compositional relationships between meteorites …pschool/pub/21coeps/school/2007/...between...
TRANSCRIPT
![Page 1: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/1.jpg)
Compositional relationships between meteorites and planets
I
Kevin RighterNASA Johnson Space Center
![Page 2: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/2.jpg)
Accretion models for terrestrial planetsCan we make planets from meteorites?
What are the outstanding problems?
![Page 3: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/3.jpg)
Overview1st lecture – Thursday
a) Starting materials and conditionsBuilding blocksPhysical and timing constraintsThermal constraints
b) How chondrites are modifiedProcesses (melting, fractionation, residues)Controlling variables – T, P, fO2, water
c) Key parameters for defining bulk compositions
d) Example 1: Vesta
![Page 4: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/4.jpg)
Building blocks
After Ringwood (1977) From Krot et al. (2003)
![Page 5: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/5.jpg)
Building blocks
From Krot et al. (2003)
![Page 6: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/6.jpg)
Stages in the accretion process
dust
planetesimals embryos
From Nichols (2006)
![Page 7: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/7.jpg)
Timescales of accretion process
Hierarchy of materials mass timeframe (yrs)
a) gas/dust to planetesimals 1012-1018 g ~105
b) planetesimals to embryos 1026-1027 g ~106
c) embryos to proto/planets 1027-1028 g ~107
![Page 8: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/8.jpg)
Embryos to solar systems
From Chambers (2003)Results of N-body simulations
![Page 9: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/9.jpg)
How chondrites are modifiedLow temperature and aqueous alteration processes – covered by Adrian and Sasha
Shock processes – Tom Sharp
Igneous processes- Melting- Fractionation and accumulation- Residua
-What evidence is there in the meteorite collections? [compare to Earth]
![Page 10: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/10.jpg)
MeltingTerrestrial basalts and residues
Basalt (melt)
Harzburgite (residue)Peridotite (unmelted mantle) 3 mm
1 mm
![Page 11: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/11.jpg)
Melting on the Earth has many potential mechanisms – current day
• Stress relief• Convective rise• Frictional heating (plate
tectonics)• Compositional change
(diffusion, volatile addition)• Radioactive heat
What about asteroids and other planets?
![Page 12: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/12.jpg)
MeltingMeteoritic basalts – eucrites, shergottites, angrites
![Page 13: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/13.jpg)
Melting residuaMeteoritic residua – ureilites, lodranites, acapulcoites
ureiliteUngrouped ultramafic achondrite
![Page 14: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/14.jpg)
Melting residuaMeteoritic residua – ureilites, lodranites, acapulcoites
Meteoritic examples have added complication of metal– metal can be trapped (dihedral angles)
HED/Vesta
from Righter (2003)
![Page 15: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/15.jpg)
Fractionation and accumulationTerrestrial cumulate – Stillwater Complex, Montana
Cumulate olivine and chromite
![Page 16: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/16.jpg)
Fractionation and accumulationMeteoritic cumulates – eucrites, nahklites, pallasites
Pallasite – olivine orthocumulate
Cumulate eucrite - adcumulate
Nakhlite – clinopyroxene mesocumulate
![Page 17: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/17.jpg)
There is clear evidence for melting in the meteorite record, so what factors are involved?
• Temperature (radioactivity, impacts, gravity)• Pressure• Oxygen fugacity (or pressure)• Water (and other volatiles)
![Page 18: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/18.jpg)
Thermal constraints and heat sourcesRadioactivity: 26Al, 60Fe, other short lived
40K, 238U, 235U, 232Th – long lived
From Rubie et al. (2007)
![Page 19: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/19.jpg)
Thermal constraints and heat sourcesImpacts – material can achieve 10,000 K
From Rubie et al. (2007)
∆T = 6000K(γ/0.1)(M/Me)2/3
From energy balance of kinetic and gravitational potential energyin merged object
![Page 20: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/20.jpg)
Thermal constraints and heat sourcesGravitational – once core formation starts it is an
“energetic cascade”
From Rubie et al. (2007)
Moving metal from the base of a magma ocean through the solid lower mantle to the core will result in a situation with lower potential energy. Energy derived through such a process can cause temperature changes of several hundred to a few thousand Kε= thickness of metal
layer
β = initial core radius
![Page 21: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/21.jpg)
TemperatureHeating models in comparison to
basaltic phase equilibria
From Ghosh et al. (2006)
![Page 22: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/22.jpg)
PressurePressure to core-mantle boundary in planets
and mineralogy change with depth
From Righter (2003)
![Page 23: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/23.jpg)
PressureUnderstanding of melting at high pressures
and temperatures is very limited
From Asahara et al. (2004)
![Page 24: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/24.jpg)
High pressure experimentsNASA-JSC laboratory
0.3 to 3.0 GPa(10 to 100 km depth)
1200 to 2500 ˚C
Used to study
-Mantle melting-Chondrite phase equilibria-Metal-silicate equilibrium (core formation)-Diffusion of Ru, Ir, Ga, Co, in FeNi metal
![Page 25: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/25.jpg)
Experimental techniques
![Page 26: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/26.jpg)
High pressure experimentsPressure: 3.0 to 30.0 GPaTemperature: up to 2800 °C
Used to study
-Chondrite phase equilibria (H, E)-Metal-silicate equilibrium (core formation)
Au, Pd, Re, Os
![Page 27: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/27.jpg)
Multi-anvil assemblies
Pressure module and 6 wedges
Octahedral pressure medium and
tungsten carbide cubes
![Page 28: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/28.jpg)
Experimental techniques
![Page 29: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/29.jpg)
Pressure calibration by phase bracketing
![Page 30: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/30.jpg)
Run products can be cut and polished and analyzed using EMPA, SIMS, LA-ICP-MS, SEM, etc.
1.5 GPa, 1800 ˚C, basalt and metal 1 mm
![Page 31: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/31.jpg)
High PT phase diagram for Richardton H5
From Lisa Danielson, Melanie Channon, Josh Garber
![Page 32: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/32.jpg)
High PT phase equilibria of enstatite chondrites
From Sophie Berthet
Ph.D. thesis research
![Page 33: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/33.jpg)
In situ phase equilibria – Argonne National Lab
![Page 34: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/34.jpg)
In situ phase equilibria – Argonne National Lab
From Danielson et al. (2006)
![Page 35: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/35.jpg)
Oxygen fugacity (fO2)
2Fe + O2 = 2FeO(solid) (gas) (solid)
1) Fugacity is really just pressure(ideal gas has a fugacity = pressure;
non-ideal gas has fugacity ≠ pressure)
2) The above equilibrium is called a “buffer” – will stay at the same value of fO2, regardless of
how much Fe or FeO is added
![Page 36: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/36.jpg)
Oxygen fugacityAbsolute, relative
From Righter (2003)
Fe-FeO
Iron-wüstiteor
“IW”
![Page 37: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/37.jpg)
Oxygen fugacity – reduced exampleSi + Fe + 3/2 O2 = FeSiO3
Aubrite or “enstatite achondrite” ALH 84011
metal metal gas orthopyroxene
![Page 38: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/38.jpg)
Oxygen fugacity – oxidized example2 Fe3O4 + ½ O2 = 3 Fe2O3
CK chondrite EET 90007From Righter and Neff (2007)
magnetite gas hematite
![Page 39: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/39.jpg)
Oxygen fugacity
Oxygen fugacity varies within
chondritegroups by 15
orders of magnitude
From Righter and Neff (2007)
![Page 40: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/40.jpg)
Oxygen fugacityP, fO2, and C-CO-CO2 system
Graphite can buffer fO2Below metal stability field at low pressures.
And above metal stability at high pressure.
![Page 41: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/41.jpg)
Water Depresses liquidus and solidus
From Hyndman (1986) From Abe et al. (2000)
![Page 42: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/42.jpg)
Key parameters in defining bulk composition
Oxygen isotopes
From Righter(2007)
Despite uncertainties about the origin of oxygen isotopic variation (nucleosynthesis, mass-independent fractionation, or self-shielding), oxygen can be used toconstrain source materials
![Page 43: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/43.jpg)
Key parameters in defining bulk composition
Oxygen isotopes
From Righter (2007)
Differences between Mars, Earth-Moon, angrites and eucrites are small but measurable
![Page 44: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/44.jpg)
Key parameters in defining bulk composition
major elements
From Drake and Righter (2002)
![Page 45: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/45.jpg)
Key parameters in defining bulk composition
D/H and noble gases for volatile-bearing planets
From Drake and Righter (2002)
![Page 46: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/46.jpg)
Key parameters in defining bulk composition
D/H and noble gases for volatile-bearing planets
From Owen and Bar-nun (2000)
![Page 47: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/47.jpg)
Example 1: 4 Vesta (HED parent body)
Enhanced from Hubble Space Telescope imaging – 1995 and 1996
![Page 48: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/48.jpg)
Introduction: What are the HED meteorites ?
howarditeeucritediogenite
![Page 49: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/49.jpg)
Vesta/HED link and history
McCord et al. (1970) Gaffey (1997)
![Page 50: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/50.jpg)
Vesta/HED problems
- multiple heating?- core formed?
- if partially melted, where are the residues?
Should be a relatively simple case: low pressure and dry
![Page 51: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/51.jpg)
Vesta: oxygen isotopes
Mixtures that satisfyO isotopes
H-CVL-CVLL,L,H-CO
Boesenberg and Delaney (1997)
![Page 52: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/52.jpg)
Fe/Mn relationsMixtures that satisfy Fe/Mn
Goodrich and Delaney (2000)
![Page 53: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/53.jpg)
Fe/Mn relationsMixtures that satisfy Fe/Mn
Goodrich and Delaney (2000)
![Page 54: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/54.jpg)
Formation model for HED/VestaCan explain
diogenites, later eucrites and
later mixing of two to form howardites
Satisfies O and Fe/Mn
From Righter and Drake (1997)
![Page 55: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/55.jpg)
Major element evolution diagramEquilibrium with later fractionation
From Righter and Drake (1997)
![Page 56: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/56.jpg)
Outstanding problemsVolatile element depletion
Vesta/HED is volatile element depleted, but so are all of the terrestrial planets so far, compared to chondrites
Mars
Earth Moon
HED
angrites
From O’Neill and Palme (2003)
![Page 57: Compositional relationships between meteorites …pschool/pub/21coeps/SCHOOL/2007/...between meteorites and planets I Kevin Righter NASA Johnson Space Center Accretion models for terrestrial](https://reader031.vdocuments.site/reader031/viewer/2022013022/5f6e097fd5ede40ac408ec35/html5/thumbnails/57.jpg)
DAWN mission May be able to resolve some of these outstanding questions
C/MR2
Vesta mantle compositionVolatile elementsTh, K, U