Fig. 4From: Evaluating igneous sources of the Taveyannaz formation in the Central Alps by detrital zircon U–Pb age dating and geochemistryRock slab and thin section photographs (plain and polarised light) of phreato-volcanic pebbles in the Glarus B Taveyannaz Fm. (Ruchi sandstone after Siegenthaler 1974). a 17GL03 (type 1); b 17GL06 (type 2); c 17GL07 (Type 3); d 17GL05 (pebble in pebble, type 2 in type 3)Back to article page