[meteorite-list] Asteroid Color Clans

From: John Divelbiss <j.divelbiss_at_meteoritecentral.com>
Date: Thu Apr 22 10:06:14 2004
Message-ID: <002501c286ca$e62cb2c0$7a005a0c_at_0m824>

EP,

Your scenario is along the lines I was thinking, but the evidence to support
it seems limited at this time. In time we will learn more I'm sure.

As you and others may have noticed, I do not mind exposing my ignorance on a
given subject. Doing so opens up the possiblilty of someone else teaching me
something new, or as you have done...provoke more thinking. Especially on a
subject like this that does not have clear cut answers at this time. Even a
low IQ guy like me can help all of us to think more about a given subject,
which hopefully leads to bringing enlightenment to all of us. My favorite
line in my work is that "I'm dumber than a rock (or meteorite) until I get
it". That applies to rocks from space.

Thanx EP for adding to the discussion. Bernd...what say about all this?

John

PS I still think mesosiderites are just impact melts...different process
(molten collision versus solid collision) maybe, but still an impact formed
texture of stone and metal. Why label it a stoney-iron??? Looks like
Portales Valley and some IMB's should be called stoney iron too. Hmmmm...
there I go again exposing myself to the world.

----- Original Message -----
From: "E.P. Grondine" <epgrondine_at_yahoo.com>
To: <meteorite-list_at_meteoritecentral.com>
Sent: Thursday, November 07, 2002 6:26 PM
Subject: Re: [meteorite-list] Asteroid Color Clans


> Hi all -
>
> It seems to me that instead of the meteorite classes
> being tied to one particular asteroid, it is more
> likely that ultimately the classes of meteorites (and
> some sub-classes not yet separated out) will be tied
> to classes of asteroids. In other words, in this
> particular case the source may not necessarily Vesta,
> but a Vesta-like asteroid.
>
> If there are classes of asteroids, and my guessis that
> it will turn out that there are, then you get into the
> differentiation problem and the problem of parent body
> size.
>
> Wild stuff, but that's how I think this is going to
> play out. Hopefully someday soon we'll probably see a
> telescope actually placed within the "asteroid belt"
> and we'll know the true state with certainty.
>
> ep
>
>
> --- John Divelbiss <j.divelbiss_at_worldnet.att.net>
> wrote:
> > Hi Al,
> >
> > Great stuff Al. As always, thank you for responding
> > to my question and
> > comments. You guys are going to force me back into
> > the books to see what I
> > read, but obviously didn't learn.
> >
> > As I remember it, the evidence with Vesta has to do
> > with the large "gouge"
> > in it's side that shows different levels of crust
> > (eucrite) and sub crust
> > (diogenite). This leads to another challenge or
> > question, "if we think all
> > or most of HED's come from Vesta, then why do they
> > look so different from
> > each other?". Some eucrites are white or grey, while
> > others are a shade of
> > light brown/yellow. The differences in diogenites
> > are even greater. Is the
> > new olivine diogentite thought to be from Vesta
> > also?
> >
> > My answer would be "they sure could be". My
> > experience in finding plutonic
> > rocks here on earth is that the same area of
> > exposure searched can have a
> > wide variety (in appearance) of same type type rock.
> > Some are more rich in
> > one mineral than another...but for the most part
> > still made up of the same
> > ingredients. Temperature and pressure of the magma
> > at one location versus
> > another precipitates out minerals at different
> > rates. Also the makeup of the
> > magma then changes as it losses more of one element
> > than others, changing
> > the resulting rock formation mineral ratios. I
> > think I answered my own
> > question, but I'M WAY OVER MY HEAD HERE!!!
> >
> > HELP.....John
> >
> >
> >
> > ----- Original Message -----
> > From: "almitt" <almitt_at_kconline.com>
> > To: "John Divelbiss" <j.divelbiss_at_worldnet.att.net>
> > Cc: "Bernd Pauli HD"
> > <bernd.pauli_at_lehrer.uni-karlsruhe.de>; "Meteorite
> > List"
> > <meteorite-list_at_meteoritecentral.com>
> > Sent: Tuesday, November 05, 2002 1:23 AM
> > Subject: Re: [meteorite-list] Asteroid Color Clans
> >
> >
> > > Hi John,
> > >
> > > I'll take a stab at this but Bernd really has
> > great resources for
> > answering this no
> > > doubt better than I can. The topic that Bernd had
> > started was on asteroid
> > color clans
> > > and that at least 90 percent of asteroids are
> > associated with families
> > (from
> > > collisions in the past). No doubt the Vesta HED's
> > are from chunks broken
> > off from
> > > Vesta in an impact and that have made their way
> > into an orbit that upon
> > further impact
> > > has allowed meteoroids to end up in some of the
> > kirkwood gaps where they
> > can be
> > > purbatrated into Earth crossing orbits. Yes they
> > are from other sources
> > but they
> > > originated from the same source or asteroid. No
> > doubt this is true for the
> > other
> > > related asteroid family groups and again the color
> > clans that they are
> > beginning to
> > > piece together with the new research.
> > >
> > > I don't know if we can say for sure or not if a
> > certain meteorite is from
> > a particular
> > > asteroid chunk or fragment but there is very
> > strong evidence to show the
> > HED's are
> > > indeed from Vesta and also a strong link of the H
> > type chondrites to
> > asteroid Hebe. I
> > > don't think there is much doubt about the Mars
> > type meteorites (SNC's) are
> > from Mars
> > > and the Lunar meteorites are from the moon as we
> > have been there and have
> > material to
> > > compare to. With the color clans coming into play
> > we can at least say that
> > certain
> > > meteorites are from certain families now.
> > >
> > > On a related note Mar's moon Phobos is very
> > similar to the CV3's like
> > Allende but
> > > there are also many other asteroids out there with
> > that spectral match
> > (could it be
> > > the same clan?) I have always thought with the
> > larger crater I see in the
> > photos taken
> > > by NASA that Phobos was a good candidate for that
> > source material.
> > >
> > > Another question or comment. Perhaps some of the
> > meteorites of different
> > classes
> > > sample the same asteroid (or family, clan). We
> > could have iron meteorites,
> > pallasites
> > > and chondrites or achondrites all from the same
> > parent body but we are
> > looking at
> > > different depths of material all from the same
> > parent body or asteroid
> > family clan.
> > > This is no doubt true of the meteorites we have
> > from Vesta and shows
> > material from
> > > different depths. My best!
> > >
> > > --AL
> > >
> > > John Divelbiss wrote:
> > >
> > > > Hi Al, Rob, Bernd and others,
> > > >
> > > > I think it is wonderful to think we can match
> > types with asteroids that
> > are
> > > > labeled and watched.
> > > >
> > > > I have a question. Is it safe to say that what
> > we are doing is matching
> > > > spectrums of types with those same specturms for
> > a given asteroid, but
> > not
> > > > necessarily committing to say that is probably
> > from that asteroid. In
> > other
> > > > words, their maybe(must be) several to hundreds
> > of a given type asteroid
> > out
> > > > there. And that one LL4 could come from one
> > rock, and another from a
> > > > different rock with the same spectrum on the
> > opposite side of the belt.
> > I
> > > > maybe stating the obvious, but for instance I so
> > often read that an HED
> > is
> > > > probably from the asteroid Vesta, when in truth
> > it maybe from another
> > one.
> > >
> > >
> >
> >
> > ______________________________________________
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> >
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Received on Thu 07 Nov 2002 09:02:30 PM PST