[meteorite-list] Olivine with Spinel Structure in Meteorites

From: Bernd Pauli HD <OliverPauli_at_meteoritecentral.com>
Date: Thu Apr 22 09:46:23 2004
Message-ID: <3AF3CD43.26DFE996_at_lehrer1.rz.uni-karlsruhe.de>

"E.L. Jones" schrieb:

> Is anyone aware of any research where the olivine in
> meteorites was found to exist in the spinel crystal structure?
>
> The reason I ask is that finding this spinel phase would indicate a
> very large body from which the meteorite was liberated/excavated.
> Olivine at great pressure (about 30 kilometers into the mantle,
> here on earth) shifts crystal structure to a more densely compacted
> form. Finding a spinel structure in a meteorite could give some
> indication of the size of the parent body.


Hello Elton and List,

Here are some references:

BINNS R.A. et al. (1969) Ringwoodite, natural (Mg, Fe)2SiO4
spinel in the Tenham meteorite (Nature 221, 943-944).

BINNS R.A. (1970) (Mg, Fe)2SiO4 spinel in a meteorite
(Phys.Earth Plan.Int. 3, 156-160).

FUDALI R.F. et al. (1975) Gobabeb, a new chondrite: The coexistence
of equilibrated silicates and unequilibrated spinels (Meteoritics 10,
1975, 31-41).

KRACHER A. et al. (1980) Ordinary chondrites:
The spinel puzzle (Meteoritics 15, 319-320).

MADON M. et al. (1980) Dislocations in spinel and garnet high pressure
polymorphs of olivine and pyroxene: Implication for mantle rheology
(Science 207, 66-68).

ENGI M. (1983) Equilibria involving A-Cr spinel: Mg-Fe exchange with
olivine. Experiments, thermodynamic analysis and consequences for
geothermometry (Amer. J. Sci. 283A, 29-71).

YABUKI H. et al. (1983) A petrologic microprobe survey of coexisting
olivines, pyroxenes and spinels in L- and LL- chondrites (Meteoritics
18, 426-428).

KORNACKI A.S. et al. (1984) Origin of spinel-rich chondrules and
inclusions in carbonaceous and ordinary chondrites (Proc.Lun.Plan.
Sci.Conf. 14th, B588-B596).

KORNACKI A.S. et al. (1985) Mineral chemistry and origin of spinel-rich
inclusions in the Allende CV3 chondrite (GCA 49, 1219-1237).

WLOTZKA F. (1985) Olivine-spinel and olivine-ilmenite thermometry
in chondrites of different petrologic type (abs. Lun.Plan. Sci. 16,
918-919).

McCOY T.J. et al. (1991) Spinel-bearing, Al-rich chondrules in two
chondrite finds from Roosevelt County, New Mexico: Indicators of
nebular and parent body processes (Meteoritics 26-4, 1991, 301-309).

KROT A.N. et al. (1992) Chrome-spinel inclusions in ordinary chondrites:
Mineralogy, chemistry and petrogenesis (Meteoritics 27-3, 1992, A245).

WEINBRUCH S. et al. (1994) Constraints on the thermal history of the
Allende parent body as derived from olivine-spinel thermometry and
Fe/Mg interdiffusion in olivine (GCA 58, 1019-1030).

LINGEMANN C.M. et al. (1994) Ringwoodite [= (Mg,Fe)2SiO4]
in shocked chondrites (abs. Meteoritics 29, 491-492):

Introduction: Since the discovery of ringwoodite in the meteorite
Tenham, further studies confirmed that this mineral occurs
preferentially in melt veins and melt pockets of highly shocked
L chondrites.

Ringwoodite is formed in chondrites at locations where localized melting
occurs by shock waves exceeding 50 GPa. The localized shock-pressure
and temperature concentrations are obviously favorable for the kinetics
of the olivine-spinel transition.

E. Zinner et al. (1995) A plagioclase-olivine-spinel-magnetite inclusion
from Maralinga (CK): Record of sequential condensation (abs. Meteoritics
30, 605).

LIERMANN H.P. et al. (1999) Thermodynamics and kinetics of Fe2+-Mg
exchange between spinel and orthopyroxene: Experimental determinations
and applications to cooling rates (MAPS 34-4, 1999, A 075).

GREENWOOD J.P. et al. (2000) A Karoonda conundrum: Primordial oxygen in
magnetite, olivine and iron-rich spinel in a metamorphosed CAI inclusion
(MAPS 35-5, 2000, Suppl., A063).


Best Regards,

Bernd
Received on Sat 05 May 2001 05:52:03 AM PDT