Environmental Geochemistry

Carey Gazis,
Central Washington University


This environmental geochemistry course examines two perspectives on geochemistry: a scientific discipline with its own basic unanswered questions and a set of tools for answering questions in other geologic subdisciplines. The course covers topics including biogeochemical cycles, the influence of rocks and soils on water chemistry, and the use of isotopes as environmental tracers. It includes a class project addressing a local environmental topic (e.g., trace metal concentrations near a local waste site, or the effect of land use on soil chemistry).

Course Size:

Course Format:
Students enroll in one course that includes both lecture and lab. The lecture and the lab are both taught by the professor.

Institution Type:
Public four-year institution, primarily undergraduate

Course Context:

This is a 400/500-level course. It usually consists of 10-15 undergraduate students and 5-8 Masters students. The students are mostly Geology and Environmental Geology majors, with a few Chemistry or Biology majors. The course has a required laboratory and has a prerequisite of two terms of introductory chemistry.

Course Content:

see attached syllabus

Course Goals:

Course Outcomes:
Upon successful completion of Environmental Geochemistry (GEOL 425/525):
1. Global geochemical cycles -- Students can describe geochemical cycles of water and carbon in terms of their principle reservoirs, residence times in those reservoirs and fluxes between major reservoirs. They can differentiate between long-timescale processes (such as silicate weathering) and short-timescale processes (such as anthropogenic increase in atmospheric CO2).
2. Equilibrium thermodynamics -- Students comprehend and can describe in their own words the laws of thermodynamics. They understand how the equilibrium constant of a reaction can be derived from expressions for chemical potential and Gibbs free energy.
3. Laboratory skills -- Students have basic laboratory skills necessary to carry out a supervised geochemical study (e.g. can perform Gram titration of waters in field, can collect water samples using clean methods).
4. Water and soil chemistry -- Students have basic knowledge of water and soil chemistry, controls on pH, cation and anion concentrations.
5. Acid-base chemistry -- Students have a basic knowledge of acids and bases, their properties and behavior. Students understand the relative strengths of acids and bases and related equilibria.
6. Knowledge of different techniques -- Given an environmental geochemical problem, students are aware of geochemical techniques (isotopes, trace elements, etc.) which might be used to address that problem.
7. Current topics -- Students are aware of current topics of research in environmental geochemistry and can read and critically discuss a research article.

Course Features:

A critical assignment is the class project in which students design a research project and collect data as a class and then write individual reports.

Course Philosophy:

The class projects allows the students to analyze a bigger data set and work collaboratively on many aspects of research. It is easier to control the sampling strategy and data quality than if they were doing individual or group projects. The quality of the research and resultant data set is better.


By reading their research reports.


CWU Environmental Geochemistry course syllabus (Acrobat (PDF) 88kB May31 13)

Teaching Materials:

References and Notes:

Principles of Environmental Geochemistry by Nelson Eby
I liked the material that was covered and the order in which it was presented.