Constraining sediment source geology and exhumation through conglomerate modeling and lag time

Barbara Carrapa
University of Wyoming
Author Profile


This assignment is part of the Tectonics and Sedimentation course (graduate to post graduate level) and is aimed at this enhancing students' capability of independently assessing complex scientific issues.

Used this activity? Share your experiences and modifications



This exercise is designed for graduate to post graduate students taking a course in Tectonics and Sedimentation (2hrs per week). This course requires students to have taken physical geology; mineralogy and sedimentary petrology, and stratigraphy.

Skills and concepts that students must have mastered

Students are able to do basic college algebra. They also should be capable of comprehending scientific papers.

How the activity is situated in the course

This activity is designed as part of a series of lab exercises and problem sets in a Tectonics and Sedimentation course. However, this activity can also be used as a stand-alone exercise.


Content/concepts goals for this activity

Allow the students to:
1. Better understand the relationship between source exhumation and sedimentation.
2. Strengthen and develop their interpretational skills by reading papers and applying the new acquired information to simple examples.
3. Be able to determine the contribution of the sediment source to the detritus and calculate lag time and exhumation rates.
4. Learn how to interpret thermocronological ages recorded in the sedimentary record.

Higher order thinking skills goals for this activity

This exercise requires students to critically analyze and interpret data; includes basic statistics mathematical analysis.

Other skills goals for this activity

This assignment will require students to write their solutions and interpretations by using their newly acquired skills and by applying knowledge learned via papers reading.

Description of the activity/assignment

In order to be able to undertake this assignment, students will not only have to follow and interact in class but also read and understand papers at home. After a first simple question on the tectonic style of the mountain range students will have to apply what they learn from the paper from DeCelles and Giles (1996) and Graham et al. (1986), assigned to read as homework, to answer the first set of examples. Consequently, I have developed a second-part exercise designed to help students understand the relationship between source and sediments; they will use data provided in the exercise to constrain the rates and patterns of source exhumation. In order to answer the second-part exercise students will have to read a suite of papers on detrital thermochronology (Bernet et al., 2002; Carrapa et al., 2003); this will enhance their capability of independently assess complex scientific issues. They will also have to apply simple equations to calculate the rate of source exhumation (through the concept of lag time).

Determining whether students have met the goals

Learning outcomes are assessed based on the following:
1. Active participation of the students in classes.
2. Ease with which students can solve simple problems in class (lab) exercises.
3. Ability of students to apply notions and formulas learnt though homework reading to future lab exercises involving exhumation pattern and rates.
4. Quantitative assessment through graded course work (50%) and a final 3 hour written exam (50%).

More information about assessment tools and techniques.

Download teaching materials and tips

Other Materials

Supporting references/URLs

Lecture notes are available for students under the University of Potsdam website.