Jorgensen, B. B.. Max Planck Institute for Marine Microbiology, bjoergen@mpi-bremen.de
Boettcher, M. B.. Max Planck Institute for Marine Microbiology, mboettch@mpi-bremen.de
Neretin, L. Max Planck Institute for Marine Microbiology, lneretin@mpi-bremen.de
Weber, A. Max Planck Institute for Marine Microbiology, aweber@mpi-bremen.de

 
GEOCHEMISTRY OF SULFATE-METHANE AND SULFIDE-IRON DIFFUSION FRONTS IN BLACK SEA SEDIMENTS
 
The geochemistry of sulfur, iron and methane was studied in five-meter deep gravity cores from slope and basin sediments of the western Black Sea. A consistent pattern of pore water diffusion gradients was found at all stations, created by sulfur-rich marine deposits overlying iron-rich limnic deposits. Sulfate reached ca. 3 m down into the sediment and peaks of sulfate reduction were found at the sediment-water and sulfate-methane interfaces. At the latter, a hydrogen sulfide maximum occurred from which sulfide diffused both upwards and downwards. A narrow band of black hydrotroilite and magnetic, coarse-crystalline greigite formed ca. 1 m deeper. A deep sink for sulfide has general implications for the sulfur geochemistry of marine sediments.
 
Day: Friday, Feb. 5
Time: 10:45 - 11:00am
Location: Sweeney Center
 
Code: CS63FR1045S