Universität zu Köln Meteorites and the early solar system. Dominik Hezel.

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.

Chondrules =

formerly small melt droplets

Chondrule Ø: ~20 – 2 000 µm

500 µm


Acfer 209


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


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


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.


Ni-map

Image: Th. Schönbeck

Meibom et al. 1999


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


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


Spl


Petaev & Wood 1998


Chondrule bulk compositions

Hezel et al. 2006

~1440°C ~1700°C


porphyritic chondrule Barred olivine chondrule

olivine

pyroxene

glass

metal

glass olivine


Con

noll

y et

al.

1998

olivineglass

olivineglass


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.


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


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


schematic model of the formation of solid matter in the early solar system

Thank you forThank you for

your attentionyour attention

Universität zu Köln Meteorites and the early solar system. Dominik Hezel.

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