12.491 | Fall 2007 | Graduate
Biogeochemistry of Sulfur


Course Meeting Times

Lectures: 1 session / week, 1.5 hours / session


Permission of instructor


This course is designed for advanced undergraduate and graduate students with an interest in using primary research literature to discuss and learn about current research around sulfur biogeochemistry and astrobiology. During the regular class session, we will analyze two to three papers in a discussion-based format. Each class will conclude with a brief outline of the following week’s class introduced by the instructors, or at the beginning of the class for sessions lead by guest lecturers.


  • Origin of mass-dependent, mass-independent sulfur isotope fractionation
  • Global sulfur cycles, past and present
  • Role of sulfur in organic diagenesis, and petroleum generation
  • Sulfur isotope biosignatures in early Earth rocks and Martian meteorites
  • Diagnostic lipids for sulfidic oceans
  • Molecular biology of sulfur metabolisms
  • Sulfur isotope record and the early Earth’s atmosphere
  • Dimethylsulfides and other atmospheric sulfur gases

Textbook and General Readings

Brimblecombe, P. “The Global Sulfur Cycle.” Treatise on Geochemistry 8 (2003): 645-682.

Canfield, D. E. “Biogeochemistry of Sulfur Isotopes.” Reviews in Mineralogy and Geochemistry 43 (2001): 609-636.

Ohmoto, H., and M. B. Goldhaber. “Sulfur and Carbon Isotopes.” In Geochemistry of Hydrothermal Ore Deposits. Edited by H. L. Barnes. New York: John Wiley & Sons, 1997. ISBN: 9780471571445.


1 Introductory remarks: course structure and content
2-3 Calculation of equilibrium mass-dependent isotope effects
4 Sulfur and oxygen isotope fractionation in biological systems
5 Sulfidic ocean: evidence and implications
6 Proterozoic
7 Diagnostic lipids for ocean euxinia
8 Dimethylsulfides and atmospheric sulfur cycle
9 Discussion topic selected by participants
10 Molecular biology of sulfur
11 Discussion topic selected by participants
12 Organic sulfur and preservation of lipid biomarkers
13 Discussion about selected topics


One term paper for a selected subject will be required for 50% of the credit, and the remaining 50% will be based upon the basis of contribution to the discussion session.

Course Info
As Taught In
Fall 2007