Microbial Weathering of Ocean Basalts back to Research
To date, it has been challenging to determine the extent to which microbes are involved in low temperature (<100°C) basalt weathering reactions, although textural, chemical and biological evidence suggests that bacterial activity may be widespread. Research in the Tebo lab focuses on the role of iron- and manganese-oxidizing bacteria, siderophore-producing bacteria, and other bacteria in basalt weathering. Our research is designed to identify which microorganisms are involved in the initial stages of basalt weathering, their identity and modes of metabolic activity, and how transient these microbial communities may be. The project is a blend of field and laboratory work combining field exposure experiments with bacterial cultivation and molecular microbiological methods. The field work is being conducted on Loihi seamount and Puna Ridge, the submarine extension of the Kilauea Volcano (Hawaii), and on Vailulu’u, a seamount hotspot located near American Samoa. We sample basalts, vent fluids and ambient seawater, as well as deploy and retrieve basalt and mono-mineralogic charges, using research submersibles. Molecular methods are used to identify the major colonizers of the basalts. Physiological experiments in the lab focus on measuring the rates and mechanisms of basalt alteration.