[meteorite-list] Re: Osmium ratios in irons and parent body size(s)

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Thu Apr 22 09:50:29 2004
Message-ID: <20020423170211.18364.qmail_at_web11607.mail.yahoo.com>

Once again, thanks, Bernd -

Some of these publications are recent, so there are
more than 2 people currently working with osmium and
its isotopes. The work does seem to be focused on
using osmium for dating, rather than using it as an
indicator of parent body size(s).

Recalling some earlier postings on clays (and thus
water) which have bee found in some meteorites, I am
still wondering exactly how "minor" the parent body
size(s) of meteorites were -

ep

--- Bernd Pauli HD
<bernd.pauli_at_lehrer1.rz.uni-karlsruhe.de> wrote:
> "E.P. Grondine" concluded:
>
> > If I understand the results of your database
> search,
> > what it amounts to is that exactly 2 people are
> > working on recovering the hard data which will
> allow
> > for the accurate estimate of parent body size(s).
>
> Hello E.P. and List,
>
> No, this is a misleading conclusion or a
> miscommunication. There is much
> more work that has been done especially with regard
> to the Re-Os method
> for formation-age determination. But with regard to
> its usefulness J.T.
> Wasson says on page 113 of "Wasson J.T. (1974)
> Meteorites, Classi-
> fication and Properties, Springer Verlag): "The long
> half-life and the
> fact that Re and Os are geochemically very coherent
> elements in
> meteorites limit the usefulness of this technique.
> HERR et al. (1961)
> determined a whole-rock Re-Os isochronic age for
> iron meteorites fo
> 4.0±0.8 Gyr."
>
> Best regards,
>
> Bernd
>
>
> Further useful references:
>
> HERR W.W. et al. (1961) Versuch zur Datierung von
> Eisenmeteoriten nach
> der Rhenium-Osmium Methode (Zeitschrift für
> Naturforschung 16a, 1961,
> pp. 1053-1058).
>
> MORGAN J. (1970) Anomalous rhenium isotopic ratio in
> the solar wind:
> Detection at the nanogram level, Nature
> 225,1037-1038).
>
> BIRCK J.L. (1991) The rhenium osmium chronometer:
> The iron
> meteorites revisited (Meteoritics 26-4, 1991, A318).
>
> PEGRAM W.J. et al. (1992) Osmium isotopic
> composition from
> oceanic basalts (Earth Plan. Sci. Lett. 111,
> 59-68).
>
> REISBERG L. et al. (1993) Os isotope systematics in
> ocean
> island basalts (Earth Plan.Sci.Lett. 120, 149-167).
>
> SHIREY S.B. et al. (1995) Carius tube digestion for
> low-blank
> rhenium-osmium analysis (Anal. Chem. 67,
> 2136-2141).
>
> SMOLIAR M.I. et al. (1995) Rhenium-osmium study of
> magmatic iron
> meteorites with low gallium abundances - groups IVA
> and IVB (abs.
> Meteoritics 30, 1995, 580).
>
> PAPANASTASSIOU D.A. et al. (1995) Rhenium-osmium in
> iron-nickel and
> phosphide: The possible determination of internal
> isochrons for iron
> meteorites (Meteoritics 30, 1995, 560).
>
> SHEN J.J. et al. (1996) Rhenium-osmium in pallasite
> and mesosiderite
> metal (abs. Meteoritics 31, 1996, A128).
>
> BIRCK J.L. et al. (1996) Rhenium-Osmium isotopes in
> meteorites
> (abs. Meteoritics 31, 1996, A014).
>
> SMOLIAR M.I. et al. (1997) Rhenium-osmium isochron
> for IA meteorites:
> Further refinement of the thenium-187 decay constant
> (Meteoritics 32-4,
> 1997, A122).
>
> CHEN J.H. et al. (1997) Rhenium-osmium fractionation
> and isotopic
> systematics in ordinary chondrites (Meteoritics
> 32-4, 1997, A027).
>
> J.L. BIRCK and C.J. ALLÈGRE (1998) Rhenium-187 /
> osmium-187 in
> iron meteorites and the strange origin of the
> Kodaïkanal meteorite
> (Meteoritics 33-4, 1998, 647).
>
> CHEN J.H. et al. (2000) Rhenium-osmium fractionation
> in group IIIAB iron
> meteorites (MAPS 35-5, 2000, Suppl., A039).
>
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Received on Tue 23 Apr 2002 01:02:11 PM PDT