HR: 11:50h
AN: OS32A-07 [Abstracts]
TI: Seasonal to Climate-Scale Variability in the Vertical and Burial Fluxes of Terrigenous Organic Matter
in the Cariaco Basin
AU: * Aceves, H
AF: University of South Carolina, Department of Geological Sciences, Columbia, SC 29208
United States
AU: Goni, M A
EM: goni@geol.sc.edu
AF: University of South Carolina, Department of Geological Sciences, Columbia, SC 29208
United States
AU: Benitez-Nelson, B
AF: University of South Carolina, Department of Geological Sciences, Columbia, SC 29208
United States
AU: Thunell, R
AF: University of South Carolina, Department of Geological Sciences, Columbia, SC 29208
United States
AU: Tappa, E
AF: University of South Carolina, Department of Geological Sciences, Columbia, SC 29208
United States
AU: Muller-Karger, F
AF: University of South Florida, College of Marine Science, St. Petersburg, FL 33701
United States
AU: Lorenzoni, L
AF: University of South Florida, College of Marine Science, St. Petersburg, FL 33701
United States
AU: McIntyre, M
AF: University of South Florida, College of Marine Science, St. Petersburg, FL 33701
United States
AU: Astor, Y
AF: Fundacion La Salle de Ciencias Naturales, Estacion de Investigaciones Marinas de Margarita, Porlamar,
NS 6301
Venezuela
AU: Varela, R
AF: Fundacion La Salle de Ciencias Naturales, Estacion de Investigaciones Marinas de Margarita, Porlamar,
NS 6301
Venezuela
AB:
Biweekly sediment trap samples have been collected continuously since 1995 at multiple depths in the water column as part of
the Cariaco Basin ocean time series. A selected set of samples of sinking particulate matter from 1997 to 1999 have been
analyzed by alkaline CuO oxidation to measure the fluxes of lignin phenol products. Since lignin is uniquely derived from
terrestrial vascular plants, we are using lignin phenols to trace the inputs of terrigenous organic matter at this site. The
results of this study show two seasonal peaks in the flux of lignin phenols of over 0.2 mg/m2/d relative to background
fluxes of about 0.05 mg/m2/d. The timing on one of the peaks of that coincides with the initiation of the main upwelling
period in November-December of each year. A second peak in the flux of lignin phenols was also found during the initiation
of the secondary upwelling event between May and June. The seasonal and inter-annual differences in lignin, and by inference
terrigenous organic matter, fluxes will be discussed in the context of temporal changes in wind, surface salinity,
freshwater runoff and upwelling-controlled biologic productivity. The compositions of the lignin phenols are being
investigated to search for seasonal differences that may help characterize the provenance terrigenous organic matter and help
understand the processes responsible for the measured fluxes. Lignin compositions and burial fluxes from a gravity core
representing 6,000 years of sedimentation are being analyzed to investigate the longer time scale record of terrigenous
organic matter inputs to Cariaco Basin.
DE: 4805 Biogeochemical cycles (1615)
DE: 4806 Carbon cycling
DE: 4850 Organic marine chemistry
DE: 4267 Paleoceanography
DE: 4279 Upwelling and convergences
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting