Turbidite vs. Debris Flow: A Class Debate on Deep Water Depositional Systems

Bosiljka Glumac
Smith College
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Debates are a powerful tool for learning and active involvement of students: instead of listening to a lecture on deep water depositional systems the students examine primary literature and debate controversial issues regarding turbidity currents and debris flows.

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An undergraduate required course in sedimentary geology that meets twice as week for 1 hr 20 minutes, and once a week for 2 hrs 50 minutes for a total of 13 weeks and has up to 20 students.

Skills and concepts that students must have mastered

The students are familiar with main characteristics of siliciclastic sedimentary rocks, especially sandstones, and with general concepts of sediment transport and deposition in different environments. To prepare for the debate students read assigned literature.

How the activity is situated in the course

As a stand-alone exercise within a general theme of depositional systems.


Content/concepts goals for this activity

Processes and products of turbidity currents and debris flows within deep water depositional systems

Higher order thinking skills goals for this activity

Critical evaluation and synthesis of ideas from primary literature.

Other skills goals for this activity

Oral presentation (debate skills), writing, literature search.

Description of the activity/assignment

This debate is based on a controversial article by Shanmugam and Moiola on reinterpretation of depositional processes in a classic flysch sequence (1995, AAPG Bulletin, v. 79, p. 672-695), which prompted 5 groups of researchers to write discussions. In preparation for the debate students examine this primary literature and other background information about deep-water sedimentary processes and products. The debate has a formal format with introductory remarks, rebuttals, and final statements by members of the Turbidite and Debris Flow teams.

Determining whether students have met the goals

Check the notes the students took in preparation for the debate;
Monitor quantity and quality of students' participation in the debate;
Read short summary follow up papers.

More information about assessment tools and techniques.

Teaching materials and tips

Other Materials

Supporting references/URLs

There is a huge amount of literature on this topic.

See the actual assignment, where:
P&S = Prothero, D.R., and Schwab, F., 2004, Sedimentary Geology: An Introduction to Sedimentary Rocks and Stratigraphy, 2nd edition: W.H. Freeman and Company, New York, 557 p.

Gani, M.R., 2004, From turbid to lucid: A straightforward approach to sediment gravity flows and their deposits: The Sedimentary Record, v. 2, no. 3, p. 4-8.

Shanmugam, G., 2006, Deep-water processes and facies models: Implications for sandstone petroleum reservoirs: Elsevier, 600 p.