The Err Nappe is a Lower Austroalpine tectonic unit confined to an area northwest of the Engadine Fault between Albulapass and Julierpass where it overlies the Carungas Slice. Towards the south it is separated from the Julier Nappe (Bernina Nappe Complex) by a multiply deformed synclinorium, the so-called “Samedan Zone”.