28 January 2009

Best labs for introductory geology courses?

Posted by Jessica Ball

My department will be restructuring some of their introductory geology labs soon, and I was asked my opinion of the labs that I taught last semester. I was pretty brutal about some of them: they were difficult both to teach and to get the students to understand. When you’re spending most of your time apologizing for the shortcomings of a flow chart that the students are supposed to be using to identify minerals, for example, neither you nor the students are getting much out of the lesson.

There were a number of other issues with the labs, but one of the big questions about the intro labs in general was what were the most valuable labs for different categories of student. The way our courses are likely to be restructured, we may end up with one general geo course and lab for the fall semester, and then two – one for geology majors and one geared more for environmental majors and non-geo-majors – in the spring.

So if you’re going to split up classes that way, how do you create a set of labs that both hooks the potential majors but doesn’t overwhelm the people who are just in the class for a science requirement? How do you make sure the majors are getting instruction in essential, basic skills, but still teach the non-majors something they find interesting and useful? To make things more complicated, how do you do this in a lab that, because of the 300+ person class size, meets every other week – meaning you only have six or seven labs to do this in?

My undergraduate intro geology lab followed this progression:

  • Mineral identification
  • Rock identification, rock types and the rock cycle
  • Structural features of sedimentary rocks (including mapping on aerial photographs, geologic map interpretation, and geologic cross sections)
  • Plate tectonics
  • Geologic interpretation of topo maps, aerial photos, and satellite images (emphasis on fluvial features)
  • Ocean and coastal processes

Looking back on it, it’s both a little scattered and very heavy on what I tend to associate with geology rather than geography or environmental science – rocks and minerals, structure and tectonics, mapping. I remember finding the rock and mineral and mapping labs very useful, but I knew that I wanted to major in geology, and wanted to learn as much as possible as fast as possible.

The lab that I taught last semester went a little differently:

  • Rock descriptions (really basic stuff, not requiring mineral or rock IDs)
  • Mineral identification
  • Sedimentary rock identification
  • Impact cratering
  • Streamflow processes (with stream table)
  • Stratigraphic columns, topo maps and geologic cross sections
  • Folding and faulting

This set of labs reflects some of the research preferences in our department, planetary geoscience and Western NY geology (including the evolution of Niagara Falls and the Niagara Gorge).

I feel like there are pros and cons to each of the sets, but my viewpoint isn’t necessarily what’s going to be good for a nonmajor who needs a science requirement. And whether or not that nonmajor goes on in geology, it’s important for them to get something useful out of the class.

So, how to compromise? It’s a tough process. I’m not the one who gets to make the final decisions, but I think that there are some basic concepts that an intro lab should cover:

  1. Minerals. This is the basis of geology – if you don’t know the minerals, you don’t know the building blocks of the Earth. Everyone coming out of an intro lab should be able to recognize quartz and calcite, as one of the professors here said.
  2. Rock cycle and types. This is a chance to introduce both the rock types and the processes that create them, as well as a few basic rock names in each type. Students can then take this knowledge on to a petrology class (usually taught for igneous and metamorphic rocks, I’ve found) and a sedimentology/stratigraphy class (for the sed rocks).
  3. Surface processes. Weathering and erosion, as well as fluvial features could be included here. I found that my students had very little concept of how sediment was formed, transported, and turned into rocks. The lab that we did with the stream table helped fix some of that, and it was their favorite one; they were the most engaged and spent the most time thinking about what they were observing. This also would have been a fun one to do outside, but it was too cold by the time we got to it.
  4. Atmosphere and weather. I can think of a lot of people who watch the weather forecast every night without having the faintest idea how it’s put together, or the difference between weather and climate, or (for example) why it snows a lot south of Buffalo but not so much north of the city. (This is not the case today, however.) Having a basic knowledge of the structure of the atmosphere and how certain types of weather and climates come about is important for life – you’ve got to deal with weather every day, after all.
  5. The solar system/geology on other planets. With all the great research going on these days into formation and evolution of other planets in the solar system, it would be a shame to skip planetary geology in an intro course. (It’s also a good opportunity to chuck things at sandboxes, which seems to have gone over fairly well in this week’s labs.)
  6. Maps. Absolutely NO ONE should leave a geology or environmental science course without knowing how a map is put together and how to read it. In the age of GPS navigation and Mapquest, it’s honestly shocking how many students I encounter that can’t deal with a paper map. Including topographic and geologic maps in this section would be good too, especially for majors, but also as a way of exposing students to something other than a talking car computer or a fold-out road map. (This would also be a great chance to integrate Geocaching into a lesson and get the students outside.)
  7. Natural hazards/disasters. This would be a favorite of mine just for the chance to talk about volcanoes, but it’s a chance to separate students from what they hear on the news (which is often wrong) and explain what’s really happening when, say, a hundred-year flood occurs, or why an earthquake will or won’t create a tsunami (and what to do if you’re in danger of getting hit by one). It’s also exciting stuff, which is always important if you’re trying to hook people on a major.

Just a few thoughts on what I’d find useful as a beginning geology student, really. I’m sure that the basics would vary depending on the department and who’s qualified to teach certain subjects.

So what would you all, who collectively have much more experience with this sort of thing, want to see in an introductory lab? At some point I might get asked to help decide this for my current department, so your input is greatly appreciated!