Two new formation names are proposed—Omihi Formation (older) and Waikari Formation (younger). The Omihi Formation consists of five members: Berrydale Greensand, Gorries Creek Greensand, Tekoa Tuffs, Flaxdown limestone, and a redefined Weka Pass Stone. The Flaxdown limestone stratigraphically succeeds the Tekoa Tuffs in north-west North Canterbury. Elsewhere the members grade laterally into one another. Hence the names apply rather to the facies variants of the Omihi Formation.