After the formation of the Earth almost 4.6 billion years ago,
the Earth went through a long phase of cooling and differentiation.
But, this changed about 2.8 billion years ago, when the mantle was heated and
caused the most substantial formation of new crust in Earth history.
The crust was formed rapidly and was followed by widespread
hydrothermal activity and continental emergence.
This events, what has been named the Late Archean Superevent,
peaked probably around 2.7 billion yeas ago.
Scientists have suggested that the emergence of continents caused
the development of large shelf areas around the continents, which
received nutrients through weathering of the terrestrial areas.
As a result, it is believed that the amount of microscopic organisms including
cyanobacteria did increase significantly during the latest Archean.
So is there any visual evidence of this event?
Yes, luckily there is.
For instance did the first continental flood basalts appear during this event for
just 2.7 billion years ago
in Pilbara, Australia together with shallow marine and lake carbonates.
We have now seen different types of evidence for the development of
prokaryotic life during the Archean. In the next lesson we'll look at how the Proterozoic rise
in oxygen content was linked with the rise in eukaryote evolution and diversity,
and also have a closer look at some of the prokaryotes and
eukaryotes that typified the Proterozoic.
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