Geological cross section southern Siberia
The Riphean is a stage or age of the geologic timescale from 1,400 to 800 million years ago. The name Riphean is used in the Proterozoic stratigraphy of the Siberian Craton in Russia. It was also used in a number of older international geologic timescales but is in the most recent timescales of the ICS replaced by the Ectasian, Stenian and Tonian periods of the Neo- and Mesoproterozoic eras.
The word 'Riphean' comes from the ancient Riphean Mountains, sometimes identified with the Ural Mountains.