Contemporaneous early diagenetic formation of organic and inorganic sulfur in estuarine sediments from St. Andrew Bay, Florida, USA

Details Contemporaneous early diagenetic formation of organic and inorganic sulfur in estuarine sediments from St. Andrew Bay, Florida, USA Contemporaneous early diagenetic formation of organic and inorganic sulfur in estuarine sediments from St. Andrew Bay, Florida, USA

Jul 1996

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996gecoa..60.2325b&link_type=abstract

Geochimica et Cosmochimica Acta, vol. 60, Issue 13, pp.2325-2332

Computer Science

5

Scientific paper

Estuarine sediment samples were collected from nine stations in St. Andrew Bay near Panama City, Florida, USA. Contrasting grain size and varying concentration of organic carbon allowed a comparative study of the relationships among organic degradation processes, sulfur cycling, and diagenetic removal of dissolved sulfide produced by bacterial sulfate reduction. Abundance and sulfur isotopic composition were determined for dissolved sulfide, dissolved sulfate, pyrite, humic-acid sulfur, fulvic-acid sulfur, and elemental sulfur. Presence of free dissolved sulfide and enrichment in 34 S of porewater sulfate in samples from organic-rich, muddy sediments of St. Andrew Bay indicate high rates of sulfate reduction and anoxic conditions below 5 mm depth. Such conditions are not reflected in samples from organic-poor, sandy, near-shore sediments collected from highly productive areas occupied by seagrass beds. In this estuarine system, pyrite and fulvic-acid sulfur are the largest sinks for sulfide produced by bacterial sulfate reduction. Strong correlation between abundances of pyrite and fulvic-acid sulfur suggests coincident formation in the uppermost 10 cm of sediment. Large differences in isotopic composition between these two species and consistent enrichment in 34 S of the fulvic-acid fraction, however, indicate two different reaction pathways. Abundance and sulfur isotopic composition of humic-acid and fulvic-acid sulfur suggest that organic sulfur is derived from mixing between (1) 34 S-depleted sulfur with an unknown oxidation state that was recycled from bacterial hydrogen sulfide and (2) 34 S-enriched sulfur interpreted as primary biosynthetic sulfur originally assimilated from dissolved sulfate. Samples taken from sandy sediment localities where aquatic vascular plants are rooted in the anoxic zone show a strong depletion in 34 S in the fulvic-acid sulfur fraction suggesting recycled hydrogen sulfide as the dominant source of organic sulfur.

Affiliated with

Also associated with

No associations

Rating

Contemporaneous early diagenetic formation of organic and inorganic sulfur in estuarine sediments from St. Andrew Bay, Florida, USA does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Contemporaneous early diagenetic formation of organic and inorganic sulfur in estuarine sediments from St. Andrew Bay, Florida, USA, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Contemporaneous early diagenetic formation of organic and inorganic sulfur in estuarine sediments from St. Andrew Bay, Florida, USA will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1117324