Arbeitsbericht NAB 19-05
Quaternary Borehole QBO Neuhausen (QNEU) Quaternary Borehole – Data Report
In the context of the sectoral plan "Sachplan geologische Tiefenlager" (SGT) Nagra is currently investigating three sites (Jura Ost, Nördlich Lägern, Zürich Nordost) in northern Switzerland to potentially host repositories for radioactive waste. The field exploration project "Quartäruntersuchungen" (QAU) is dedicated to the characterisation of Quaternary deposits within and around these siting regions to further constrain scenarios of their geological long-term evolution. The investigations support the reconstruction of Quaternary landscape evolution.
The borehole (Quartärbohrung, QBO) at Neuhausen (QBO Neuhausen / QNEU, Tab. 1) is part of Nagra’s Quaternary investigation program (QAU; compare Nagra 2017). The QNEU drill site (Fig. 1 and 2) is located very close to a previous destructive drilling (11-NS-AZ-34; Dr. Heinrich Jäckli AG 2012; Fig. 2) and was chosen to further characterize and sample the valley fill of the Neuhauserwald Channel (Neuhauserwald-Rinne) as well as verify its reported depth. The borehole QNEU was conducted from 21.11.2018-01.02.2019 using a combination of Düsterloh hammer drilling and wire-line drilling with a triple-tube core-barrel, i.e. with a plastic core liner.
This report covers the request for a documentation of the authorized works on-site (UVEK 2018, Dispositiv 5.11) and documents also the core description and first lab analyses (UVEK 2018, Dispositiv 5.12). The work has been carried out according to the work program (Arbeitsprogramm, Nagra 2018) and this report corresponds to the data report announced there.
In this report, we present core images, sedimentological descriptions, and geophysical measurements of the cores, all of which were acquired at the University of Bern. Additionally, a report on geophysical borehole logging by BLM Gesellschaft für Bohrlochmessungen mbH and L. Keller (roXplore gmbh; responsible for quality control) and a technical drilling report by Fretus AG edited by P. Hinterholzer-Reisegger (Nagra) are presented in appendices H and I, respectively. This report is the basis for planning further core analysis and later interpretation in the larger geological context.