Project Details
Projekt
Investigating Early-Stage Quaternary Overdeepening in Oberschwaben (EQuOs)
Applicant
Dr. Lukas Gegg
Subject Area
Geology
Term
since 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 517980590
Overdeepenings are closed basins incised into the bedrock by subglacial erosion and following ice retreat, they become infilled with water and sediments. The sedimentary fillings, some of which are composed of multiple cycles representing separate glaciations, are archives of enormous scientific value. Investigation of overdeepenings and their infills is the key to understanding the processes and drivers of subglacial erosion, the timing and sequence of past glaciations, and thus their cumulated impact on landscape and topography.This proposal acts as a complement and an expansion to the project “Drilling Overdeepened Alpine Valleys” (DOVE) of the International Continental Scientific Drilling Program (ICDP). It is centred around two already acquired and available drill cores from the Lake Constance area in southwestern Germany (Oberschwaben), which recovered the infills and the underlying bedrock of two separate overdeepenings in high quality. What is special about these overdeepenings is their exceptional stratigraphic position: Preliminary results show that both drill cores comprise complex successions that presumably reach back to the early Middle and Early Pleistocene, respectively, a time span that is currently only poorly constrained, and not covered by ICDP DOVE.The analysis and interpretation of the drill cores will be conducted mainly by a PhD student, and is subdivided into four work packages: LOG: detailed sedimentological logging and imaging, including X-ray computed tomography scanning, complemented by standard methods such as grain size and gravel petrographic analyses. TECH: characterisation of geotechnical properties in order to identify glacially derived material, e.g. via liquid and plastic limits, and ice contact-deposits, e.g. via preconsolidation pressure. CHRON: establishment of a chronostratigraphy using a combination of luminescence dating, terrestrial cosmogenic nuclide dating, and the sediments’ remanent magnetic polarisations. REGIO: integration of the newly acquired data in the overarching geological context, and parallelisation with existing records of the Alpine foreland, new results from other DOVE-sites as well as distal sediment records such as that of the Upper Rhine Graben.The PhD student will benefit from energetic support by the entire project group at the University of Freiburg that is proficient in Quaternary and glacial geology, and experienced in the chosen methods. Further support stems from the ICDP DOVE scientific team and other selected, partly international, collaborators. The outcomes of this project will increase our understanding of the (sub-)glacial environment, of the currently incomplete regional glaciation history, and of the question how our present-day landscape has been shaped over the course of the Quaternary.
DFG Programme
Infrastructure Priority Programmes
International Connection
Switzerland
Co-Investigator
Professor Dr. Frank Preusser
Cooperation Partner
Professor Dr. Flavio Anselmetti
