Understanding the Deep Earth

Online Workshop

EarthChem (www.earthchem.org) has recently added a great new Deep Lithosphere Petrological Dataset that contains major and trace element, and isotopic data for whole rocks and minerals from mantle xenoliths, with over 2000 sample datasets archived. It would be great if someone (or a small group) could put together some new problem sets that access these xenolith data--geochemical modeling, thermobarometry, etc. to add to the tutorials and activities we've already compiled at our EarthChem Geochemical Database teaching module: http://serc.carleton.edu/research_education/cyberinfrastructure/index.html

Thanks to Roberta Rudnick for contributing these great data to EarthChem!

For the Mineral Physicists out there, I could really use some good teaching materials on phase transitions--perhaps an introduction to the various types of phase transitions (displacive, reconstructive, order-disorder), some demonstrations of how they work, and a problem set or two about how an understanding of phase transitions can be applied to studies of Earth (maybe something about volume change related to phase transitions, density changes that result in seismic discontinuities, the significance of olivine-beta phase transition, perovskite, post-perovskite?). I would use this in my mineralogy class.

Does anyone out there have some really good problem sets using MELTS? It would be great to have some examples about how we can model melt behavior of various mantle reservoirs, and determine the resulting melts that can be derived (maybe also as a function of water activity, fertility of the starting composition, oxidation state, melt fraction....). These would be great additions to our tutorial on MELTS, in our Teaching Phase Equilibria module: http://serc.carleton.edu/research_education/equilibria/melts.html

This post was edited by Glenn Richard on Feb, 2010
As I mentioned in the "Introductions" thread, there is a need for educational resources that focus on:

1) the properties of materials under deep Earth pressures and temperatures;

2) the technologies, equipment, and facilities needed to study materials under deep Earth conditions; and

3) what materials properties research has revealed about deep Earth processes.

Regarding technologies, I worked with a group of students to develop an interactive applet that demonstrates Bragg's Law. See http://www.eserc.stonybrook.edu/ProjectJava/Bragg/

During this workshop, I am considering developing some educational activities that utilize this applet, but am primarily interested in helping other workshop participants with their projects.

I am happy to see that other members of the COMPRES community are enrolled in this workshop. Perhaps some of them can help stimulate ideas for additional educational resources by posting their thoughts to this thread prior to the start of the workshop.

This post was edited by Caroline Kralovec-Kirchherr on Mar, 2018
I think there is a need for better exercises that demonstrate how seismic waves are used to image the deep earth. We have an exercise written for 9th graders that leads students to use seismic data to discover the outer core (www.iris.edu/hq/resource/determining_internal_structure) and i'd like to know if anyone has anything similar written at the college level.

I'm also looking for activities which help explain the process of seismic tomography.

IRIS has a large online archive of seismic data, along with several access tools and we are interested in working with anyone who wants to help develop activities using that data, as we would like to expand our resources for the college audience.

In the Introductions thread, Pam Burnley wrote:

"In geophysics I used to have my students figure out what the earth would need to be composed of if it were hollow (using a shell thickness suggested by hollow earthers) given the radius determined by Eratosthenes and mass determined by Maskelyne. I always found that amusing but my students tended to founder on the math."

Pam, are you aware of any existing online resources that could be effective for helping students understand the math? If not, can you think any new resource that could be developed to facilitate this understanding?

In the Introductions thread, Kanani Lee wrote:

"In terms of teaching, I am looking for more hands-on activities for my students, perhaps even some that takes them out into the field. My "field" is the laboratory which can come across less-exciting, especially for someone taking a geology course. Currently I do a corn syrup demo and try to measure gravity changes with a gravimeter. We've also set up some geophones and hammered away to show some reflection seismology. I could use more ideas."

Kanani, do you have any support materials for your lab tours, or descriptions of the corn syrup or geophone activities that you would like to share with us?

When I was at U Wyoming someone (I think Jim McClurg and Ritchie ??) had developed a mac-based program that let students play with thicknesses of layers inside the earth and densities for the layers. The goal for the students to was develop a model for a layered earth that matched the observed bulk density. Not sure how hard it would be to reproduce something like this as a web-based activity (maybe including something about other bulk properties to help students get to a better fit??)...

I also wonder about trying to get Wards or some other vendor to put together education teaching suites that might include a small polished bit of Fe meteorite, a sample of perovskite (not sure how easy this is to obtain), garnet peridotite and spl peridotite for a reasonable price [Dave I know some suites were developed and sent out for Teaching Petrology - don't know if there would be a way to do this for lesser cost through SERC???]

Ben--one of my long term goals for Teaching Petrology has been to put together suites of rock samples including hand samples, thin sections, links to geochemical datasets for these rocks (whole rock, trace element, isotopic...) so that we could do integrated mineralogical, petrological and geochemical problem sets. Mike Perfit at U Florida did a nice job putting together suites of MORBs as a follow up to Teaching Petrology, and some of this information is available online, and he also has a set of rock samples and thin sections that can be requested on a rotating basis. I haven't quite figured out the best model for delivery: a rock e-bay in which you could purchase suites? A swap-meet such that every campus could swap their best samples for sets of samples from other locales (e.g. I could really use some blueschists and eclogites here in MT, but can offer Archean basement, Stillwater, etc.)...

It might be interesting for someone to put together a collection of Deep Earth samples: lower crust and mantle xenoliths, as Ben suggests some analogues for even deeper earth (perovskite, Fe-meteorite) etc. We could at least help post this info as a virtual collection--post photos of rocks, photomicrographs, geochemical data sets, physical property data....Not quite sure how to distribute real samples but I'm open to suggestions.

BTW, folks might be interested in looking at Barb Dutrow's article in Journal of Geoscience Education, Teaching mineralogy from the core to the crust v.52 p. 81-86

Dave--

1. Phase transitions: At the CIDER workshop this coming summer in Santa Barbara (http://www.deep-earth.org/) one of the mineral physics lecturers is planning an interactive tutorial activity on phase transitions in the deep Earth. Not sure yet what this will look like but I will keep my eyes open.

2. Deep Earth samples: I have a collection of hand samples I use for showing deep Earth materials: a chondrite meteorite, and iron meteorite, mantle peridotite (San Carlos), ocean basalt, and a nice granite. I use them for show and tell, and to demonstrate density.

Abby, re: Deep Earth samples... I like that you go all the way from core to crust in one series. A colleague brought meteorites into Petrology this year to talk about the core and bulk Earth, etc, but she also had thin sections for the samples, which I thought was a neat perspective.

I'm lucky in that the Smithsonian is only 2 hour drive from Dickinson, so I've started taking my Min/Pet class there for a 'behind-the-scenes' tour of the rock and mineral collection, plus some of the experimental/analytical facilities. For people further away I know it's not really within reality to take a class trip there, but what they have is obviously spectacular for people who can make the trip.

Part of the reason for mentioning this is that we always get a tour of the meteorite collection (the students got to hold a likely piece of Mars last fall), and I know that they have thousands of samples, many of which are available for research 'loans'. I wonder if they might be open to making long-term 'loans' of small pieces of meteorites for teaching?? Having a polished piece of iron meteorite showing W-S textures is very nice for visualizing the inner core, and a piece of pallasite gives an approximate idea of what D'' might be like. I know their collection is mainly for research, but they have so many samples it would seem reasonable to get some long term loans.

Two other possibilities to facilitate this might be to try and form regional groups, which might be able to coordinate and share a Smithsonian 'loan' collection, or trying to see if NSF/SI would be willing to fund some annual 'rock tours' for SI petrologists/mineralogists to bring to the Smithsonian samples to groups of students, coordinated with classes. This would be maybe more attractive if local college/uni hosts could organize visits to local K-12 schools as well...so the SI would get a big return for the travel investment.

I know some places in BC where I could easily collect hundreds of spl peridotite xenoliths, and have seen some retrograde ecologites in North Carolina. The 'best' eclogites I've seen are of course from Norway, but most of the garnet peridotites I've ever seen are from kimberlites, and it's not very easy to get samples...not sure I know any Norwegian petrologists that could coordinate a large-scale rock swap...do any of you??

PS - I've had an undergrad work on mylonitic spl peridotite xenos from some of the volcanic cones in Baja California, which could make a gneiss addition to a deep earth sample suite in that they show the solid state deformation that must be(?) a big part of mantle convection cells...