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