Proterozoic

The Proterozoic ( ) is the third of the four geologic eons of Earth's history, spanning the time interval from to Ma, and is the longest eon of Earth's geologic time scale. It is preceded by the Archean and followed by the Phanerozoic, and is the most recent part of the Precambrian "supereon".

thumb|Reconstruction of Rodinia at 900 million years ago, using modern images to illustrate where today's recognisable continents were at the time. Rodinia (from the Russian родина, rodina, meaning "motherland, birthplace") was a Mesoproterozoic and Neoproterozoic supercontinent that assembled 1.26–0.90 billion years ago (Ga) and broke up 750–633 million years ago (Ma). were probably the first to recognise a Precambrian supercontinent, which they named "Pangaea I". It was renamed "Rodinia" by , who also were the first to produce a plate reconstruction and propose a temporal framework for the s

thumb|Pannotia was centred on the South Pole, hence its name. Pannotia (from Greek: pan-, "all", -nótos, "south"; meaning "all southern land"), also known as the Vendian supercontinent, Greater Gondwana, and the Pan-African supercontinent, was a relatively short-lived Neoproterozoic supercontinent that formed at the end of the Precambrian during the Pan-African orogeny (650–500 Ma), during the Cryogenian period, and broke apart 560 Ma with the opening of the Iapetus Ocean, in the late Ediacaran and early Cambrian. Pannotia formed when Laurentia was located adjacent to the two major South Ameri

worldwide glaciation episodes during the Cryogenian Period of the Neoproterozoic Era

thumb|upright=1.35|Baltica (in white, at the centre of the image, with outline of present-day Europe for reference) Baltica is a paleocontinent that formed in the Paleoproterozoic and now constitutes northwestern Eurasia, or Europe north of the Trans-European Suture Zone and west of the Ural Mountains. The thick core of Baltica, the East European Craton, is more than three billion years old and formed part of the Rodinia supercontinent at 1 .

Anorthosite () is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present.

ancient supercontinent (2.5–1.5 Gya) in the Paleoproterozoic Era

historic ocean

ancient supercontinent

thumb|Atlantica at about 2 Ga. Archean cratons in grey. Atlantica (; Atlantika) is an ancient continent that formed during the Proterozoic about (two billion years ago, Ga) from various 2 Ga cratons located in what are now West Africa and eastern South America. The name, introduced by John Rogers in 1996, was chosen because the parts of the ancient continent are now located on opposite sides of the South Atlantic Ocean.

Arctica or Arctida is a hypothetical ancient continent which formed approximately 2.565 billion years ago in the Neoarchean era. It was made of Archaean cratons, including the Siberian Craton, with its Anabar/Aldan shields in Siberia, and the Slave, Wyoming, Superior, and North Atlantic cratons in North America. Arctica was named by because the Arctic Ocean formed by the separation of the North American and Siberian cratons. Russian geologists writing in English call the continent "Arctida" since it was given that name in 1987, alternatively the Hyperborean craton, in reference to the hyp

ancient ocean that existed from the latest Ediacaran to the Carboniferous

small Precambrian ocean between Baltica and the Siberian continent

Earth history between 1.8 and 0.8 billion years ago, characterized by tectonic stability, climatic stasis, and a slow biological evolution with very low oxygen levels and no evidence of glaciation

stage in the geological timescale named after the Urals

extinction event marking the end of the Proterozoic eon and the beginning of the Phanerozoic eon (as well as the Cambrian era)

Suggested composition of the ocean in the middle to late Proterozoic