4.7 Billion Years Ago to 540 Million Years
From the accretion of primal stellar dust to the early
development of multi-celled bacteria, the PreCambrian covers the
early beginnings of Earth. The PreCambrian spans the formation of the planet to
end of the Proterozoic, comprising nearly 87% of the geologic
timescale. The three divisions (eons) of the PreCambrian
SuperEon are the following:
- The solar system, the Earth and the Moon are formed
- The development of the Earth's core, crust and mantle and the predominant
elements and minerals occurred during the tumultuous early
beginnings of this planet.
- Elements such as carbon, iron and oxygen have key
functions in future discussions of mass extinctions and
the formation of continents.
- Their formation are keys to the foundations of
life on Earth
- The earth’s magnetic poles emerge.
- Earth develops an atmosphere.
- An oxygen/nitrogen atmosphere was only the last step
in a changing world .
- Earth’s oceans and continental plates were formed.
- The oceans circulatory patterns dictate climate.
- Early cratons and the major minerals that are contained within the continents are formed.
- The breakup of the supercontinent Rodinia produced six large continents.
- The formation of Gondwana, forming 650 million years ago from the smaller continents of Africa, South America, India, Australia and Antarctica.
- Climatic forces such as glaciations, solar radiation and reflection (albedo) as mechanisms regulated the temperatures on Earth.
- The Varangian glaciations gave way to the warming of the Vendian Period.
- Snowball Earth - 750 million years ago the entire
Earth was encompassed in a glacier.
- Anaerobic Life – early life forms that existed without the presence of oxygen.
- Cyanobacteria - the most primitive organisms known.
- Ediacaran Fauna – the first large multi-celled creatures.