Image From: http://www.monmouth.com/~cathygrim/mystery.htm

Geologic Methods

The power of observation

I used this exercise to begin the very first lecture of the semester in an introductory geology course for non-majors. More specifically, the course was taught at the community college level in a program inside San Quentin State Prison.

Originally, we were apprehensive about teaching a murder mystery to students who may have committed a murder themselves. However, the students became very interested and excited in the exercise, enthusiastically participating. Once we established a list of agreed upon observations, they began arguing back and forth about theories and their interpretation of the evidence. The exercise was an overwhelming success. Depending upon the age level of your students, a murder mystery may or may not be appropriate. Either way, don't glorify the violence. In fact, one possible scenario is that the man is not dead, but just spilled coffee, tripped and fell.

I did the exercise in the following order:

Have students look at the photo for 1 minute silently by themselves.
Ask students to list observations about the image. Write them down on the board as students give them. Be very clear about the difference between observations and interpretation and don't write any interpretations on the board.
When you have collected all the observations, ask the class if everyone agrees with these observations.
Now the fun begins. Ask for students to volunteer their interpretation about the sequence of events that happened.
Let chaos reign for a few minutes as students argue competing theories.
Summarize the different interpretations, highlighting the geologic principles that each theory depends upon (shown below).
Show the geologic images from the Powerpoint presentation.
Put the murder mystery image up and go over the geologic principles again.
End class without giving them an answer about what really happened.

The power of this exercise is that it exposes students to the main goals of geology and even some of the fundamental principles in a setting that they can understand. Solving the detective story introduces students to both OBSERVATIONAL skills and the fundamental principals of Geology. Geology is a lot like detective work.You use common sense and some basic fundamental principles. These principles are often introduced at the beginning of a first year geology class. Here, I introduce them in a non-geologic context and then show images of how they apply geologically.

For example, you might find the some of the following observations that lead to a discussion of important geologic concepts:

Wrinkled Rug = Original Horizontality
Man on top of rug on top of floor = Superposition
Coffee spilled onto papers = Cross-cutting relations
Missing telephone = Unconformity (we know something used to be there)
Broken wristwatch & Calendar = Absolute dating of events
Coffee spilled on shirt gives us relative timing of coffee and shirt, but nothing about the relative timing of coffee spilling and murder.
Spilled Coffee not due to open window because the direction of coffee spill is not consistent with the wind direction. = Inferences based on Physical Processes and the Laws of Physics
Man still wearing watch and wedding ring (look closely), so it was not a robbery = Common Sense (an invaluable skill in Geology!)
In general, we come on a scene with a lot of missing information and unknowns. We reconstruct the facts by inferences derived from knowledge of process (the way things should work) and keen observation, but allowing for interesting, unexpected, and exceptional events as well (as long as they are POSSIBLE).

There is no correct answer to this murder mystery! Let your students' creativity go wild. My students have a difficult time accepting that I won't give them "the real story" about what happened. This is also a good message about the way in which geology works.

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