(Same as Atmospheric and Oceanic Sciences CM237B.) Lecture, three hours. Recommended requisite: course CM214A. Broad overview of aquatic geomicrobiological processes in diverse environmental settings (e.g., sediments, microbial mats, water column, wetlands, cold seeps, hydrothermal vents, deep biosphere), and how these processes drive element cycling on Earth. Concurrently scheduled with course CM114B. S/U or letter grading.