
Department of Geology – Portland State University [Geology Home]

G446 / G546 Meteorites

Winter Term 2008

MWF 11:30 - 12:35 am, CH 69

A. Ruzicka (+ 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 (posted 12-21-07)

Reading list (posted 12-21-07)

Accessing items on reserve (posted 12-21-07)

I have placed a copy of the readings on 2-hour Reserve in my mailbox in CH17, in case you want to photocopy this rather going to the library. Please have consideration for your fellow students and put this packet back in my mailbox when you are done with it. I'll leave the packet in my mailbox for the next week or so. (posted 1-8-07)

What to focus on in the Bell et al. (1989) paper: Read but skim the following sections-- Compositional Meaning of Tholen Space, Collisonal and Dynamical History, Shapes. (posted 1-16-08)

The MacPherson et al. (1988) paper has a lot of detail, with the risk that you will not see the forest for all of the trees. For example, the authors describe details about refractory inclusions in different chondrite groups, with the most important aspect of this being what is similar rather than different. Use the problem set as a guide to what you should understand. (posted 1-25-08)

Revised schedule. (posted 2-13-08)

Grades have been submitted (see final scores and grades link below). I will be leaving a box outside my door that has your graded final exams and the remaining homeworks. Each person's materials will be contained in a separate packet, so you need only look for your name to pick up your work. I hope you had fun in the class (even though you probably were cursing me more than once while working on the many homeworks) and learned a lot. I hope to see you in other upcoming classes I teach (e.g., Astrogeology, Geochemistry). (posted 3-22-08)

Glossary and concepts