The Tonium is a period of Earth's history. Its beginning is geochronological recognized before about 1,000 million years ago and its end before about 850 million years ago. The Tonium part of the Proterozoic, the third ( penultimate ) eon of Earth's history,. It forms within the recent era of the Proterozoic, the Neoproterozoic, the first ( earliest ) period. The Tonium following the Stenium, the last period of Mesoproterozoikums, and is detached from the Cryogenium.
The name is derived from gr Tonas, expand '. He alludes to the further expansion of the ancient cratons.
Events during the Tonium
The outstanding geological event in the Tonium was the existence of a single supercontinent, Rodinia, which, however, already fell apart at the end of Toniums again. In Rodinia almost all cratons were included ( the old continental nuclei of the present continents ). At the same analogy existed a single gigantic ocean, Mirovia called that encircled the mega- continent Rodinia.
In Tonium mountain building processes took place, but these are only partially known or explored. The beginning of the period coincides with the end of the Grenville orogeny, a major orogenic phase which occurred during the formation Rodinias and were formed during their inter alia mountain ranges in what is now eastern North America and in today's Indian sub-continent. During the Toniums even the slightly less significant Edmund orogeny (ca. 920-850 mya ) was held, inter alia, formed the parts of present-day Australia.