English: “Graupensand”, a sandy deposit, overlain by “Austernnagelfluh”, a conglomerate, at the former quarry at Riedern am Sand (near Waldshut, Germany and Schaffhausen, Switzerland). Both units are part of the fill of the late Early Miocene “Graupensandrinne” (something like an “incised valley”). The 10 km wide paleo-valley at the northwestern margin of the North Alpine Fore-land Basin has already been filled up in Miocene times and is now morphologically invisible. While the “Graupensand” (Grimmelfingen beds) is present throughout the “Graupensandrinne”, the “Austernnagelfluh” only occurs in its southwestern part, where it interfingers with the “Graupensand”.