HR: 1340h
AN: PP33A-1543    [Abstracts]
TI: The influence of organic carbon flux on benthic foraminiferal proxies
AU: * Corliss, B H
EM: bruce.corliss@duke.edu
AF: Duke University, Division of Earth and Ocean Sciences, Nicholas School of the Environment and Earth Sciences, Durham, NC 27708 United States
AU: Sun, X
EM: shawn.sun@walgreens.com
AF: Duke University, Division of Earth and Ocean Sciences, Nicholas School of the Environment and Earth Sciences, Durham, NC 27708 United States
AU: Brown, C W
EM: christopher.w.brown@noaa.gov
AF: National Oceanic and Atmospheric Administration, Office of Research and Applications, College Park, MD 20742 United States
AU: Showers, W J
EM: wshowers@ncsu.edu
AF: North Carolina State University, Department of Marine, Earth and Atmospheric Sciences, Raleigh, NC 27607 United States
AB: During the last 30 years, deep-sea benthic foraminifera have been widely used in reconstructing environmental conditions in the deep sea. Initial suggestions of faunal-water mass associations were never substantiated and, instead, organic carbon flux was identified as a primary influence on species and assemblage patterns. Organic carbon flux also impacts the chemistry of deep water masses and is reflected in the stable isotopic and trace element composition of a number of deep-sea taxa. The timing of delivery of organic carbon can also have an affect on foraminiferal chemistry. Carbon-13 data of Holocene Epistominella exigua from the North Atlantic show a 0.9 per mil change over 60 degrees of latitude that can be correlated to seasonality of productivity, based on a comparison of SeaWIFS satellite imagery. Seasonality and mean annual primary productivity do not affect the carbon-13 of Planulina wuellerstorfi in the North Atlantic, although P. wuellerstorfi exhibits significant variability. Our results suggest that the carbon-13 of E. exigua in conjunction with P. wuellerstorfi can be used to reconstruct seasonality of primary productivity. These findings raise the possibility that other geochemical proxies influenced by particle flux from the surface may be affected by periodic flux events that create phytodetritus layers and change the chemistry of the microhabitats occupied by some benthic foraminiferal species. Existing studies suggest that organic carbon flux and seasonality of flux influence both faunal and geochemical signals from benthic foraminiferal. These relationships can be used to reconstruct primary productivity and seasonality, in addition to deep-water circulation, and illustrate the importance of incorporating ecological information in the interpretation of geochemical data from deep sea taxa.
DE: 4804 Benthic processes, benthos (0408)
DE: 4870 Stable isotopes (0454, 1041)
DE: 4944 Micropaleontology (0459, 3030)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005