Notes:
The final exam will concentrate on material covered since the last exam. It will include basic concepts of geochemical modeling, and will include questions based on your class presentations! A class like this inherently builds on concepts discussed earlier in the semester, so by definition, it is cumulative.
Also, a reminder that the final exam will cover Drever, Chapter 6 (Organic Compounds in Natural Waters).

Example Questions

1. What are delta-D and delta-¹⁸O?
2. Describe and account for the measured delta-D and delta-¹⁸O in meteoric water across North America.
3. Describe a way oxygen isotopes can be used as a paleothermometer.
4. Why do water and steam in geothermal areas usually display a delta-¹⁸O shift, but not a delta-D shift?

2. Weathering of pyrite-bearing shales in North Dakota might lead to the formation of the sulfate mineral
   potassium jarosite, KFe₃(SO₄)₂(OH)₆. Write a balanced equation for the reaction pyrite --> jarosite.
   (Obtain K from the environment).

3. What is pe, and how is it related to Eh? How is it measured?

4. Consider the Eh-pH diagram given in Faure, Fig. 21.1a.
1. Write the chemical reaction between tenorite (CuO) and Cu²⁺ in terms of water and hydrogen ion.
2. Derive the Eh-pH equation for this reaction.
3. What concentration of Cu²⁺ would be found in a lake having an Eh = 0.40 and pH = 7.5?

5. In his classic study of the saprolites formed on granitic gneisses in Minnesota, Goldich observed that potassium feldspars weather more slowly than plagioclase feldspars. What could be a reason for such a phenomenon?