All of My Faults Are Stress Related

Callan Bentley has declared a meme:

What are ten things that every geology major ought to know about? The only restriction is you’re not allowed to list anything that has already been listed by a previous geoblogger. You don’t have to list everything, just ten important things.

Before I add to the list (which has already gotten quite long): Callan, I hope you’re not planning to bring back the geology subject GREs or something. I took them. I swear I got maybe half of the questions right, and still ended up with a score in the 90-somethingth percentile. I’m glad they’re gone. (And if we did this exercise in my department, in order to develop some kind of assessment tool, I would suggest another step: to go through all the other lists and cross off things that you don’t think are important for every undergraduate geology major to know.)

With that said, the list is still missing a lot of structural geology. I’m going to start with things that I want students to get out of my classes, and then I’ll cheat and add things from a class that I don’t teach any more.

My list:

  1. How to interpret the geologic history of a place (sedimentation, deformation, igneous activity, erosion) from a geologic map on a topographic base.
  2. How to draw a viable geologic cross-section, given a geologic map that shows topography and orientation of rock units.
  3. How to guess the approximate orientation of layered rocks from their map pattern, given topography.
  4. How to predict what orientations of fractures should form under various stress conditions.
  5. How to determine possible senses of offset on a fault – and that you can’t tell total offset from the offset of a layer.
  6. The difference between stress and strain, and what you can determine from different rocks.
  7. How to read a stereonet plot.
  8. How to identify at least ten different minerals using a polarizing microscope.
  9. How to figure out the identity of an unknown mineral, given enough tools (down to x-ray diffractometer or SEM).
  10. How to describe their observations and interpretations clearly and concisely, using both words and pictures.

The previous lists:

Callan at NOVA Geoblog:

  1. The relationship between cooling rate and crystal size in igneous rocks.
  2. The fact that rocks can flow, given sufficient temperature and pressure [and low strain rate, for the purists out there].
  3. The idea that sedimentary rocks reflect specific depositional settings. By studying modern depositional settings and the sediments they contain, we can interpret ancient sedimentary rocks in light of the conditions under which they accumulated.
  4. The fact that the chemical stability of molecular configurations (minerals) changes with different temperatures and pressures (metamorphism).
  5. Large Igneous Provinces, and their potential role in tectonics and expressing mantle plumes.
  6. Elastic rebound theory for the origin of earthquakes.
  7. The notion of partial melting, and its relationship to Bowen’s Reaction Series.
  8. An understanding of the carbon cycle, and an understanding of the atmospheric physics that facilitate global warming.
  9. The role that rivers play in shaping the landscape: nickpoints, terraces, quarrying, abrasion, drilling of potholes, etc.
  10. The Earth is 4.6 billion years old, which is extremely old in comparison to human life — and the reasons we think it’s so old [Pb isotopes, etc.].

Mel at Ripples in Sand:

  1. Evolution.
  2. Evidence for plate tectonics.
  3. That fossils (and trace fossils) can provide more information about the rocks they reside in – depositional environment, chronology and correlation, water temperature, stratigraphic up, relative rate of deposition, water depth, etc.
  4. And vice versa, the rocks can tell you a lot about the fossils that are contained within them – geography, taphonomy, chronology and correlation, etc.
  5. The relationship between sediment production –> sediment transport –> sediment deposition.
  6. How to identify minerals.
  7. Differentiation and fractionation and how they apply to the planet, the solar system, and isotopes.
  8. How aquifers work (or don’t work if we drain them too quickly).
  9. Where our energy supply comes from. All facets from petroleum products, to solar radiation, to conductive metals extraction, etc. (These are also useful for seeking gainful employment as a geologist.)
  10. Pedogenesis. How it takes thousands of years of chemical reactions and transport to generate the soils we use for agriculture. (And how we should be taking better care of them.)

Chris at GoodSchist:

  1. The difference between absolute and relative radiometric dating.
  2. Uranium-lead dating and how each element on the uranium 238 decay chain interacts differently with the environment.
  3. The difference between a continent and a tectonic plate.
  4. The properties of felsic, intermediate and mafic lava types.
  5. How and why the melting temperature of a rock changes depending on the the concentration of volatiles therein.
  6. What an ophiolite is and the significance of very old ophiolites.
  7. The structure of the deep Earth (the upper and lower mantle including the MoHo and other zones)
  8. The biological explanation for the formation of banded iron formations.
  9. The insignificant difference between a volcanic sill and a volcanic dike.
  10. How to spot changing environments in a stratigraphic column.

Eric at Dynamic Earth:

  1. Hydraulic Geometry: this concept relates fluvial discharge to slope, channel width, channel depth, and velocity, and explicitly shows how delicate adjustments in one can result in changes in the others.
  2. Paleocurrent indicators, and how to describe, interpret, and measure them (especially from trough axes)!
  3. What are Froude and Reynold’s Numbers, and what do they mean!?!
  4. That a lithofacies is the sum of all textural, sedimentary structural, and lithological attributes that uniquely defines a given lithosome, and how THIS DIFFERS from a depositional environment model.
  5. The basic sedimentary basin types (i.e., retroarc forelands, forearc, etc), and what subsidence patterns generally define them.
  6. Why there are locks on the Panama Canal (the Geoid!)
  7. The difference between lithostratigraphy and chronostratigraphy
  8. How to draw a Wheeler Diagram
  9. The timing and location of the major orogenies
  10. Walther’s Law

Lockwood at Outside the Interzone:

  1. Should be confident that he/she could point out evidence of change anywhere on the Earth’s surface.
  2. Should know how to (and preferably, be eager to) talk to non-scientists about their subject.
  3. Know how to use ternary diagrams.
  4. Know basic mapping skills; with a Brunton compass and a topo map, take appropriate
  5. measurements both for recording data and navigation.
  6. Given an outcrop, tell a story about how it came to be. This does not mean “get every detail right,” but at the core of our discipline is a love of stories and change over time. Bachelors degree holders should have developed some skill with this.
  7. Be able to generate alternative hypotheses (no one-handed geologists!) and recognize ways to look for evidence supporting and refuting one or others.
  8. Be able to (in broad strokes) sketch out the history of the earth in an astronomical context, and compare and contrast the earth to the other terrestrial planets.
  9. Discuss in some detail modern civilization’s utter dependence on geologic resources, including (but not limited to) water, energy, metals, building materials and nutritional materials (particularly with respect to fertilizers).
  10. Describe how geology is intertwined with other sciences (biology, chemistry, physics, meteorology, oceanography, astronomy) and with mathematics (it’s no accident that a major branch of mathematics is called GEOmetry).
  11. Be able to honestly say “I think rocks are really cool…” or some variation thereof.

Bryan at In Terra Veritas:

  1. Gravity happens
  2. The Earth is a Dynamic Entity
  3. Uniformitarianism
  4. The Earth is not a closed system
  5. Radiometric dating is not synonymous with C14 dating. While we are at it, let’s get them to understand how radiometric dating works and how some creationists manipulate the results.
  6. I guess this would lead nicely into Deep Time (Not limited to age of Earth, cover the Time Scale, 85% of Earth’s history is dominated by single celled organisms, etc).
  7. There were more than one Mass Extinction (Dinos weren’t even killed by the biggest)
  8. The Earth has a finite amount of resources and that ALL of our resources (with the exception of solar power I suppose) are directly derived FROM the Earth.
  9. Steno’s Principles of Stratigraphy (Superposition, Lateral Continuity, Inclusions, Cross-cutting relationships, and Original Horizontality)
  10. Faunal Succession


  1. #1 Jon
    March 17, 2009

    As a student with a nearly-complete Geology degree, I am proud to say that I feel like I have all of the points on the various lists down.

    But, the main reason I am posting is in reference to what you said about the geology GREs: My institution has an interesting policy. All Geology seniors are expected to take, and pass, an exam from every geology course they have taken (except intro & whatever geos they are taking that semester). The exams are usually built like this list, with each professor going over what they thought every student in their class should have learned and retained. “Passing” is usually pretty trivial (a 50% with the caveat of getting certain ‘absolutely required’ portions correct counts), and you get three chances at each test, but if you fail all three times (you really don’t know your stuff) you have to retake the course.

    I was wondering 1) if other geology departments did something similiar and 2) if people thought such an exercise was a valuable way to be sure that geo majors did know important lists (like the ones above)

  2. #2 Kim
    March 17, 2009

    Your department is probably responding to demands for more and more assessment data. Colleges and universities are expected, more and more, to show that their programs are effective. My department has avoided using an exit exam so far (though we did discuss it, and we may start using one in the future). Right now, we use our senior thesis presentations – all the majors have to do original research – and have at least one geologist from the community join the department in assessing whether the students have shown that they have met our goals. (Things like understanding the errors associated with data, choosing methods that allow them to test their hypotheses – big nature-of-geoscience type issues, rather than “what’s the difference between stress and strain.”) One benefit is that students get something out of the act that we’re assessing – they get to show off their accomplishments to their friends and their parents, and it’s also a celebration and a rite of passage. Exit exams don’t lead to the same feeling of accomplishment.

  3. #3 Jon
    March 18, 2009

    Probably a fourth of our majors end up doing a senior thesis. We don’t have community geologists come in (mostly because we’re a small town, so the departmental geologists are it), but we do have all of the professors watch and “judge” (though, it is pretty laid back).

    But my department has had these senior exams going on for over 20 years. I agree that the thesis is probably a better avenue to evaluate a student as a scientist simply because any student can cram the night before the exit exams and pass without *knowing* the stuff that they should. However, if I do a senior thesis on paleo, there could be next to no geology in my presentation, so while I can demonstrate that I know about data, error, statistical tests, bias, hypothesis testing and construction and other important science things, I can almost certainly avoid demonstrating any *geology* knowledge.

    But it is very interesting to see other departments do have some kind of final “exam”, and it is also neat to see others still doing a thesis as an undergrad.

  4. #4 Greg Laden
    March 18, 2009

    I would add:

    How to write an effective research proposal (just a mockup for the UG’s)

    How to write an effective contract proposal given an RFP (again, just a mock-up for UGs)

    And, of course, one foreign language and appropriate work in the humanities.

  5. #5 NJ
    March 18, 2009

    You wouldn’t happen to be in Boone, NC, would you Jon?

  6. #6 Laelaps
    March 18, 2009

    It may have more to do with my interest in paleo, but I wish I had learned to read French and German. There is a lot of important work on anatomy of fossils, in particular, that I cannot read until I learn those languages. I do not know if there is a similar trend in geology as a whole (i.e. that there are classic documents only available in another language) but I would imagine that being competent in at least one other language would be a boon in conducting research.

  7. #7 Jon
    March 18, 2009

    I would indeed, NJ. Are you now or were you once at App State?

  8. #8 NJ
    March 18, 2009

    Are you now or were you once at App State?

    As recently as last summer. You may know me as Dr. J…