Today, COSC-2 passed 800 m depth. Even more exciting is that we drilled into a different geological unit at c. 775 m. At about this depth, the seismic and magnetotelluric site investigations indicated the shallowest alum shale at the top of an about 500 m thick imbricate unit that overlies the basal Caledonian décollement. We encountered an until now continuous unit of penetratively deformed black shales with lenses of calcareous shale or limestone. The coming days will show what other lithologies the imbricate unit is composed of. With the entry into the black shales, on-site sampling and preservation of shale from above, in and below the décollement commenced for rock mechanic investigations on the nature of the deformation in this regional scale overthrust.