Eoarchean

The Eoarchaikum is a geological era ( era ) in the aeon of the Archean. It is within the Archean, the second eon of Earth's history, the earliest of four eras Represents the Eoarchaikum (from the Greek eos = " dawn " ) follows about 4,000 million years immediately following the first eon of Earth's history, the Hadean, in which the Planet Earth was formed. The Eoarchaikum ends before 3,600 million years ago with the transition to Paläoarchaikum.

Geology

It is characteristic of the Eoarchaikum that the earth has in this age the first time a solid crust that is still constantly breaks in many places and is crossed by glowing lava flows. At the beginning of Eoarchaikums is a period of very heavy Asteroid impacts in the inner solar system, the Late Heavy Bombardment.

The Eoarchaikum is the earliest phase of our planet, are obtained from the rock formations. The largest of the so-called Isua gneiss is mya on the southwest coast of Greenland with an age of about 3,800. Since the discovery of Acasta gneisses in 1989 in the northwestern Canadian Shield, which were later dated to 4,030 mya, these are considered the oldest preserved rocks. In 2008, however, the rocks were discovered in Nuvvuagittuq greenstone belt in northern Quebec in Canada that have been dated to about 4,280 mya. You are still the subject of current research.

It is now accepted that in Eoarchaikum already existed oceans. The atmosphere of the era was completely different from today's, and was probably a reducing.

Biology

An outstanding development of Eoarchaikums is the formation of the earliest forms of organic life or preforms in the form of prokaryotes ( simple single-celled organisms without a nucleus ). Particular in the oldest known rock strata from Greenland (see above) found carbon isotopes is attributed to an organic origin. The earliest stromatolites are Eoarchaikum - created - or possibly until the following era, the Paläoarchaikum.

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