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The Hadean marks the beginning of Earth which formed
4.6 billion years ago. It’s the very first Eon on the
Geologic Time Scale.
Not much is left from the Hadean. The
oldest known mineral is a zircon that was
found in Australia. It’s 4.2 to 4.4 billion
years old.
The atmosphere
was so thick with
poisonous gases, it
partially blocked the
weaker light of the
sun. The sky was
darker than it is
today and life was
unsustainable.
The Earth was very
hot. Volcanism was
at an all-time high.
Protocrust of
ultramafic and mafic
rock was created
then re-melted.
Volcanic outgassing
was releasing water
and oceans were
forming.
Bombardment from meteors
and asteroids was very
heavy during the Hadean.
They provided heat and
water to young Earth .
The Moon was
formed during the
Early Hadean. It
might have been
created by a huge
impact with our
planet. It was much
closer to Earth and
still hot from it’s
formation.
Sources
Illustration by Chesley Bonestell
http://www.antiquark.com/weblog/2005_02_01_antiquark_archive.html
http://www.dailygalaxy.com/my_weblog/2007/08/earths-oldest-o.html
http://forum.ourdarkskies.com/index.php?showtopic=19877
http://dailyapple.blogspot.com/2007/01/apple-215-moon-and-life-onearth.html
http://www.newsback.com/forums/news-242-maybe-the-hadean-eonwasnt-so-bad.html
Sources
http://utubelaughter.blogspot.com/2007/08/worlds-oldest-diamondsunearthed-in.html
Dr. Kathleen Devaney, Lecture, Geology 1302
lab Exercises for Historical Geology, Deborah Caskey, Vicki Harder
The Changing Earth: Exploring Geology & Evolution, Monroe / Wicander