Biogeochemical Cycling and Authigenic Mineral Formation in Suboxic Tropical Mobile Mud Belts

ABSTRACT OCE-0219919 The coastal mud wave at Sinnamary, French Guiana and the clinoform muds in the Gulf of Papua are systems wherein massive suboxic diagenesis takes place and represent sites that effectively remineralize terrestrial and marine organic matter. Two scientists from the State University of New York at Stony Brook plan to continue their research efforts in these tropical mobile mud belts to refine their interpretations of the biogeochemical processes at these sites, determine the interaction between the mobile mud belts and surrounding sedimentary environments, complete laboratory experiments on authigenesis and microbial metabolic activity and develop comparative models of these two regions. In French Guiana, the PIs hope to assess the properties of sedimentary material which becomes entrained into the suboxic mobile zone during wave migration and mangrove erosion. In the Gulf of Papua, this team of scientists will sample across the shelf from the mangrove fringe to the foreset region at 60m water depth during the NW Monsoon and SE Trade Period. The goals of the project as this site are the following: (1) quantify and model cycling rates, reaction pathways, reactive material source, sedimentary storage of biogenic debris and nutrient remineralization in the top 1-3m; (2) determine relative role of unsteady versus steady sedimentation processes in maintaining the biogeochemical properties across the region: (3) characterize the associations and interactions of benthic biological communities with particular biogeochemical/physical regimes; and (4) obtain sedimentary authigenic mineral suites and biogenic trace records for environmental reconstruction. The team of scientists will collaborate with scientists from the University of Washington whom will be looking at the sediment dynamics of the Gulf of Papua, as well as Australian scientists.