Friday, 23 December 2011

Planet Earth - The Stenian Period - The jigsaw on Boxing Day

The Stenian Period ran from 1,200 to 1,000 million years ago and was the last period of the Mesoproterozoic Era. The name derives from the Greek word for narrow polymetamorphic (many rocks that are changed by heat and pressure) bands created within the rock.

The Rodinian supercontinent starts its main construction time of this supercontinent spanned from 1,100 to 780 million years despite some of the material having been already established in the last period, Ectasian. The name Rodinia comes from the Russian for "birth". The evidence for this supercontinent is found within the orogenies of the time (Dalslandian in Europe, the previously mentioned Grenville in North America and the Uralian in Siberia). With geological evidence, it is thought that Rodinia was centred south of the equator. Rodinia is thought to have comprised of the Amazonian Craton, Australia, the Congo Craton, Eastern Antarctica,  the Eastern European Craton, India, the Kalahari Cratonthe North American Craton, the Rio de la Plata and Sao Francisco Craton, the West African Craton. So, basically a supercontinent made up of jigsaw parts of huge cratons. 

After the break up of the continent around 780 to 750 million years ago, the fragments became part of the supercontinent Pangaea.

Next time - The Neoproterozoic Era and the Tonian Period

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