[Petwksp] Hmmm

[Jane Selverstone]

I would expect my students to be able do pretty well for andesite,  
tholeiite, alkali basalt, and granite. In particular, for these rock  
types, I would hope that they would know the plate tectonic setting,  
what the melt source(s) is/are, and whether the melts likely paused  
somewhere before reaching the site of final crystallization. In fact,  
I just caught a couple of my former petrology students in the hall,  
and confirmed that they could still recall this info. They also were  
able to tell me that alkali basalts generally represent smaller  
degrees of melting from a deeper source than tholeiites.  I doubt  
that many of them could simply look at a whole-rock analysis and know  
which rock it is, but I think that most of them would remember  
generally about things like whether the rock is silica saturated,  
high or low in alkalis, etc. I would also expect them to know that  
each of these rock types is part of a chemical spectrum, and none of  
them exist in isolation.

All of my students would fail outright on phonolite, anorthosite,  
kimberlite, and spilite -- though I would hope that they would know  
several different places to go for the relevant info on these rocks.  
I would rather spend my time on developing an understanding of  
petrologic processes in different plate tectonic settings rather than  
reviewing 50 different igneous rock types. And, let's not forget --  
we also need to leave time in the semester to study metamorphic rocks!

I strongly concur with Larry Mutti's comments that most students  
learn best by repeated exposure to material, in different contexts  
and at different levels. All of our courses should be intertwined to  
some degree to make sure that important subjects get revisited in  
other classes.

Jane

********************************************************
Professor Jane Selverstone
Department of Earth & Planetary Sciences
MSC03 2040
University of New Mexico
Albuquerque, NM 87131-1116 USA
Phone: 505-277-6528;  Fax: 505-277-8843
selver at unm.edu;   epswww.unm.edu/facstaff/selver


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://serc.carleton.edu/pipermail/petwksp/attachments/20060127/cc5e6fb1/attachment.html