Project Details
Projekt
Sulphur isotopic investigation of dissolved and solid sulphur phases in fluids, mineral precipitates, sediments and rock samples from the Mid-Atlantic Ridge
Applicant
Professor Dr. Harald Strauß
Subject Area
Oceanography
Term
from 2005 to 2010
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 16318840
The ultimate objective of this research project is a qualitative and quantitative understandingof sulphur cycling at mid-ocean ridges. Abundance and isotope results obtained so far fordifferent sulphur forms in liquid and solid samples from the two principal study sites (i.e.Logatchev hydrothermal field and southern MAR sites) provide evidence for inorganic(leaching of mantle sulphur and high-temperature seawater sulphate reduction) andbiological (reduction of sulphate and elemental sulphur) cycling of a diverse mix of sulphurcompounds, including metastable thiols. Current estimates, in part based on preliminarymultiple sulphur isotope data, point to a 30% contribution from recycled seawater sulphate tothe overall sulphur budget of hydrothermal fluids.Future work will focus on two different aspects: (a) the determination of multiple sulphurisotopes at different spatial resolutions in order to (i) quantify the different sulphurcontributions (i.e. recycled seawater sulphate, leached mantle sulphur, biological sulphurcycling, and (ii) identify the details of sulphur isotope fractionation at mid-ocean ridgehydrothermal settings, and (b) the quantification of sulphur metabolism and associatedisotope effects based on culture experiments with organisms cultivated from the vent sitesstudied.
DFG Programme
Priority Programmes
