Kluftmessungen im Gelände und ihre Bedeutung für die Bestimmung des tektonischen Spannungsfeldes in der Schweiz

[摘要] An intensive program of measurements of the orientationof joints in the field in Switzerland wasundertaken in the Cantons of Graubünden, St. Gallen, Schwyz, Uri, Zürich, Zug, Aargau and Berne.For every «region», comprising 2–8 outcrops, theaverage orientation of the joint-parallelepiped wascalculated by means of an electronic Computer basedon a function-minimization program. If it is assumedthat the steeply-dipping Joint surfaces have been produced by the present-day triaxial stress field accordingto the Mohr-Anderson theory of faulting, theorientation of the latter can be calculated. Thus, thenet of present-day stress trajectories for Switzerlandcan be drawn. It turns out that the average orientation of the greatest compression in the region investigatedis N 60^°W. This agrees well with in-situ stressdeterminations by Gysel in the Sonnenbergtunnelnear Lucerne (N 76.5^°W) and by Greiner in southernGermany (N 28^°–50^°W). Converseiy, the hypothesisthat most joints visible on fresh outcrops are due tothe present-day tectonic Stresses and that the latteris homogeneous over extended areas, is thereby confirmed.

[学科分类] 自然科学（综合）