Geology professor Charles Onasch of Bowling Green State University suggests a lesson in observation and analysis:
ANALYSIS OF SIDEWALK FRACTURES
Summary
Using fractures in sidewalks as an analog for natural outcrops, students learn to make systematic observations, measure the orientation and location of fractures, manipulate and analyze data, and consider some kinematic and dynamic questions regarding the origin and significance of fractures.
(Thanks to investigator Scott Langill for bringing this to our attention.)