Upload
lenard-kelley-ryan
View
225
Download
2
Tags:
Embed Size (px)
Citation preview
Universitätzu Köln Meteorites and
the early solar system.
Dominik Hezel
D. C. Hezel: Meteorites and the early solar system
General Remarks
Meteorites allow precise determinations of processes in the inner
solar nebula (< ~4 AU) during a time span of about 30 Ma.
Reprocessing of presolar material (ISM), i.e. formation of the
primitive material found in meteorites occurred during ~ 2 Ma.
It is not known when this reprocessing occurred during
protoplanetary disk evolution.
D. C. Hezel: Meteorites and the early solar system
Chondrules =
formerly small melt droplets
Chondrule Ø: ~20 – 2 000 µm
500 µm
D. C. Hezel: Meteorites and the early solar system
Acfer 209
D. C. Hezel: Meteorites and the early solar system
D. C. Hezel: Meteorites and the early solar system
0 20 40 60-60 -40 -20
26Mg* [ppm]
asteroidalresidues
asteroidalmelts
after: Bizzarro et al. 2005; Baker & Bizzarro 2005
av. solar system(Earth)
high Al/Mglow Al/Mg
Al-Mg decay system:
26Al → 26Mg
T1/2 = 0.74 Ma
D. C. Hezel: Meteorites and the early solar system
0 0.2 0.4 0.6-0.4 -0.2
182W* [ppm]
av. solar system(chondrites)
iron meteorites
Earth
Mars
1.7
eucrites
2.9
data from: Kleine et al. 2002, 2005
metal-poor(high Hf/W)
metal-rich(low Hf/W)
Hf-W decay system:
182Hf → 182W
T1/2 = 9 Ma
D. C. Hezel: Meteorites and the early solar system
condensed CAI(image: A. Pack)
Ca, Al-rich phases
condensend rim
CAIs – Ca, Al-rich inclusions
„Type II“ REE-pattern that can only
be achieved during condensation.
D. C. Hezel: Meteorites and the early solar system
Ni-map
Image: Th. Schönbeck
Meibom et al. 1999
D. C. Hezel: Meteorites and the early solar system
dec
reas
ing
tem
per
atu
re
3. pyroxene Mg2[Si2O6]
Px
1. olivine Mg2[SiO4]
Ol
4. quartz SiO2
SiO2
2. metal Fe93Ni7
FeNi
D. C. Hezel: Meteorites and the early solar system
Hezel et al. 2003
from: Davis & Richter 2005
Fe-Ni-metal
Enstatite – MgSiO3
Forsterite – Mg2SiO4
Gehlenite Ca2Al2SiO7
Hibonite CaAl12SiO19
CorundumAl2O3
Anorthite
Temperature (K)
Fra
ctio
n C
I ch
ond
riti
c co
mp
osit
ion
con
den
sed
Cpx
Albite
D. C. Hezel: Meteorites and the early solar system
Spl
D. C. Hezel: Meteorites and the early solar system
Petaev & Wood 1998
D. C. Hezel: Meteorites and the early solar system
Chondrule bulk compositions
Hezel et al. 2006
~1440°C ~1700°C
D. C. Hezel: Meteorites and the early solar system
porphyritic chondrule Barred olivine chondrule
olivine
pyroxene
glass
metal
glass olivine
D. C. Hezel: Meteorites and the early solar system
Con
noll
y et
al.
1998
olivineglass
olivineglass
D. C. Hezel: Meteorites and the early solar system
Desch & Connolly 2002
Chondrules formed by flash heating with peak temperatures >2000 K.
The nature of the chondrule forming event is unknown, the recent
favorite mechanisms are shock waves.
D. C. Hezel: Meteorites and the early solar system
image: Klerner 2001
Allende
150 µm
0
5
10
15
20
25
30
35
0 5 10 15 20 25 30
Si [wt%]
Mg
[wt%
]D. C. Hezel: Meteorites and the early solar system
Hez
el &
Kie
ßwet
ter
in p
rep.
Efremovka
Chondrule-matrix complementarity requires a
common reservoir for both components.
matrix
chondrules
enstatite(intermediate Mg)
forsterite(high Mg)
solarMg/Si-ratio
solarMg-, Si-composition
D. C. Hezel: Meteorites and the early solar system
Bizzarro et al. 2004
-0.5 0 0.5 1 1.5
[Ma]
CAIs
POP
PO
BO
Al-rich
condensed CAIs
chondrules
age obtained from decay: 26Al → 26Mg
D. C. Hezel: Meteorites and the early solar system
schematic model of the formation of solid matter in the early solar system
Thank you forThank you for
your attentionyour attention