robertmaas

In another newsgroup some questions arose which we thought might be
better answered by experts frequenting these newsgroups. See the
following URL for critical point in that other thread:
http://www.google.com/groups?selm=c7778g%24a3m%241%40darwin.ediacara.org
The general topic is natural processes early in Earth's
history that might have produced large amounts of
certain chemicals useful for respiration by early life
and pre-life.

Summary of specific questions that arose there:

Mostly for sci.geo.geology,alt.sci.planetary:
- During formation of Earth by ac***ulating
planetesimals, both regular ones that were in Solar
orbit, and specific debris from the Mars-size collision
that swiped out a big chunk of the Earth's early mantle
to form a thick ring around Earth part of which formed
the Moon: As iron settled toward the center of Earth
and silicates floated toward the surface, at what rate
would H2 gas liberated from the iron etc. as it changed
temperature and pressure have seeped upward for
hundreds of millions of years after the Earth got cool
enough for the first oceans to form?

Mostly for sci.chem:
- What happens when a smaller iron-nickel meteor
strikes an atmosphere of N2, CO2, and H2O. Would you
will get a rain-out of a complex mix of ferrocyanides
and nickel carbonyls, along with some finely divided
nickel metal?

Mostly for sci.chem:
- When a large carbonaceous asteroid/comet hits early
Earth, would the central portion release much of its
oxygen, leaving mostly unoxidized carbon? Then later as
it was exposed to the early CO2 and H2O atmosphere, and
disturbed by volcanic heat, would the material react
with the atmosphere to produce a lot of carbon
monoxide?

john

I prefer the construct that all planets and their satellites began
as gas giants. The gas giants nearest the Sun lost their hydrogen-
helium atmospheres to solar wind as illustrated by HD 209458b
http://hubblesite.org/newscenter/newsdesk/archive/releases/2003/08/text/
Loss of H-He lowered the atmospheric pressure thus allowing the
escape of primordial gases from the planetary interior as
illustrated by deepsea volcanos:
http://www.pmel.noaa.gov/vents/chemistry/images/vents2.gif
Each of the escaping gases: hydrogen, helium, neon and methane has
solar isotopic composition as illustrated by helium:
http://hil.whoi.edu/geol/geol.html
Addition of ammonia to the hydrogen, methane and hot water of the
deepsea volcano recreates the Urey-Miller soup, which is now
enriched by the rest of the 100 elements. John Curtis