NORTHEASTERN MINNESOTA – As part of the Cutting Edge workshop on Teaching Mineralogy, Petrology, and Geochemistry, I had the opportunity to participate in a field trip to the Midcontinent Rift System in northeastern Minnesota. You can imagine how exciting this was to an Ohio-based (outcrop-deprived) petrologist! Here’s a quick tour of some of the spectacular stops on the trip:
Keweenawan diabase dike intruding slates and greywackes of the Thomson Formation.
Layering in the Lower Troctolite Zone of the Duluth Complex.
Folding in Archean greywackes of the Lake Vermilion Formation.
Multiple generations of folding in the Soudan-type Banded Iron Formation.
Basaltic pillow in the Ely Greenstone with exquisitely preserved glassy textures in the hyaloclastite rims.
Lichen-covered columnar joints in basalt flows of the North Shore Volcanic Group.
A large plagioclase crystal (showing striations) from an anorthosite xenolith.
Learning about the fantastic geology of northeastern Minnesota was only one of our primary goals. The other was to discuss strategies for field-based teaching and learning. There are countless reasons for bringing our students to the field, including two that I consider most important: (1) the field challenges students to exercise their higher-order critical thinking skills (making observations and dealing with complexity); and (2) the field inspires students to learn and be curious of the natural world. The field trip provided an opportunity for “a collection of North America’s greatest geoscience educators”* to share effective teaching ideas for helping students achieve these goals. I’ve compiled a short list of useful tips that I took away from the trip:
- Enhance the social learning environment – Encourage students to learn something about each other by asking them to line up in order of first name or longitude of their place of birth. Establishing a community enhances peer-to-peer learning, which is a powerful instructional practice in the field.
- Set and assess goals – For every field trip (and every stop), set specific learning goals, then ask How do we accomplish these goals? How do we know we’ve accomplished these goals? Learning goals and teaching activities will vary with audience and setting. Consider the following example: the learning goal of one particular field trip stop was to observe and describe volcanic features of an outcrop of mafic metavolcanic flows. For the activity, we were provided with an outline of the outcrop and asked to map the distribution of volcanic features from one end to the other. At the end, we compared maps and discussed similarities and differences. The conversation helped us describe the volcanic features we used to define the different units and to determine the stratigraphic “up” direction.
- Connect the classroom to the field – We’ve all held large maps against the vans to use as visual aids when explaining the geologic setting, but why not laminate poster-sized photomicrographs or phase diagrams to enhance the discussion? By directly applying field observations to concepts they’ve learned in class, students will learn to transfer content knowledge to different settings.
- Don’t neglect the affective domain – An honorable learning goal is to inspire a sense of awe in students. We certainly had several stops that were breathtakingly beautiful and “reminded all of us why we love geology.” I’m sure most of us can recall a particular field experience that motivated us to pursue geology as a major. Sometimes, it’s the “fun” stops that have the greatest impact.
- Technology can enhance student learning – One person suggested recording podcasts that students could listen to in the vans between field trip stops. Another person mentioned that smartphones or iPads could be used to take and annotate images of outcrops, which can be loaded onto a wiki later for a collaborative learning project. (The idea probably works equally well for paper photos). On the field trip, we used a portable XRF to measure and compare the compositions of different rock units.
The BIF was one of the stunning outcrops where the field trip leaders allowed us to be excited and explore before trying to discuss the geology.
Geologists and their toys: playing with the pXRF.
If you have ideas for effective field-based teaching practices or would like to share your experiences, please comment!
*Directly quoted response from field trip leader J. Goodge when a passer-by asked “What is this?”
