Assise

An assise (from the Fr., derived from Latin assidere, 'to sit beside'), is a geological term for two or more beds or strata of rock united by the occurrence of the same characteristic species or genera. In the hierarchy of stratigraphic units, an assise lies between a stage (or sub-stage) and a stratum. An assise (from the Fr., derived from Latin assidere, 'to sit beside'), is a geological term for two or more beds or strata of rock united by the occurrence of the same characteristic species or genera. In the hierarchy of stratigraphic units, an assise lies between a stage (or sub-stage) and a stratum.