ALPINE METAMORPHISM IN THE NORTH HELVETIC FLYSCH OF THE GLARUS-ALPS, SWITZERLAND

Mineral assemblages of the Taveyannaz sandstone, illite crystallinitie s, vitrinite reflectance data, and fluid inclusion homogenization temp eratures (T-h) are presented for the Wageten slice and the North Helve tic flysch in the Glarus Alps. The Wageten slice reached zeolite facie s (laumontite, corrensite), characterized by a diagenetic illite cryst allinity, R(max) less than or equal to 2%, and higher hydrocarbons-bea ring fluid inclusions with T-h = 160-190 degrees C. Within the norther n part of the North Helvetic flysch (Lochsiten locality) uppermost dia genetic illites coincide with R(max) = 3-4%, and methane-bearing fluid inclusions with T-h = 230 degrees C. Prehnite-pumpellyite/pumpellyite -actinolite facies, upper anchizone/lowermost epizone, R(max) > 8%, wa ter-rich fluid inclusions with trapping temperatures of 270-300 degree s C are found in the southernmost outcrops of the North Helvetic flysc h. Transported metamorphism along the Glarus overthrust is confirmed b y the data presented, and a post-metamorphic displacement of approxima tely 10 km can be estimated. The Wageten slice must have been separate d from the North Helvetic flysch before the onset of metamorphism in t he Infrahelvetic units. This supports a Helvetic rather than a Subhelv etic position for this tectonic unit.