ICDP Project DOVE (Drilling Overdeepened Alpine Valleys): First results from the Basadingen Borehole

The panalpine project "DOVE" (Drilling Overdeepened Alpine Valleys), co-funded by the International Continental Scientific Drilling Program (ICDP), is drilling a series of overdeepened glacial troughs around the Alps that were formed by subglacial erosion during past glaciations. The sedimentary fill of these troughs, consisting of multiple stacked and nested glacial sequences, provides the best archives of when and where glaciers reached the Alpine forelands. The combined data from all DOVE sites comprising synchronous or asynchronous ice advances and ice extents in the different regions, will eventually provide a critical database to evaluate the various patterns in glacial-interglacial paleoclimates and landscape evolution back to the Mid-Pleistocene. One of the DOVE sites drilled the overdeepened Basadingen Trough, located in Northern Switzerland, within the extents of several Middle-Late Pleistocene foreland glaciations of a lobe of the Rheine Glacier. The trough is a narrow, ca. 250-300 m deep structure that runs SSE-NNW, forming a so-far poorly understood, old overdeepened valley system that connected the present-day Thur Valley with the Rhine Valley – a connection that does not exist in the present surface morphology and that was probably only active during the Middle Pleistocene. New high-resolution 2-D seismic displays a detailed seismic stratigraphy with several depositional sequences, indicating that the valley fill consists of deposits from multiple glaciations, making the Basadingen Trough an ideal target for DOVE. We aim to establish a chronostratigraphic and sedimentological model to identify and understand the older glaciations that affected the Basadingen Trough and the Northern Alpine foreland in general.