Environmental Geochemistry

Kevin Theissen

University of St. Thomas
Private four-year institution, primarily undergraduate


This course focuses on geochemical processes that occur at or near the surface which are of particular importance to environmental quality and therefore to humans. During the first few weeks of the course students explore some important principles that serve as the foundations of geochemistry. The next several weeks of the course explore the application of geochemical tools in sediments, soils, and waters. In the final part of the course students work on applying these tools to answer a question of interest as part of a course research project.

Course URL:
Course Size:


Course Context:

This is an upper-division required course for both geology and environmental science (geoscience-track) majors. Prerequisites for the course are an introductory geology and introductory chemistry course. The course has a required three-hour laboratory each week, although the course is often taught in combined lecture-lab format.

Course Goals:

1. Students should be able to define key terms used in geochemistry.
2. Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur hold special importance in the surface environment. Students should be able to identify the important ionic forms of these elements, explain their significance in the environment, and explain how humans have modified the natural global cycles of these elements.
3. Given a geochemical dataset (from lake sediments, soils, or natural waters) students should be able to make reasonable inferences about past or current environmental conditions.
4. Students should be able to carry out selected field and laboratory analyses that are routinely performed in environmental geochemical research.
5. Students should be able to write a logical preliminary interpretation of geochemical data and report the results of a research project in a professional manner.

How course activities and course structure help students achieve these goals:

This course has an emphasis on data analysis and interpretation. Students are frequently challenged to analyze and interpret previously collected geochemical data or data they have collected themselves.
The course also includes a number of hands-on field and laboratory activities designed for students to get practice carrying out environmental monitoring and analysis as practiced by professionals. Both are assessed as laboratory or in-class exercises and are most often scored using rubrics. Student mastery of data interpretation is also assessed using take-home exams and in-class quizzes.

Skills Goals

1. Oral communication
2. Use of Geographic Information Systems software

How course activities and course structure help students achieve these goals:

Students are required to do library research on a topic of interest within environmental geochemistry and then to make a 20 minute presentation on the topic to their instructor and peers. Students are evaluated by the instructor (80% of grade) and peers (20% of grade) and given feedback on a grading rubric to improve their presentation skills. This is preparation for a later presentation on a final research project which is also assessed with a rubric (entirely graded by instructor).
Students get practice using GIS software during the first two weeks of class during a laboratory activity. They are scored on their ability to complete critical tasks. Later, students must apply GIS to answer a research question related to groundwater chemistry in and around a closed landfill site. This is assessed using a grading rubric.


Assessment is done using several different tools. Homework and in-class problem solving activities constitute 15% of the grade. Laboratory activities which often overlap with in-class activities make-up another 20% of the grade and are most often assessed using rubrics. A take-home midterm exam and in-class final quiz constitute 20% of the grade. The largest portion of the grade is a course research project (paper and presentation)which makes up 30%. Finally an oral presentation on an environmental geochemical topic of interest(10%)and class participation and effort (5%) are also included in assessing student learning.