Hiatus concretions are distinguished by their stratigraphic history of exhumation, exposure and reburial. They are found where submarine erosion has concentrated early diagenetic concretions as lag surfaces by washing away surrounding fine-grained sediments (Zaton 2010). Their significance for stratigraphy, sedimentology and paleontology was first noted by Voigt (1968) who referred to them as Hiatus-Konkretionen.