[meteorite-list] Meteoric water?

Mail actions: [ respond to this message ] [ mail a new topic ]
Contemporary messages sorted: [ by date ] [ by thread ] [ by subject ] [ by author ]

From: Howard Wu <freewu2000_at_meteoritecentral.com>
Date: Thu Apr 22 10:20:59 2004
Message-ID: <20030706200243.30227.qmail_at_web9307.mail.yahoo.com>

--0-1559789374-1057521763=:30130
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

Sounds alittle like Venus, earth without the moon

HWu

"Sterling K. Webb" <kelly_at_bhil.com> wrote:
Hi, Dave,

There is long standing debate as to the source of the Earth's waters.
Did all this H2O come from interior outgassing, primordial solar nebulae,
early heavy atmosphere, water delivery by comets? by meteorites? and so on.
One hears (on this list especially) references to the notion that the
Earth is essentially made from planetesimals which were essentially made
from asteroidal rubble which were made from... You get the idea: that you
can approximate the Earth by just piling up sufficient jillions of tons of
chondrites. This is a very common notion in cosmology, even today.
But if the Earth were nothing but compressed chondrites (and irons for
the core), it would have H2O oceans 200 to 300 kilometers deep, the
atmosphere would contain 100 to 200 bars of carbon dioxide, the carbon
content of the Earth would be 1000 times greater than it is, with a graphite
surface and diamonds everywhere! Doesn't sound familiar.
Everybody's geological textbook has a reference to a 1950 study by Rubly
that is the standard source for the notion that the Earth's water is
endogenous, but what he actually said is that all the proposed sources for
water only account for half of the Earth's water.
And, water is removed throughout geologic time. It is lost by a variety
of atmospheric mechanisms (like photo dissociation in the high atmosphere
and the escape of the hydrogen), so that however much water the Earth has
now, it had to have had more in the far past, which only makes the problem
worse.
Anyway, cosmological geologists are always looking for more water for
their model of the early Earth, so they've leaped on the "just a pile of
chondrites" model, with way too much water, and assumed that somehow 99% of
it was "lost." Nobody is very specific about just how you lose 99% of a
planet's water and dead silent about how you lose 99.9% of a planet's CARBON
for which there is no imagined removal mechanism whatsoever.
Assumptions like these have a way of just sort of sliding along from
decade to decade until everybody accepts them as true simply because they
don't think about them anymore.
Does that help? Or make it worse?

Sterling K. Webb
--------------------------------------------------------------------------------------

David Freeman wrote:

> Dear List, Geologic Associates;
> I came across the term "meteoric water" while reading up on pre-cambrian
> iron formations. Then, there was a relation to more modern/later times
> meteoric waters.
> Does this have any relationship to meteorites? Guess I am at maximum
> absorption level presently.
> Thank you in advance for any input,
> Dave Freeman
>
> _______

______________________________________________
Meteorite-list mailing list
Meteorite-list_at_meteoritecentral.com
http://www.pairlist.net/mailman/listinfo/meteorite-list

---------------------------------
Want to chat instantly with your online friends? Get the FREE Yahoo!Messenger
--0-1559789374-1057521763=:30130
Content-Type: text/html; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

<DIV>Sounds alittle like Venus, earth without the moon</DIV>
<DIV> </DIV>
<DIV>HWu "Sterling K. Webb" <kelly_at_bhil.com> wrote:</DIV>
<DIV>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid; WIDTH: 100%">Hi, Dave, There is long standing debate as to the source of the Earth's waters. Did all this H2O come from interior outgassing, primordial solar nebulae, early heavy atmosphere, water delivery by comets? by meteorites? and so on. One hears (on this list especially) references to the notion that the Earth is essentially made from planetesimals which were essentially made from asteroidal rubble which were made from... You get the idea: that you can approximate the Earth by just piling up sufficient jillions of tons of chondrites. This is a very common notion in cosmology, even today. But if the Earth were nothing but compressed chondrites (and irons for the core), it would have H2O oceans 200 to 300 kilometers deep, the atmosphere would contain 100 to 200 bars of carbon dioxide, the carbon content of the Earth would be 1000 times greater than it
is, with a graphite surface and diamonds everywhere! Doesn't sound familiar. Everybody's geological textbook has a reference to a 1950 study by Rubly that is the standard source for the notion that the Earth's water is endogenous, but what he actually said is that all the proposed sources for water only account for half of the Earth's water. And, water is removed throughout geologic time. It is lost by a variety of atmospheric mechanisms (like photo dissociation in the high atmosphere and the escape of the hydrogen), so that however much water the Earth has now, it had to have had more in the far past, which only makes the problem worse. Anyway, cosmological geologists are always looking for more water for their model of the early Earth, so they've leaped on the "just a pile of chondrites" model, with way too much water, and assumed that somehow 99% of it was "lost." Nobody is very specific about just how you lose 99% of a planet's water
and dead silent about how you lose 99.9% of a planet's CARBON for which there is no imagined removal mechanism whatsoever. Assumptions like these have a way of just sort of sliding along from decade to decade until everybody accepts them as true simply because they don't think about them anymore. Does that help? Or make it worse? Sterling K. Webb -------------------------------------------------------------------------------------- David Freeman wrote: > Dear List, Geologic Associates; > I came across the term "meteoric water" while reading up on pre-cambrian > iron formations. Then, there was a relation to more modern/later times > meteoric waters. > Does this have any relationship to meteorites? Guess I am at maximum > absorption level presently. > Thank you in advance for any input, > Dave Freeman > >
_______ ______________________________________________ Meteorite-list mailing list Meteorite-list_at_meteoritecentral.com http://www.pairlist.net/mailman/listinfo/meteorite-list</BLOCKQUOTE></DIV><hr size=1>Want to chat instantly with your online friends? <a href="http://uk.rd.yahoo.com/mail/tagline_messenger/*http://uk.messenger.yahoo.com/">Get the FREE Yahoo!
Messenger</a>
--0-1559789374-1057521763=:30130--
Received on Sun 06 Jul 2003 04:02:43 PM PDT

This message: [ Message body ]
Next message: GT40dawg_at_aol.com: "[meteorite-list] Fwd: analytical classification"
Previous message: PolandMET.com: "[meteorite-list] problems with emails :-("
In reply to: Sterling K. Webb: "[meteorite-list] Meteoric water?"
Next in thread: mafer: "[meteorite-list] Meteoric water?"
Reply: mafer: "[meteorite-list] Meteoric water?"

Mail actions: [ respond to this message ] [ mail a new topic ]
Contemporary messages sorted: [ by date ] [ by thread ] [ by subject ] [ by author ]

StumbleUpon

del.icio.us

Yahoo MyWeb