The diagram contains all names recommended by SKS at group, subgroup, formation, member and bed levels. Member and bed names in italics represent informal units. The ages and age boundaries of the units are indicated in accordance with existing data, but are admittedly schematic. Possible diachronous boundaries are drawn straight unless reliable data can document the diachronism. The indicated major hiati are also drawn schematically and do not claim any precision concerning their age range. Minor hiati are omitted. Vertical lines between formations may represent interfingering relationships.