- The Orosirian Period ( /ˌɒroʊˈsɪəriən/; Ancient Greek: ὀροσειρά, romanized: oroseirá, meaning “mountain range”) is the third geologic period in the Paleoproterozoic Era and lasted from 2050 Mya to 1800 Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically.
- Statherian (Wikipedia)
The Statherian Period ( /stəˈθɪəriən/; Ancient Greek: σταθερός, romanized: statherós, meaning “stable, firm”) is the final geologic period in the Paleoproterozoic Era and lasted from 1800 Mya to 1600 Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically.
- Paleoproterozoic (Wikipedia)
The Paleoproterozoic Era (also spelled Palaeoproterozoic) is the first of the three sub-divisions (eras) of the Proterozoic eon, and also the longest era of the Earth’s geological history, spanning from 2,500 to 1,600 million years ago (2.5–1.6 Ga). It is further subdivided into four geologic periods, namely the Siderian, Rhyacian, Orosirian and Statherian.
- Rhyacian (Wikipedia)
The Rhyacian Period ( /raɪˈeɪsi.ən/; Ancient Greek: ῥύαξ, romanized: rhýax, meaning “stream of lava”) is the second geologic period in the Paleoproterozoic Era and lasted from 2300 Mya to 2050 Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically.