Two of the largest known impact events on Earth occurred during the Orosirian. Early in the period, 2023 Mya, a large asteroid collision created the Vredefort impact structure. The event that created the Sudbury Basin structure occurred near the end of the period, 1850 Mya.

citation

Wikipedia contributors. (2023, August 15). Orosirian. In Wikipedia, The Free Encyclopedia. Retrieved February 7, 2024, from https://en.wikipedia.org/w/index.php?title=Orosirian&oldid=1170442244

Orosirian (Wikipedia) 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.