HR: 11:44h
AN: B22A-08 INVITED    [Abstracts]
TI: Deep-Sea Corals in Paleoceanography
AU: * Adkins, J F
EM: jess@gps.caltech.edu
AF: Dept of Geological and Planetary Sciences, Caltech 1200 E California Blvd., Pasadena, CA 91125, United States
AB: Deep-sea corals are a promising new archive of paleoclimate information. The fossil skeletons of scleractinia are closed systems for U-series decay and contain many of the common paleo-tracers used in other biogenic carbonates. However, one of the major limiting factors to their widespread use in solving paleoclimate problems is their perceived paucity in the deep ocean. Relatively recently, several coral focused expeditions with a variety of deep-sea exploration tools including submarines, ROVs, AUVs, dredges, and a variety of sediment cores have demonstrated that large, localized abundances of living and fossil coral material can be recovered. One exciting result of this work is that there are clear temporal and spatial patterns in the fossil record over the last glacial cycle. I will attempt to summarize these results and provide a possible tool for predicting where to find corals more efficiently in the future based on our nascent understanding of their biogeography. I will also describe the on-line use of our fossil coral database at Caltech and how the community can obtain samples from this growing collection. The second largest obstacle to widespread use of deep-sea corals is the classic problem of "vital effects". Modern calibrations for several promising tracers are underway or already published. But there are several groups trying to move beyond establishing these empirical relationships. The corals are a unique laboratory for understanding calcification's contribution to tracer offsets from inorganic equilibrium and may provide important "rules" for unpacking climate information in light of a vital effect overprint. I will show several examples of successes and "failures" on this tracer calibration front.
DE: 0419 Biomineralization
DE: 1115 Radioisotope geochronology
DE: 4815 Ecosystems, structure, dynamics, and modeling (0439)
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting