4th Swiss Geoscience Meeting, Bern 2006 An angular unconformity below the Wildflysch nappe in the Glarus Alps- Observations from the area around the Landesplattenberg in Engi.

lowed a pre-existing Miocene age erosional angular unconformity (Fig. 1; German: "Reliefüberschiebung"). Field work carried out in 2005 and 2006 in the area around the Landesplattenberg in Engi (Kanton Glarus) reveals that this angular unconformity may be found at the base of the Glarus Wildflysch nappe***, which lies as a roughly 5 to 100 m thick, more or less continuous sheet below the Glarus Thrust. The Landesplattenberg in Engi is an abandoned mine from which slates were were extracted, mainly for roofing. There is a small museum and there are guided tours through the mine shafts. The mine is dug in the Lower Oligocene Engi Slates (Engi Dachschiefer), the youngest member of the Matt Formation, North Helvetic Flysch. A geological map and tectonic profiles 1:5'000 of the area around the Landes-plattenberg were made in the framework of a diploma thesis (Gasser 2006). A detailed structural analysis was carried out, thin sections were made and studied. Even though the Engi Slates are lithologically monotonous, structural profiles could be constructed with relative ease due to the presence of a 5 to 10 m thick turbiditic sandstone member. The turbiditic sandstones also provided unequivocal top-botto