Panel discussion on women in science - ideas?

I've got a great new dean who's an active supporter of women in science (and a woman scientist, as well). When the call went out for ideas for Women's History Month, she suggested that the scientists do something. So... we're bringing in Dr. Marjorie Chan of the University of Utah, who has a women-in-geology talk she's given as an Association for Women Geoscientists lecturer, and besides her talk, we're going to do a panel discussion on issues facing women scientists. I'm organizing it, and I think I may be moderating it.

I've never organized any sort of panel discussion before, and I've never been in the audience for anything like this. So I'm looking for ideas.

We're a small public liberal arts college, so the audience will be a mixture of faculty members and undergraduates - no grad students, no post-docs. The panel members so far include Margie and the senior woman in the biology department - we're working on finding someone else. The other someones won't be from physics/engineering or chemistry - each department has one woman professor, but they're both assistant profs, and we don't want to put them on the spot.

So what should we talk about?

Margie knows the current statistics for women in the geosciences, and the biologist knows the history of her department, so at the very least, we can talk about the history in those two fields. Some of my other ideas are:

- Debunking persistent myths about women's abilities as scientists. (Maybe more important for students in intro classes, though.)

- Discussing Virginia Valian's ideas about the ways that tiny differences in perception can lead to big differences in women's success.

- Discussing the problem of balance.

- Doing some kind of exercise like Sciencewoman recently did, thinking about our strengths and how to promote them.

- Discussing the success of our biology program in hiring and educating women.

- Brainstorming things that we can do to help women in science (both students and faculty).

Anyone led a panel like this, or been in the audience for one? Any advice for what works and what doesn't?

What makes a great paper?

'Tis the season for nominating papers for awards (at least if you're a member of the GSA Structure/Tectonics Division, like I am). The division's rules are that the nominees must still be alive, but there isn't any restriction on the publication year. (In fact, last year's award was given to a paper published in 1977.)

Two summers ago, when I was preparing to teach my first ever upper-level structural geology seminar, I looked through some of these papers to try to find something to discuss. And... I chose other papers instead. I got a copy of one (Treagus and Lisle, 1997) that seemed to ask fundamental questions about the discipline, but I didn't end up using it, because it seemed too theoretical for the interests of my students. I haven't even read most of them. I've got the three books on my shelf (Pollard & Fletcher, 2006; Passchier & Trouw, 1996, and Ramsay & Huber, 1983), and have meant to read them, but in the end, I've only read sections as I needed information. (I've been meaning to read Pollard & Fletcher and blog my way through it, because I found myself needing to stop and think about the material frequently. But that's pretty far down on my to-do list right now.) And I've only read three of the papers (all while I was an undergrad). (I also recognize five more as papers that I really should have read, and that I've seen cited and listed as great papers for class discussions, and yes, I do feel guilty about not having read all of them.)

So my experience with the Best Papers is pretty limited. But at least for those three, I agree with the choices:

Davis, Suppe, & Dahlen (1983) The mechanics of fold-and-thrust belts and accretionary wedges.
I think about this paper every time I shovel my driveway. It's an important paper because it solves a big problem (how do thrust faults manage to move stuff so far?), it's led to a fruitful model for understanding mountain belts all over the world, and it's got practical use (because thrust belts are so important for oil exploration). It transformed the way that we think about one major type of structure. I don't make students read it, in part because there's a lot of math (and although it's explained very clearly, a lot of my students are math-phobic, and I want them to understand the concepts even if they get lost in algebraic manipulations). But it's also a weird paper for structural geology - so much of structural geology involves using evidence from a particular place, either field evidence or GPS or modeling. Davis et al. derived a new way of thinking of a major type of structure from first principles. Very cool, and very powerful. But as a model for "this is the way a geologic paper is written," it's an anomaly, because it's making a different kind of argument from the ones we usually make.

Platt (1986) Dynamics of orogenic wedges and the uplift of high-pressure metamorphic rocks.
I read this paper repeatedly during grad school, because it essentially inspired my dissertation. Here's the gist, for people who haven't been obsessed by (and then disillusioned with) high-pressure metamorphic rocks: blueschists are way cool, because they form at unusually low temperatures for their high pressures. The only place where they form is in subduction zones, where cold rocks are shoved into the mantle at faster speeds than heat flows - they get buried too fast to heat up. They're only found in a few places around the world, in places that used to be subduction zones (or still are, in some cases). Blueschists were yet another puzzle that was solved by plate tectonics, but in this case, the solution created another problem. If blueschists form in subduction zones, where rock is sliding down into the mantle, how do they get back to the surface? To make matters worse, the mineral assemblages that record the metamorphism can be transformed if they get heated up (which is probably the reason why there aren't many good blueschists in Vermont, or in Precambrian rocks, or in my %$&@@! dissertation field area).

John Platt proposed a solution to the problem that used Davis et al.'s wedge idea: blueschists could be exhumed during subduction (which would keep them cold) if the wedge dynamics worked out correctly. The wedge needs to keep a constant shape (according to Davis et al.'s analysis), so if you add material to the bottom of it, you can force the wedge to spread horizontally, which would move rocks toward the surface. Presto! Exhumation!

In retrospect, this paper doesn't seem as powerful as it did when I first read it. For one thing, I wonder if Davis et al.'s model works for metamorphic rocks. (The derivation is based on the behavior of brittle rocks. If the rocks are ductile - whatever combination of plastic and viscous behavior you need to explain the various deformation mechanisms - does the wedge theory actually work?) For another, the only talks I've seen that have applied the model successfully in the field have been by John Platt or his students. (Of course, I may just be cranky because there weren't any well-preserved blueschists in my dissertation area, so I couldn't test the model myself.)

The third one of the papers that I've read is Paul Hoffman (1988)'s paper on the Precambrian assembly of North America. It's an interesting example, because it's an Annual Review, not a new research paper. It's the kind of thing that I'm more likely to assign in a class, however, because it pulls together ideas from a lot of different research and summarizes it in a way that's easy to digest. I haven't used it in class, because there's been enough new research on the Precambrian geology of North America that the paper is now somewhat dated.

***

What about the rest of you? Have you read any papers on the list below? Are there any that I really should read? And what do you think a Best Paper should do - should it change the way we think? Should it inspire new research? Should it summarize the state of research in an accessible and elegant way? Should it be a nice example of how research should be done (which was how a couple of the papers awarded in this decade have been described)?

And are there any papers that really should be on this list? (How about Tanya Atwater's original paper on the San Andreas Fault - the paper that brought plate tectonics onto land? Or for metamorphic people, Phil England & Alan Thompson's paper on metamorphic pressure-temperature-time paths? Or anything about metamorphic core complexes?) Would it be better to have recent papers, to show that the field is still dynamic (no, really, it is!), or should we recognize the classic papers that have shaped the field?

For reference, here's the list of all the papers ever given the Best Paper Award, stolen from the Structure/Tectonics Division web page:

2008: Thomas, W. (1977) Evolution of Appalachian-Ouachita salients and recesses from reentrants and promontories in the continental margin. American Journal of Science 277, 1233-1278.

2007: Pollard, D.D. & Fletcher, R.C (2006) Fundamentals of Structural Geology. New York, Cambridge University Press. 512 p.

2006: Dixon, T.H, Miller, M., Farina, F., Wang, H. & Johnson, D. (2000) Present-day motion of the Sierra Nevada block and some tectonic implications for the Basin and Range province, North America Cordillera. Tectonics 19, 1-24.

2005 (2 awards): Beaumont, C., Jamieson, R.A., Nguyen, M.H. & Lee, B. (2001) Himalayan tectonics explained by extrusion of a low-viscosity crustal channel coupled to focused surface denudation. Nature 414, 738-742.

Hodges, K.V., Hurtado J.M. & Whipple, K.X. (2001) Southward extrusion of Tibetan crust and its effect on Himalayan tectonics. Tectonics 20, 799-809.

2004: Atwater, T. & Stock, J. (1998) Pacific-North America plate tectonics of the Neogene southwestern United States - An update. International Geology Review 40, 375-402.

2003: Lavé, J. & Avouac, J.P. (2000) Active folding of fluvial terraces across the Siwaliks Hills, Himalayas of central Nepal. Journal of Geophysical Research 105(B3), 5735-5770.

2002: Catuneanu, O., Beaumont, C. & Waschbusch, P.J. (1997) Interplay of static loads and subduction dynamics in foreland basins: reciprocal stratigraphies and the "missing" peripheral bulge. Geology 25(12), 1087-1090.

2001: Dunlap, W.J., Hirth, G. & Teyssier, C. (1997) Thermomechanical evolution of a ductile duplex. Tectonics 16(6), 983-1000.

2000: Passchier, C.W. & Trouw, R.A.J. (1996) Microtectonics. 289 p. Springer.

1999: Treagus, S. & Lisle, R. (1997) Do principal surfaces of stress and strain always exist. Journal of Structural Geology 19, 997-1010.

1998: Muehlberger, W. (compiler) (1992 & 1996) Tectonic Map of North America. American Association of Petroleum Geologists (two sheets).

1997: Molnar, P., England, P. & Martinod, J. (1993) Mantle dynamics, uplift of the Tibetan Plateau, and the Indian monsoon. Reviews of Geophysics 31, 357-396.

1996: Suppe, J., Chou, G.T. & Hook. S.C. (1992) Rates of folding and faulting determined from growth strata. In: Thrust Tectonics (edited by K. McClay). Chapman & Hall. London, 105-121.(Click here for citation and response)

1995: Wojtal, S. (1989) Measuring displacement gradients and strain in faulted rock. Journal of Structural Geology 11, 669-678.[awarded in 1996]

1994: Armijo, R., Tapponnier, P. & Han, T. (1989) Late Cenozoic right-lateral strike-slip faulting in southern Tibet. Journal of Geophysical Research 94, 2787-2838.

1993: Worrall, D. & Snelson, S. (1989) Evolution of the northern Gulf of Mexico, with emphasis on Cenozoic growth faulting and the role of salt. In: The geology of North America - an overview (edited by Balley, A.W. & Palmer, P.). Geological Society of America Decade of North American Geology A, 91-138.

1992: Hoffman, P. (1988) United plates of America, the birth of a craton: early Proterozoic assembly and growth of Laurentia. Annual Reviews of Earth & Planetary Sciences 16, 543-604.

1991: Pavlis, T. (1986) The role of strain heating in the evolution of megathrusts. Journal of Geophysical Research 91, 6522-6534.

1990: Engebretson, D., Cox, A. & Gordon, R. (1985) Relative motion between oceanic and continental plates in the Pacific basin: Geological Society of America Special Paper 206.

1989: Platt, J.P. (1986) Dynamics of orogenic wedges and the uplift of high-pressure metamorphic rocks. Geological Society of America Bulletin 97, 1037-1053.

1988: Simpson, C. & Schmid, S. (1983) An evaluation of the criteria to deduce the sense of movement in sheared rocks. Geological Society of America Bulletin 94, 1281-1288.

1987: Boyer, S.E. & Elliott, D. (1982) Thrust systems. Bulletin of the American Association of Petroleum Geologists 66, 1196-1230

1986: Davis, D. Suppe, J. & Dahlen, F.A. (1983) The mechanics of fold-and-thrust belts and accretionary wedges. Journal of Geophysical Research 88, 10087-10101.

1985: Ramsay, J.G. & Huber, M. (1983) The techniques of modern structural geology: Volume 1: Strain analysis. 307 p. Academic Press.

1984: Coney, P.J., Jones, D.L. & Monger, J.W.H. (1980) Cordilleran suspect terranes. Nature 288, 329-333.

Citing references outside academia/government?

Here's another question on writing done by geoscientists outside academia. How do you give credit for work done by others?

In academia (and anywhere else where research is done, including government and industry), citing references is necessary both to put work in context and for ethical reasons. And in classes, it's a huge deal. But the typical citation styles used by geoscientists (whether the USGS style, AGU, or other journal styles) can be pretty distracting - you're reading a perfectly clear sentence, and then it's broken by an entire line of parenthetical references:

(Hatch, 1987; Hatch, 1988; Moench et al., 1995; Rankin, 1996)

My students frequently complain about this reference style - the names don't mean anything to them. So I wonder about other audiences, especially in industries where your audience wants to get to the point, as quickly and clearly as possible.

There are plenty of cases beyond academia (and government or industry research) in which a geologist is likely to rely on work done by someone else. New field work is expensive (and drilling holes even more so); if you can use existing maps, published geochemistry or structure or stratigraphy, I imagine that a good mining or petroleum geologist could identify likely targets. There might be useful information in USGS maps, state survey data, dissertations... all sorts of places besides proprietary data. And if demand for a commodity makes new types of plays profitable (such as is going on now with shale gas or coal-bed methane), then I imagine that all sorts of old studies could become valuable (such as dissertations on joints in the Marcellus Shale, or old proprietary data about areas that weren't economic a couple decades ago). So, if you're working in exploration, and you're writing an internal report about an area that deserves further exploration, how do you cite the old studies? (Do you write an executive summary that management can skim, and give references in documents aimed at other geologists?)

(If you haven't guessed, I'm still thinking about justifying the academic writing my class is doing. I've become more and more aware that I'm not training academics, for the most part, and my own experience just isn't adequate.)

Want to share proposals with my students?

In the comments on my post yesterday asking about non-academic proposals, Suvrat asked if I was going to show my students examples of successful proposals. The answer is yes... and I'm looking for help in showing students a wider variety of proposals, both from academics and non-academics.

I've written proposals and gotten them funded, from NSF, from internal pots of money, and from local foundations. But I'm just one person, writing proposals for my pet projects, and I know from reviewing for NSF and from serving on a foundation's grant-awarding committee that there are many styles of proposals that work.* I'm planning to ask other members of my department if they would be willing to share their proposals with my students as well, but there are only six of us, and we're at a teaching-intensive institution. And my students already know a lot about what we do, because they're talking to us about possible senior thesis topics.

So I'm asking around for other examples. For academics, would any of you be willing to share a successful proposal (from any organization, large or small) with my students? I'm willing to hide any part that you don't want to share, and I promise not to steal research ideas - I don't have time to steal ideas from other people, honestly - or to tell my colleagues about work you plan to do. In return, you get to sell your research to 15 juniors who may want to do graduate work someday. (And I've found that students can really be influenced by examples of research that they see. That's another reason to avoid focusing on my work - I don't want my students to feel pushed to become my clone.)

For non-academics... well, I imagine that it's trickier to share proposals or bids for contracts, especially for people doing exploration work. So don't offer anything that would be against the policies of your employer. But if anyone has examples, or ideas for how to create my own, or would be willing to replace identifying information with imaginary places, I would love to show students something non-academic and realistic.

For everyone: here's how I'm thinking of using examples. I want students to think about what proposals have in common, and what's different depending on the type of work and the audience. So I'm thinking of assigning pairs of students to look at different proposals, and asking them to figure out who is the audience, what's the proposed work, how the work is justified (or what kind of details are offered as supporting evidence), and what things are left out. (Any ideas about what else the students should look for?) Then I'm planning to spend one class discussing the similarities and differences between proposals.

The students will have the opportunity to write their own proposals to different audiences in any case - they need to get their advisor's approval for their thesis proposal, and they get a grade from me, and if they need money to complete their project, they have to write proposals for funding, as well. (The college has some money for undergraduate research, but it's awarded competitively, and the committee that reads the applications includes people from all over the college. The differences between successful departmental research proposals and successful funding proposals can be an educational experience. Also frustrating, as learning experiences frequently are.)

Thanks to anyone who is willing to help. If you want to share materials privately, my e-mail address is shearsensibility AT gmail DOT com. (Replace AT with @, DOT with . , and take out all the spaces.) Or alternatively, you can find my work e-mail by googling my real name.

*There are also many that don't work. I've learned a lot from my own rejections (and from reviewing).

Proposals (etc) outside academia?

If you're working as a geoscientist outside academia - in oil & gas, in mining, as an environmental consultant, for a government agency, for a non-profit organization, or in some other career - do you write proposals? Not NSF grant proposals, like your professors constantly did, but some kind of writing to get permission or funding to start a project?

I'm asking because I'm about to start teaching my department's writing class again, and the class is designed to develop writing skills while writing a proposal for a senior thesis. When I arrived here and took over the class, it was a general education requirement (writing within a discipline). That's changed recently, but after I tried to make it more relevant by using it to prepare students for their research, the department decided that the class was too important to drop from the major. So I'm still teaching it, but I want to make it as valuable as possible to all my students - not just those who plan to go on to graduate school.

Thus my question. I tell students that writing is a skill that they will be able to use regardless of what they do. (My usual line is "If you can write, do math, and think critically, you should be able to do a lot of different jobs, not just the ones you think you're training for.") Part of my argument is that people have to write in all sorts of different careers. Geologists have to write reports discussing what they've found - even recent grads have told me that they spend a lot of their time writing reports. But I also tell students that writing proposals (or maybe bids, in the case of consultants) might also be part of their work. But I don't have direct experience with them, so I don't know much about the details.

So, for those of you who work outside academia: do you write proposals? At what level - are proposals written by people at a certain level of the organization, but not by the underlings? For those of you who have written your own proposals (which would probably include anyone who has been to graduate school), have you been able to translate your experience to the professional world? What kind of advice would you give to undergraduates who are learning this kind of writing for the first time?

Experience with non-PV solar technology?

Does anyone out there have experience working with non-photovoltaic solar technology? Anything from the theoretical to building your own solar hot-water heater? I've got a writer friend who is working on an article on solar thermal technology. She's especially interested in talking to people who have experience with small-scale projects (like a water system for a home), but she's interested to talking to anyone who can help her understand the background, too.

I vaguely remember talking about semi-off-the-grid ideas when I was in high school. (A friend had an indoor swimming pool that may have been partly solar, but I think it was also heated by a wood stove. That was Maine, and the sun doesn't shine as much there as it does in Colorado.) But although I know people from grad school who rebuilt diesel engines to run on used cooking oil, it's been a long time since I've talked to anyone who does their own passive solar. (Beyond south-facing windows, that is.)

If you've got experience or know people who do, could you e-mail me (shearsensibility AT gmail DOT com), so I can pass contact information along to my friend?

How important are GRE scores for geoscience grad school?

I took the GREs twenty years ago this month. Twenty years! I spent an entire day of my Christmas break in a big lecture hall at the University of Maine, filling in bubbles with my #2 pencil.

The world has changed in the past twenty years. GREs are taken on computers these days, and the bizarre but fascinating logic problems are gone. ("Jenny likes cabbage, but Fred is allergic to horseradish. Who is seated beside Louise?") There's a new writing section, along with the verbal and math sections. And there's no longer a geology subject test. So I've become less and less capable of giving any kind of reasonable advice to students about how to prepare for it. And because I don't read grad student applications, I don't have any idea how grad schools look at the current version of the test.

When I started grad school, I got the impression that the GREs weren't particularly important for anything except competing for NSF graduate fellowships. Research is not a multiple choice exam, and the ability to fill in little bubbles (or whatever mouse-click has replaced it) is no substitute for creativity, perserverence, and the ability to take a lot of criticism. I've gotten the impression that the things that matter for a graduate application are 1) a coherent statement of purpose that fits with the research interests of a faculty member; 2) good grades in relevant coursework (maybe geo, maybe math or chemistry or physics); 3) strong letters of recommendation; and 4) maybe research experience, although it's become common enough at the undergraduate level that it might not mean as much these days unless it's incorporated into the statement of purpose. The GREs - well, the general test is taken by everyone, from physicists to literary scholars, and it would be hard to come up with a test that could identify people who would be skilled at both subjects. I remember the verbal section as being essentially the SATs with longer words (but not geology jargon), and the math section as being algebra. I took it, I sent off the scores, and I never thought about the test again*. Until students came to me worrying about it.

So here's my question to the rest of the world. Based on your experience, do GRE scores matter? Do some schools put more weight on them than others? Is there a minimum cutoff score for some schools, or are they used as a tie-breaker between otherwise similar applications? Or are they a form of practice at jumping through hoops, preparation for things like dissertation formatting instructions?

*Well, other than to score geek points against my soon-to-be-ex college boyfriend. But once I got to grad school, I didn't think about the scores.

Got a new science building? Want to tell me about it?

The science departments here are in a building phase. Chemistry got a new building a few years ago, biology is getting a new building right now... and just this morning, we learned that physics, engineering, and the geosciences have the go-ahead to start really planning a new building ourselves.

So now we want to know what cool things other institutions have done recently. If you know of a new science building (and especially a new geology, physics, and/or engineering building) from the past ten years, especially one that uses green building standards, make innovative pedagogy possible, or facilitates undergraduate research*, we'd like to talk to you (and maybe visit your building). (Has anyone taught with a Geowall, or learned with a Geowall? How about the new microscopy labs with digital cameras and computers, which make collaborative learning possible in optical mineralogy and petrology? Those are a few things that I know about, but I would like to know about what things are so new that I haven't heard about them, as well.)

You can contact me at my work e-mail (just google me - you'll find it) or at shearsensibility AT gmail DOT com.

*The president is interested in knowing what research universities do as well as knowing what undergrad institutions do. He wants to make sure we're thinking for the future, which is a good thing, since that's what planning's supposed to involve.

Open question for readers: surviving calculus

I just got this question in a comment to another post, and I thought I would throw it out there for readers to help with:

Anyone out there have to take a year of calculus even though it wasn't their strongest subject? How did you survive?

I would love to know answers to this question as well. Not because I'm struggling through calculus myself, but because many of my students are, and I'd like a larger toolkit of suggestions for them. At the end of this summer, I went to a discussion with the math department about ways to help students succeed in the precalculus-calculus sequence, and if anyone has great ideas, our math department has a big education grant and might be able to implement some.

(In the meantime, lacking any better ways to help my students succeed in calculus, I let my structure lab go early - during the stereonet lab, no less - because half the class had a group calculus exam scheduled to start right when the lab was supposed to end, and I didn't want them to go into their exam feeling overwhelmed and confused by stereonet rotations. Oh, and to former students, I was planning to give them a short lab next week anyway, so I'm just going to do rotations and drill-hole problems then.)

My approach has been to point out the connection to calculus concepts whenever I see them. (Strain rate? Derivative! Oh, and how is a graph of stress vs strain rate related to a graph of stress vs strain?) That, and to make the students use algebra as much as possible in a geology context, because it seems like succeeding in precalculus and calculus is often a matter of doing algebra well. It would be nice to have more suggestions beyond the math cheerleading, though.

Advice wanted: rugged digital cameras

I went on a lovely hike above 11,000 feet today, checking out the access for a structure field trip in a few weeks. There was a dusting of snow on the north side of some peaks, remnants of a storm a few days ago, and I took a picture of a great angular unconformity (Precambrian gneisses beneath young volcanics).

And I can't show you any pictures, because I dropped my digital camera on the ground and broke it.

(Actually, the story is more complicated, and involves a five-year-old taking photos of an artistic arrangement of hand-held radios on the tailgate of the truck, and a mother with clumsy hands reaching for the camera at the same time as he reached for it. But it doesn't matter. The camera has a dent, and the lenses won't retract.)

So I'm in the market for a new camera. And I'm curious what features the rest of you have found useful. I know I want something with macro capabilities, and with decent resolution. The old camera was very lightweight, but I would be willing to carry something heavier if it were a bit more rugged. I would also like to find something with batteries that I could replace in the field - if I'm backpacking, I can't use my charger.

I am not a great photographer, and even in the days of my entirely mechanical 35 mm, I never got really good at adjusting f-stops and shutter speeds until I got the best image. (I never got the hang of the manual settings on my broken camera, either. I don't know if that means they were poorly designed, or whether I just didn't have the patience to play with them enough.)

Any suggestions for things I should be looking for, this time around?

(And any suggestions for an inexpensive but rugged digital camera that a five-year-old can experiment with? I want to let him explore his interest in still-life images of outdoor gear, but, ummm, not with my camera.)

What kind of compass do you prefer?

I see that eight nine people have already voted in the poll I put up yesterday, even though I haven't found time to blog about it until tonight.

I'm putting together my classes for this semester. (I don't start until Sept. 1, so I've got a few more days.) One of the classes I'm teaching is our sophomore-level field methods course. The title might be misleading - the course is an introduction to geologic mapping, and leaves out many other things that geoscientists do in the field. (In fact, my intro class will be doing some of them in their stream lab.) On the other hand, geology isn't just a set of technical skills that one is trained to do - a geologist should be able to imagine what's hidden underground*, as well, and the skills in this class are designed as one step towards developing the ability to think spatially.

Geologic maps show what rocks are found near (or at) the surface, but they also provide the information needed to make a good guess at what might be hidden underground. That information comes from the orientations of layers of rock, and of fractures and cleavages and faults. And to find that information, we still use big, clunky, old-school geologic compasses. (GPS is great for figuring out where you are, and we use those, too. But the compass is still a basic piece of equipment.)

When I was young (*shakes cane*), I learned to measure bearings by measuring angles from north or south:



If that arrow in the middle of the circle was... oh, let's say it's the direction a current used to flow. I would have measured the direction of the arrow as being 45 degrees east of south (or in my field notes, S 45 E).

But that's not the only way to measure angles. A circle can be divided into 360 degrees, and compasses can measure bearings around a circle, starting with north and then spinning through east (at 90 degrees), south (at 180 degrees), and west (at 270 degrees), and finally getting back to north, if they didn't get dizzy and fall down in the meantime. Those kinds of bearings are known as azimuths. They're easier to deal with mathematically, because they're one number, always measured in the same direction. They confused me when I first dealt with them, because I'm lousy at memorizing numbers. (I hate combination locks.) I've gotten used to them, though, because I've worked with people who prefer them.

I always used to think that quadrant measurements were more intuitive. I think about directions as "southwest", not as "a bearing between 180 and 270 degrees." And I carry a protractor that measures angles between 0 and 180 degrees easily, but which requires me to subtract larger numbers in my head. (And I make mistakes when I do arithmetic in my head.) I prefer to make my maps in the field - they are tools for helping me think about what's going on, and if I wait until evening (or later) to compile them, I might have to hike miles and miles back to the same spot to collect more data. And that means that my favorite compass is one that gives me numbers less than 180 degrees.

I've seen more and more students who are at least as comfortable with azimuth measurements as with quadrants, though. And at least three of my colleagues prefer them. (And I've got a sinking feeling that I'm just hideously old-fashioned for carrying a quadrant compass.)

I'm not going to trade in my compass. It was expensive, and it still works, and I'm capable of converting the different measurements. (I can almost do it in my head. If I practice enough. Grading 20 labs every week gives me lots of practice.) And I always make students convert their measurements back and forth. (I still need to do the math in my own head, though, to check them.) But I'm curious what the current trends really are. Does anyone prefer quadrant compasses, or are people switching entirely to azimuth? Are the azimuth people primarily geophysicists? (Paleomag is easier in azimuth, I believe.) Are azimuth bearings easier to handle in GIS?

And if I carry a quadrant compass, should I carry a sliderule, too?

*Yes, I realize that may be a structural geologist's bias, but you know... in grad school, I could have been a geochronologist or a metamorphic petrologist. I've become a structural geologist by necessity, because my departments needed someone to teach spatial thinking more than they needed someone to unravel the exhumation histories of metamorphic rocks.

Some of these rocks are not like the others...

I've been out scouting field trip sites for my intro class, and I want to test some observations. Non-geologists, I need your help! I've got four pictures here. The last two are of the same rock - the second is just a close-up picture taken a few inches from the first.

I'm curious what you see when you look at these pictures (aside from my office keys, which were the handiest thing available to use for scale). How are the rocks similar? How are they different? Any speculation on why they're different?

Rock #1:


Rock #2:


Rock #3:


Rock #3 up close:


(I'm asking because I'm thinking about how to get my students to look at the rocks like geologists do. My eyes have been trained to see certain differences, but I've found that my students don't see them. Maybe if I know what other people see, I'll be able to ask better questions in my lab.)

(Oh, and Mom: no, I didn't leave the keys on the outcrop. They are... ummm... oh, yeah, they're here on my desk.)

PS: I'm more interested in what you see than what you would call each rock. (The students won't have learned the terminology yet. I'm curious what they might see before they get caught up in memorizing new words.)

Geology terms overdue for retirement?

In the last couple weeks, I've heard a number of comments about geology terms that are unnecessary or outmoded. The Cordilleran tectonicists at the Las Vegas GSA meeting kept making jokes about how they weren't supposed to use "miogeocline" (which means essentially passive margin, and which replaced "miogeosyncline" after plate tectonics became accepted). "Greywacke" also seems to be on its way out. In the geoblogosphere, Olelog asks whether we need the word euxinic. And then there's this wisecrack from Ammon Shea, who is writing a book about reading the Oxford English Dictionary:

For instance trondhjemite is defined as ‘Any leucocratic tonalite, esp. one in which the plagioclase is oligoclase’. I have my doubts as to whether anyone has ever thought to themselves ‘I wonder what trondhjemite means?’ But if someone did, and went to look it up in the OED, it seems unlikely that this definition would clear things up much.

I disagree with Shea. I know what a tonalite is, and I know what oligoclase is, but I often need reminding of the precise definition of "trondhjemite." I've got even more problems remembering the definitions of other igneous rock names ("alaskite," "pantellerite," "hawaiite," "benmoreite," etc.) but that's partly because I've worked in Precambrian rocks, and lots of Precambrian geologists talk about trondhjemites. So I think the definition in the OED is useful, but I'm not so sure that the term itself ought to remain in active use. (By the way, if Shea wants a really impenetrable geologic definition, he should see the definition of cactolith.)

So I'm curious. If you could get rid of five geologic terms as unnecessary and/or outdated jargon, which ones would you choose?

Panning, panoramas, and powerpoint?

I've got a question for visualization gurus. (Or, well, anyone better at Powerpoint than I am, which is probably everyone. I still like slide projectors.)

Is there a good way to use a panorama in Powerpoint? Anything that can allow you to pan from one side of the image to another, or to zoom in to particular spots? (Ron, have you used gigapan images in Powerpoint, or do you normally open them in a separate file during class presentations?)