The Archean Earth was hotter (from impacts and more radioactive decay). A more vigorous mantle convection probably kept most plates smaller than today.

1
The Archean Earth was hotter (from impacts and
more radioactive decay). A more vigorous mantle
convection probably kept most plates smaller than
today.
(left 3 billion years ago)
2
Earliest atmosphere formed by degassing (gases
spewed out by volcanoes) would have been rich in
N2, H2O, CO2. Earliest crust would have been
basaltic (close to average mantle composition),
Mg-rich and Si-poor.
3
Meteorite impacts may have vapourized the early
atmosphere many times, sterilizing the Earth.
But comets brought water and possibly many
organic chemicals which are the building blocks
of life.
http//www.sciam.com/1999/0799issue/0799bernsteinb
ox1.html
4
Where are the Archean rocks (black patches)
5
Acasta gneiss, in Nunavut a metamorphosed
granite.
Grains of zircon (ZrSiO4, upper right), a tough
mineral rich in U, Th, were dated in 1998, as
4.03 billion yrs old.
6
Much of the Canadian Shield is Archean (yellow on
map), and it hosts rich metallic mineral
resources.
7
(Australia)
(Greenland)
(Nunavut, Canada)
8
The O18/O16 ratio of oldest zircons may indicate
that liquid water was present earlier than we
thought.