Undergraduate introductory course in geoscience

Students should be introduced to igneous rocks and the effects of changing pressure and temperature in the subsurface.

We have used this activity as a homework assignment after the topic is introduced in lecture and reading, but it could also be used in class, in lab, or as group work.

Pressure and temperature, igneous rocks/processes, solidus line

Cause and effect; ability to read and understand pressure/temperature graphs

This worksheet helps students think about the cause and effect of pressure/temperature changes in subsurface and how these changes would affect the state of a solid rock. In this worksheet, students are given 6 different scenarios and associated pressure/temperature charts with a solidus line and a starting pressure/temperature point. Scenarios include heating and melting due to a nearby intrusion, diagenesis, decompression melting, cooling of magma at the surface, and adding water to the system. For each scenario, students draw an arrow from the starting point to show how the pressure and temperature would change. For example, students are told that a rock in the subsurface quickly rises towards the surface and melts, so fast that the temperature doesn't change much. A student would then draw a vertical arrow up to show that there is only a change in pressure. There scenarios are chosen to help students better understand the complexities of the subsurface in terms of pressure and temperature.

This worksheet uses the sketch-understanding program with built-in tutor: CogSketch . Therefore, students, instructors, and/or institution computer labs need to download the program from here: http://www.qrg.northwestern.edu/software/cogsketch/. At any point during the worksheet, students can click the FEEDBACK button and their sketch is compared to the solution image. The built-in tutor identifies any discrepancies and reports pre-written feedback to help the student correct their sketch until they are done with the activity. Once worksheets are emailed to the instructor, worksheets can be batch graded and easily evaluated. This program allows instructors to assign sketching activities that require very little time commitment. Instead, the built-in tutor provides feedback whenever the student requests, without the presence of the instructor. More information on using the program and the activity is in the Instructor's Notes.

We have developed approximately two dozen introductory geoscience worksheets using this program. Each worksheet has a background image and instructions for a sketching task. You can find additional worksheets by searching for "CogSketch" using the search box at the top of this page. We expect to have uploaded all of them by the end of the summer of 2016.

CogSketch has a gradebook feature that allows instructors to batch grade worksheets using the defined rubric in the worksheet. Once graded, instructors can also open all the sketches and evaluate student work. Instructions are given in the Instructor's Notes.

Download CogSketch: http://www.qrg.northwestern.edu/software/cogsketch/