Porewater redox species and processes in the Black Sea sediments

Konovalov S. K., Luther G. W., Yucel M.

CHEMICAL GEOLOGY, vol.245, pp.254-274, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 245
  • Publication Date: 2007
  • Doi Number: 10.1016/j.chemgeo.2007.08.010
  • Journal Name: CHEMICAL GEOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.254-274
  • Keywords: Black Sea, voltammetric profiling, porewater chemistry, EARLY DIAGENETIC PROCESSES, MARINE-SEDIMENTS, ORGANIC-CARBON, VOLTAMMETRIC MICROELECTRODE, NITRATE REDUCTION, SULFATE REDUCTION, IRON SYSTEMATICS, WATER SEDIMENTS, REACTIVE IRON, IN-SITU
  • Middle East Technical University Affiliated: No

Abstract

During the 2003 KNORR and the 2005 ENDEAVOR cruises to the Black Sea, voltammetric solid-state microelectrode data were collected for the vertical distribution of redox species in porewaters from the upper 200 to 300 mm layer of sediments with nun vertical resolution. We discuss vertical distributions of dissolved sulfide, manganese and iron species in sediments from the oxic, suboxic, anoxic/sulfidic parts of the Black Sea. Results of voltammetric profiling demonstrate many processes governing the porewater chemistry of oxic shelf sediments, suboxic shelf slope sediments, deep anoxic sediments (Unit I), and turbidites in deep anoxic sediments. Sediments from the oxic shelf areas appear to be spatially similar in their porewater chemistry revealing the same sequence of redox species, as elsewhere in the Ocean, except for the lack of manganese. This lack of manganese is explained by its diagenetic remobilization and accumulation in anoxic waters and suboxic sediments.