
Department of Geology – Portland State University [Geology Home]

G446 / G546 Meteorites

Winter Term 2012

MWF 10:00 - 10:50 am, CH S17

A. Ruzicka (+ big iron meteorites + muffin)

e-mail: ruzickaa@pdx.edu

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

Syllabus. (PDF file, posted 1-6-12; schedule revision 1-8-12)

Reading List. (Posted 1-6-12, revised 1-13-12 to indicate that all files are now available via D2L)

For the Bell et al. (1989) reading, I would skim the following: "Compositional meaning of Tholen Space", "Collisional and dynamical history", "Shapes". (Posted 1-20-12)

Here is a meteorite image gallery for some photos I obtained from the web. I could have put it up earlier but I didn't... (Posted 2-20-12)

There is a typo in the syllabus about the day of the final. It will occur on Tuesday Mar 20 8-9:50, not Thursday. (Posted 3-1-12)

For the Hutchison (2004) reading, focus on lunar and martian meteorites (Sec. 9.5 and 9.6), and also Fig. 9.3. (Posted 3-7-12)

As discussed in class, we will be starting and ending the final 30 minutes late. So the Final will be Tuesday Mar 20, 8:30-10:20. Melinda Hutson will be proctoring this exam as I will be in Houston for the Lunar and Planetary Science Conference. If you need to take a make-up exam, you will need to coordinate with me. (Posted 3-7-12)

Glossary and concepts