Exploratory borehole Schafisheim: investigation report. Appendix volume

In 1980, Nagra launched an extensive geological investigation programme covering an area of some 1.200 km2 in Northern Switzerland. The aim of the programme was to collect the geological information necessary for assessing the suitability of the crystalline basement as a disposal medium for high-level radioactive waste. The Schafisheim borehole was the fourth, and the most southerly, in the deep drilling programme. The aim of the Schafisheim borehole was to drill through the sedimentary overburden and around 500 m deep into the crystalline basement. A wide range of investigations was carried out in the borehole itself, as well as on drillcores and water samples. This report is a summary of the most important results obtained during the course of the programme at Schafisheim. The series of investigation reports for the deep boreholes is structured in such a way that cross-comparisons can be made between the results and datasets for the different locations. The conclusions to be drawn from the data will be reserved for a final synthesis report. Detailed documentation of individual experiments is provided in Nagra's Technical Report series. (author) figs., tabs. refs