Broadly adaptable for any level; have used in upper-level undergraduate and graduate level.

Understanding of plate tectonics and general subsidence mechanisms.

This activity is part of a larger arc of lessons aimed at building "scale literacy" for sedimentary geology, where students are expected develop a sense of high, characteristic, and low rates and scales of sedimentary processes; this exercise occurs as part of the discussion of accommodation creation.

Help students develop a sense geodynamic subsidence rates characteristic of different tectonic settings.

Comparison of different tectonic settings and synthesis of understanding about geodynamic processes.

Graph reading. Working in groups.

As part of a lecture discussing accommodation creation, students are asked to study subsidence curves from different tectonic settings. The first make observations of their assigned figure alone, then discuss their observation with other students assigned the same figure. Following that discussion the students rearrange groups and share their findings with students who looked at other figures. The class ultimately works together to assemble a table of characteristic subsidence rates and patterns in different tectonic settings.

Preparation: Make copies of basin-subsidence figures from Xie and Heller, 2009 - only one figure per page, and remove the basin title and figure caption. You will only need enough copies so each student gets one figure, with the number of students with each figure divided roughly equally among the class (e.g., in a class with 15 students, there will be 3 students assigned to each of the 5 figures). Make copies of the location map from Xie and Heller (enough for at least one map per group of 5).

Distribute the figures instructing the students to take a few minutes on their own to make note of the range of rates, scales, durations, and character of subsidence histories represented in their figure. After a few minutes, ask the students to pair up with others who had their figure and compare notes.

When the groups have had a chance to discuss their figure, rearrange the students into new groups of where there is one representative for each figure in each group. Distribute maps to the new groups and ask the groups to compare figures by building a table of the range of and characteristic subsidence magnitude, subsidence duration, subsidence rates and character of subsidence through time (e.g., liner, increasing, decreasing, episodic.). With this information and the map, students should work to reason which tectonic setting each figure represents.

Finish with a whole-class discussion and assign Xie and Heller for reading homework.
Xie and Heller, 2009 (Acrobat (PDF) 280kB Jun6 14)
Figures for subsidence exercise (Microsoft Word 2007 (.docx) 708kB Jun6 14)

Introducing (or reminding) students about concepts like flexure, isostasy, thermal subsidence is helpful for getting the students started.