THE ORIGIN OF THE TAVEYANNAZ SANDSTONE - ARGUMENTS FROM WHOLE-ROCK AND CLINOPYROXENE COMPOSITION

For the Taveyannaz sandstone of the Glarus Alps, whole-rock analyses a re presented and compared with data from the literature. Compositional changes due to detrital input and Alpine metamorphism can be estimate d bp optical and microprobe investigations. Major-element distribution s support a basaltic to basalt-andesitic composition for the volcanoge nic part of the sandstone. Magmatic clinopproxene composition and whol e-rod minor and trace element contents for which no increase nor decre ase by detrital input and metamorphism can be assumed, indicate a calc -alkaline character and a subduction-related volcanic are as the sourc e of the volcanics.