G446 / G546 Meteorites
Coming Winter Term 2010
MWF 11:30 - 12:35 am, CH 69
A. Ruzicka (+ iron meteorites + muffin)
e-mail: ruzickaa@pdx.edu
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Images of two very different meteorites, the Murchison (CM2) chondrite at left, and the Henbury (IIIAB) iron at right.
Murchison was derived from an asteroid that never melted,
and which was rich in water and organic
materials. These organic materials provide evidence for pre-biotic
synthesis of organic molecules,
which appear to have formed originally in the interstellar medium.
Bright spots in the meteorite are chondrules and refractory inclusions;
fusion crust is the
brown coating at left.
In contrast, Henbury was derived from the core of a melted
asteroid.
The core cooled very slowly (roughly 1 degree C per million years!)
owing to its deep burial in the
parent body. This slow cooling enabled the low-nickel metal
alloy mineral kamacite to exsolve from the
high-nickel metal alloy mineral taenite, producing the intergrowth
pattern (Widmanstatten texture) obvious
in the image.
Course information
Glossary and concepts
Other reference materials
- Cascadia Meteorite Laboratory website. This explains how to identify meteorites, and gives other information.
- Updated meteorite classification diagram (140 kb JPG image from http://ifp.uni-muenster.de/ap/classification.phtml ). (Posted 1-9-08)
Homework assignments
Score distributions and answer keys
Last Updated: November 15, 2009