EntityQ403523· pop 18· linked from 113 articlessystemSign in to saveidealized composite unit of the geologic record representing the totality of rock strata laid down during a certain period of the geologic time scaleConnectionsgeologic time scaleEntitystageEntityseriesEntityWayback MachineEntitydigital object identifierEntityunit of measurementEntityCretaceousEntityPaleozoicEntityMesozoicEntityCenozoicEntityCarboniferousEntityOrdovicianEntityQuaternaryEntitystratigraphyEntityProterozoicEntityPhanerozoicEntityPaleogeneEntityNeogeneEntityMioceneEntityEoceneEntityCategoriesChronostratigraphyErathemsGeochronologyGeological periodsGeological unitsGeologic time scalesGeology terminologyStratigraphy