In-class Review: Simple vs. Pure Shear


Summary

Quick review worksheet that has students draw a sequence of illustrations of what would occur to a syntectonic quart vein, a pebble conglomerate, a rigid object, and a garnet porphyroblast for pure vs. simple shear. I've used this both as a quiz & as an in-class review.

Used this activity? Share your experiences and modifications

Context

Audience

upper-level structural geology

Skills and concepts that students must have mastered

pure vs. simple shear
understanding of how object orientation impacts deformation
kinematic indicators

How the activity is situated in the course

Brief in-class activity at the start of lecture after kinematic indicators were covered.

Goals

Content/concepts goals for this activity

pure vs. simple shear
development over time of kinematic indicators

Higher order thinking skills goals for this activity

synthesis of ideas

Other skills goals for this activity

drawing

Description and Teaching Materials

Student worksheet handed out at the start of class (have also used as a quiz). Students are encouraged to draw three steps for each type of kinematic indicator for both pure & simple shear and then discussion of the drawings occurs as a class.

review -- pure vs. simple (Microsoft Word 24kB Jun18 12)



Teaching Notes and Tips

I have the students work on this individually and then assign specific students to draw their answers on the board for group discussion. A few mix up simple & pure shear, but in general this works fairly well and the other students tend to critique in a positive fashion. I went with having the students draw the diagrams instead of giving examples because they could ID pictures out of the book, but couldn't ID in the field one year.

Assessment

Discussion is in a small class (<8), so I usually can tell whether or not the students understand basic concepts. A modified problem that asked the students to do a similar procedure was on the final as a retention check.

References and Resources