Riphean stage
Encyclopedia
The Riphean is a stage or age of the geologic timescale from . The name Riphean is used in the Proterozoic
Proterozoic
The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life"...

 stratigraphy
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....

 of the Siberian Craton in Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. It was also used in a number of older international geologic timescales but is in the most recent timescales of the ICS
International Commission on Stratigraphy
The International Commission on Stratigraphy , sometimes referred to by the unofficial "International Stratigraphic Commission" is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphy, geological, and geochronological matters on a global...

 replaced by the Ectasian
Ectasian
The Ectasian is the second geologic period in the Mesoproterozoic Era and lasted from 1400 Mya ago to 1200 Mya...

, Stenian
Stenian
The Stenian is the final geologic period in the Mesoproterozoic Era and lasted from 1200 Mya to 1000 Mya . Instead of being based on stratigraphy, these dates are defined chronometrically...

  and Tonian
Tonian
The Tonian is the first geologic period in the Neoproterozoic Era and lasted from 1000 Mya to 850 Mya...

 periods of the Neo-
Neoproterozoic
The Neoproterozoic Era is the unit of geologic time from 1,000 to 542.0 ± 1.0 million years ago. The terminal Era of the formal Proterozoic Eon , it is further subdivided into the Tonian, Cryogenian, and Ediacaran Periods...

 and Mesoproterozoic
Mesoproterozoic
The Mesoproterozoic Era is a geologic era that occurred between 1600 Ma and 1000 Ma . The Mesoproterozoic was the first period of Earth's history with a respectable geological record. Continents existed in the Paleoproterozoic, but we know little about them...

 eras.

The word 'Riphean' comes from the ancient Riphean Mountains
Riphean Mountains
The Riphean Mountains are mountains mentioned by authors of classical antiquity , but whose location is unknown....

, sometimes identified with the Ural Mountains
Ural Mountains
The Ural Mountains , or simply the Urals, are a mountain range that runs approximately from north to south through western Russia, from the coast of the Arctic Ocean to the Ural River and northwestern Kazakhstan. Their eastern side is usually considered the natural boundary between Europe and Asia...

.
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