2D Reflection Seismic Exploration and Provisory Interpretation of Overdeepened Quaternary Valleys around the Nagra Siting Regions Zürich Nordost and Nördlich Lägern

pdf NAB 18-22 2D Reflection Seismic Exploration and Provisory Interpretation of Overdeepened Quaternary Valleys around the Nagra Siting Regions Zürich Nordost and Nördlich Lägern(188.94 MB)

In the context of the sectoral plan "Sachplan geologische Tiefenlager" (SGT) Nagra is currently investigating three sites 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.

As part of the QAU project Nagra acquired a series of high resolution 2D-seismic profiles in winter of 2016/2017. The majority of the profiles (16 out of 23) aimed at verifying and characterising glacially overdeepened Quaternary valleys and troughs within and around the siting regions "Zürich Nordost" (ZNO) and "Nördlich Lägern" (NL) and thereby updating the investigation area's Base Quaternary model.

This report summarises the planning, acquisition, processing and first interpretation of these 16 profiles (Fig. 1-1). The presented seismic interpretation is meant to serve the planning of Quarternary exploration boreholes in the next phase of the QAU project. As the findings derived from these boreholes will likely require certain interpretation adjustments, the current version is considered provisory.