Riphean (stage)

Geological cross-section of southern Siberia, showing Riphean rocks buried under at least 2 km of younger rocks

The Riphean is a stage or age of the geologic timescale from 1,600 to 650 million years ago. The name Riphean is used in the Proterozoic stratigraphy of Russia and the Fennoscandian Shield in Finland.[1] It was also used in a number of older international geologic timescales but, in the most recent timescales of the ICS, it is replaced by the Calymmian, Ectasian, Stenian, Tonian and Cryogenian periods of the Neoproterozoic and Mesoproterozoic eras.

The word 'Riphean' comes from the ancient Riphean Mountains, sometimes identified with the Ural Mountains.

The Riphean has been divided by geologists into the Early Riphean (1600–1400 Ma), Middle Riphean (1400–1000 Ma) and Late Riphean (1000–650 Ma) subdivisions.[1][2]

See also

References

  1. 1 2 Paulamäki, S. and Kuivamäki, A. (2006). Depositional History and Tectonic Regimes within and in the Margins of the Fennoscandian Shield During the Last 1300 Million Years (PDF). Posiva Oy.
  2. ↑ Rundqvist, D.V. and Mitrofanov, F.P. (editors) (1993). Precambrian Geology of the USSR. p. 181.
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