The Hadean Eon
When was it?
4.5 to 3.8 Billion years ago.
What was going on?
A lot, geologically. Nothing yet, biologically
More specifically, the earth was still forming -- during this period, a Mars-size body
probably collided with the Earth, forming the moon, and liquifying the early crust. Things
were probable pretty nasty. Thus the name, Hadean: "hades-like"
What were the continents like?
The continents, as we know them, didn't exist yet; the surface of the earth was still cooling.
What are sediments from the Hadean like?
I'm not clear on whether any sediments from the Hadean exist; Stanley refers to both the Hadean
and Archaean as the Archaean. If they do exist, they'd appear in cratons (very old, very stable parts
of the crust) just like Archaean rocks do.
What kind of life existed?
Nothing that we know of. The earliest known life appears in the next Eon, the Archaean.
Continue the tour to the Archaean
Note: Because of the lack of detail on the Hadean in Stanley, this is mostly from the
Nasa Classroom of the Future page
on the Precambrian