Near mid-ocean ridges seawater circulation through the oceanic lithosphere leads to the formation of hydrothermal deposits and the venting of hydrothermal fluids that can range from ‘black smoker type’ high-T, acidic and sulfide-rich fluids to ‘Lost City type’ low-T, alkaline, and Ca- and H2-rich fluids. These hydrothermal fluids are the result of an extensive chemical exchange between seawater and basement rock lithologies and play a key role in the global geochemical cycles, mineral deposit formation, and in supporting simple life forms within the oceanic lithosphere.
In spring of 2023 a sampling campaign lead by collaborators at NOAA and Oregon State University in Oregon, USA, will conduct a research cruise to the Mid-Atlantic Ridge in search of new hydrothermal systems. In this project, we will investigate hard rock samples and mineral deposits that will be collected during this cruise. The aim and outcome of the research project is largely dependent on the samples that will be recovered during the cruise. Though a focus will be on the mineralogical, petrological and geochemical examination of the samples to constrain the metasomatic processes in the basement rock, fluid-rock interaction temperatures, redox processes and/or the impact of fluid-rock interaction on geochemical cycles such as those of carbon and sulfur. Analytics may involve petrographic characterization of thin sections, Raman spectroscopy, X-ray powder diffraction, electron microprobe analyses and/or laser ablation mass spectrometry.
Note, this project can be started no earlier than July/August 2023. Students interested in this project or in any topic related to alteration of the oceanic lithosphere and fluid-rock interaction processes are welcome to discuss research possibilities with the advisor.
Advisors: Prof. Esther Schwarzenbach
University: FR