Dave Hirsch's Research

I currently have two main areas of research: Regional metamorphic petrology of the Pacific Northwest, and studies of metamorphic crystallization. The former typically involve fieldwork, electron microprobe analysis, radiometric dating and thermodynamic modeling. The latter typically involve less fieldwork, but more analytical work, and are conceptually more demanding.

• Projects for Masters students
• Projects for WWU Bachelors students
• List of recent and current supervised students

Here are some projects seeking graduate students:

1. Determining the crystallization kinetics of garnet at Townshend Dam. I have a student doing an intensive project on a rock from Townshend Dam, Vermont, and I have recently (May 2009) received NSF funding for additional work in these rocks. The project is designed to combine Sm-Nd garnet dating with microprobe analysis to provide the first-ever direct measurements of nucleation rates. However, it would be useful to also attempt to model the crystallization history of this rock as well, in order to compare model results to the data that Jen will be collecting. This project would involve CAT scanning the rock, analyzing the data, and doing kinetic modeling.
2. Low-grade metamorphism in the Crescent basalts. I've got a manuscript looking at metamorphism along a transect across the Crescent basalts, a 16 km-thick set of basalts on the Olympic Peninsula that are metamorphosed to no more than greenschist (although there's hints of incipient blueschist metamorphism). A good project would be to look around in other places on the peninsula to see if the basalts there may also be metamorphosed similarly. This project would involve fieldwork, sample collection, possibly some mapping, microprobe analysis, bulk chemical analysis, and thermodynamic modeling.
3. Looking for evidence for heat-flow-controlled metamorphism. There's some evidence to suggest that in certain situations, the supply of heat to a rock might control the rate of metamorphic reactions. We would predict from this idea that crystal sizes of garnets right at the isograd would be a bit larger than those higher up. Looking for rocks to test this prediction around a contact metamorphic aureole would be a good project. There's a likely aureole in Canada. This project would involve field work, mapping, sample collection, crystal size analysis, and kinetic modeling.
4. Adding to the dataset of baric (pressure) estimates for the Cascades Core. The baric (pressure) history of rocks in the Cascades is the key to understanding the tectonics of these rocks. A new technique based on micro-Raman spectroscopy has the potential to add dramatically to the dataset of pressure estimates. It requires only a spherical quartz inclusion in garnet in order to obtain a pressure estimate. A good project would involve using this technique on already-collected specimens to expand the pressure data set. This project would involve mostly lab work.
5. Testing the usefulness of a database of optical mineralogy properties in helping students learn petrography. The project would focus on whether Mineralogy and Petrography students can learn to identify minerals in thin section better by using a database of mineral optical properties to aid them, and would also involve helping to create the database. I plan to request NSF funding for this project in July 2009 and I'm optimistic about getting that funding (money for your research would be included in that grant). Because I'm not really a Science Education scholar myself, you would be co-advised by me and (probably) Scott Linneman. I've begun work on the database, and it should come together in large part this year and summer 2009. It would then be ready for you to use when you arrive. I've got a website for the project (I made it to get feedback on the idea from other mineralogists and petrologists). That website is here.

Note to prospective graduate students: I am planning to be on sabbatical in 2009-2010, and although I will be in town for most of my sabbatical leave, you will likely not get the close supervision you would get were I to be in the Department every day.

Here are some projects seeking undergraduate students:

1. Analyze Cascades migmatization. In his thesis, Rob Isaacson described some interesting migmatites. An analysis of how these migmatites formed would be a great undergraduate project. There are a number of types of migmatites and careful chemical analysis could reveal how these rocks formed. This could include fieldwork, but doesn't have to.
2. Analyze porphyroblastic rocks for disequilibrium. In some very cool recent work, Dave Pattison and his students have documented disequilibrium as revealed by pseudosection analysis. The question of how widespread disequilibrium is in metamorphic rocks is an important one. A careful analysis of a patchy porphyroblastic rock might reveal some interesting results: Is it possible that most reactions do not go to completion? The patchiness of many porphyroblastic rocks suggests that may be the case in those specimens. I wonder what you would find if you calculated a "local" bulk composition in (a) the garnet-bearing regions of a rock, and (b) the garnet-absent regions of the same rock. Would the pseudosections for these compositions predict the observed garnet modes (>0 in a, 0 in b)? Or is (a) closer to equilibrium than (b)?

Recent and Current Supervised Students:

Related Links:

DMH Programming

DMH Dissertation