ConcepTest: Cross-Sections of Plate Boundaries
Question:
The map below shows the plate configurations along the western margin of North America. Which of the four diagrams on the right best represents a cross section through the outer layers of Earth along the line X-Y?
Student Responses:
The correct response is A.
Percentage of students choosing this answer. (% Before Discussion/% After Discussion):
a. (40%/60%)
b. (35%/40%)
c. (10%/0%)
d. (15%/0%)
in a small (< 60 students) physical geology lab section
Instructor's comments:
I asked for students to explain their reasoning. Those that answered B didn't notice or understand the divergent boundary off the coast. This question was a good way to discuss the reason for the convergent boundary off of WA coast and transform boundary of the CA coast.
If you would like to help acquire more Before and After statistics for this example, please contact the authors (see link at top of page).
