response 1 of 1:

May 10 16:43 UTC 2005

Probably not. It is thought that the early earth had a reducing admosphere
and crust (iron as Fe++, carbon and methane, etc). Some free oxygen would
hve been produced photochemically from water, but that would be consumed
in oxidizing other substances (which may be how the crust of Mars got to
be oxidized with much iron as Fe+++). Biological processes became the mass
producer of free oxygen - as a waste product - to create the current
oxygen-rich admosphere.