysical surveys to describe the geometry of overdeepening, b) Downhole logging, sedimentological, and geochemical analyses to characterize the deposits, c) Combination of different approaches (biostratigraphy, luminescence dating, cosmogenic nuclide dating, magnetostratigraphy, and eventually tephrastratigraphy) to establish the chronological framework, d) Correlation of all analysis across the entire DOVE sites, i.e. across and along the Alpine chain, to obtain the overregional comparison. d) Thermochronometry for quantifying the rates and timing of mountain topographic development, e) Biological proxy to reconstruct the history of climate and mountain life in the Alps. The results from the above approaches will be cross-checked with the outcome of modelling both glacial erosion and past climate circulation patterns. Additionally, we will screen for subsurface biosphere and eventually carry out further investigations in this direction. Applied aspects addressed beside the scientific topics are:
1) The potential of overdeepened structures as groundwater resources,
2) Seismic hazard and site effects in Quaternary valleys,
3) Potential of the Quaternary valley fills for shallow geothermal applications,
4) Improving the interpretation of geophysical data from overdeepened valleys.

Keywords

DOVE, European alps, Glacial-interglacial cycles, ICDP-2016/04, Landscape evolution, Paleoclimate, Water

Location

Europe, Austria, France, Italy, Slovenia, Switzerland, Alpes: 45.47411, 6.05461