9213907 Helgeson This award will support collaborative research between Harold Helgeson, University of California at Berkeley, and Mariano Valenza, University of Palermo, Italy. The proposed research is an effort to understand better the organobiogeochemisty of geothermal systems and the role that bacteria play in mediating the organic/inorganic interface in geochemical processes. The research will take place at the hot springs in the Aeolian Islands and at the Marcello Carapezza Geochemistry Laboratory on the island of Vulcano and the Istituto di Geochimica dei Fluidi in Palermo, Sicily. The project is an integrated study of the relation between the metabolism of thermobarophilic bacteria in hot springs, the organic/inorganic chemistry of the thermal waters and fumarolic gases, and the composition of the mineralogic environment through which they pass. The Italian research team has intimate familiarity with the geology of the region, together with expertise in sampling and monitoring, and will provide on-site laboratory facilities. The US group brings theoretical and laboratory skills, and familiarity with thermodynamic approaches to studying geothermal systems. ***
