The oceanic crust and upper mantle undergo significant hydrothermal alteration upon interaction with seawater along mid-ocean ridge spreading centers. During this process sulfur and carbon are incorporated into the altered lithologies and are eventually transported into Earth’s interior through subduction. Both sulfur and carbon are essential components in the Earth’s system as they occur in mineral phases in rocks, are abundant in ocean water, occur in trace amounts in the atmosphere, and are major constituents of biogenic processes. Thus, it is essential to understand the cycling of these elements between different Earth reservoirs.
This project will include field work in exhumed ocean lithosphere lithologies in the Swiss Alps (e.g., Saas-Zermatt Zone, Antrona ophiolite, Platta Nappe). Carbon and sulfur isotope signatures will be used to track the source and speciation of C and S during ocean floor to subduction zone processes. The analytical work will include petrographic characterization of rock samples and the analyses of C and S isotope ratios. Additional analytical methods may include electron microprobe analyses, scanning electron microscopy, Raman spectroscopy, X-ray powder diffraction, and/or laser ablation mass spectrometry.
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 Esther Schwarzenbach.
Advisors: Prof. Esther Schwarzenbach
University: FR