Rolling Rocks (Not the Beer!) - How Nature Shapes Stone

Scott Brande, University of Alabama at Birmingham
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The transformation of massive rock to sediment (i.e., gravel) is a process of nature not confined to Earth. A qualitative introduction to the forces of weathering and erosion that control the development of fragment shape in gravel provides insight into fundamental processes spanning planetary bodies in our solar system. A few images and video snips provide visual evidence that students observe to learn about these sedimentary processes. In a short exercise that may be used in lecture or a laboratory session, students make observations, write descriptions, discuss issues with peers, and use hypotheses to extrapolate terrestrial sedimentary science to another planetary body. Questions are arranged in order of, and span, the hierarchy of cognitive skills. This design should make this exercise accessible to students across a variety of levels, from non-science to geoscience majors.

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Undergraduate course in introductory physical geology for non-majors and majors.

Skills and concepts that students must have mastered

Observation, description, one lecture on weathering and erosion, and an introduction to sedimentary rock.

How the activity is situated in the course

A short, in-class, exercise, with handout that is collected after completion.


Content/concepts goals for this activity

accurate description (in words) of gravel particle shape from images and video; quick sketch of particle shapes; understanding of how gravel shape is controlled by forces of weathering and erosion

Higher order thinking skills goals for this activity

application of observed dynamic processes of transportation to interpretation of static images

Other skills goals for this activity

This exercise is what I call a "multimodal" response exercise, because it requires observation of images and video, attention to detail, the writing of descriptions and explanations in words, the sketching of a few particle shapes, the discussing of ideas with nearby peers, and the extrapolation of terrestrial processes to another planet.

Description and Teaching Materials

Students are given individual paper copies of the handout. The instructor shows images in color projected onto a screen in the classroom or laboratory, and also plays and projects the short video snips while students watch, write, discuss, and complete questions on the handout.
'Student handout for Rolling Rock Exercise' (Microsoft Word 2007 (.docx) 3.9MB Jun6 17)
'Student handout for Rolling Rock Exercise' (Acrobat (PDF) 815kB Jun6 17)

Teaching Notes and Tips

Not much to say. Web access to Youtube is required for playing the video snips. Suitable as a cognitive break from lecture. Designed to be cognitively challenging. Specific video snips chosen to be engaging and illustrative of processes. Some explanation narrative provides "real-world" example of gravel transportation triggered by earthquake. Shortened URL in last question hides identity of location for final images so that students may not immediately jump to inferences about weathering and erosion on Mars, but will be informed of this when the instructor clicks the web link to project images on NASA's web site.


All questions completed. Essential observations recorded as descriptions. Some sketches recorded (but artistic quality not assessed). Instructor observes level of student peer-to-peer interactions/discussion. Explanations extend interpretations of observed processes.

References and Resources

All web resources required are included as hyperlinks in the document.