HR: 0800h
AN: PP51C-0617    [Abstracts]
TI: A Giant Arctic Freshwater Pond at the end of the Early Eocene; Implications for Ocean Heat Transport and Carbon Cycling
AU: * Brinkhuis, H
EM: H.Brinkhuis@bio.uu.nl
AF: Laboratory of Palaeobotany and Palynology, Department of Biology,Utrecht University, Budapestlaan 4, Utrecht, 3584 CD Netherlands
AU: Schouten, S
EM: schouten@nioz.nl
AF: Royal Netherlands Institute for Sea Research (NIOZ), Department of Marine Biogeochemistry and Toxicology, PO Box 59, Den Burg, 1790 AB Netherlands
AU: Collinson, M E
EM: m.collinson@gl.rhbnc.ac.uk
AF: 3Dept. Geology, Royal Holloway University of London, Royal Holloway College Road, Egham, TW20 0EX United Kingdom
AU: Sluijs, A
EM: a.sluijs@bio.uu.nl
AF: Laboratory of Palaeobotany and Palynology, Department of Biology,Utrecht University, Budapestlaan 4, Utrecht, 3584 CD Netherlands
AU: Sinninghe-Damst‚, J S
EM: damste@nioz.nl
AF: Royal Netherlands Institute for Sea Research (NIOZ), Department of Marine Biogeochemistry and Toxicology, PO Box 59, Den Burg, 1790 AB Netherlands
AU: Sinninghe-Damst‚, J S
EM: damste@nioz.nl
AF: Department of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht, 3584 CD Netherlands
AU: Dickens, G R
EM: jerry@esci.rice.edu
AF: Department of Earth Sciences, Rice University, 6100 Main Street, Houston, TX 77005 United States
AU: Huber, M
EM: huberm@purdue.edu
AF: Earth and Atmospheric Sciences Department and the Purdue Climate Change Research Center, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47906 United States
AU: Cronin, T M
EM: tcronin@usgs.gov
AF: USGS National Center, 12201 Sunrise Valley Drive, Reston, VG 20192 United States
AU: Bujak, J P
EM: jonathan@bujakmudge.com
AF: Bujak Research International, 105 North Park Drive, Blackpool, FY3 8NE United Kingdom
AU: Stein, R
EM: rstein@awi-bremerhaven.de
AF: Alfred-Wegener-Institute for Polar and Marine Research, Columbusstrasse, 27568, Bremerhaven, D-2000 Germany
AU: Eldrett, J S
EM: info@ichron.com
AF: Ichron Ltd, 5 Dalby Court, Gadbrook Business Park, Northwich, Cheshire, CW9 7TN United Kingdom
AU: Harding, I C
EM: ich@noc.soton.ac.uk
AF: School of Ocean & Earth Science, Southampton Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH United Kingdom
AU: Sangiorgi, F
EM: f.sangiorgi@bio.uu.nl
AF: Laboratory of Palaeobotany and Palynology, Department of Biology,Utrecht University, Budapestlaan 4, Utrecht, 3584 CD Netherlands
AU: Sangiorgi, F
EM: f.sangiorgi@bio.uu.nl
AF: Royal Netherlands Institute for Sea Research (NIOZ), Department of Marine Biogeochemistry and Toxicology, PO Box 59, Den Burg, 1790 AB Netherlands
AB: In the last decades remains of the free-floating, fresh water fern Azolla have been found in unusually high abundances in basal middle Eocene (~48.5 Ma) marine sediments deposited in all Nordic seas. While generally taken to signal some `freshwater input', their source and significance were not determined. Through palynological and organic geochemical analyses of unique cores obtained from unprecedented Arctic Ocean drilling (IODP 302 - ACEX) we show that the brackish surface conditions that prevailed in the Arctic Ocean through the late Paleocene and early Eocene culminated in the deposition of laminated organic rich deposits yielding huge amounts of remains of Azolla. This, plus e.g., low diversity dinoflagellate assemblages, and concomitant low BIT values, indicates in-situ Azolla growth, and that the surface of the Arctic Ocean episodically resembled a giant fresh water pond over an interval altogether lasting ~800,000 years. The Arctic Basin thus constituted the main source of the freshwater pulses found elsewhere, reaching as far south as the southern North Sea.TEX86-derived surface temperatures were 13-14§C before and after the Azolla interval and only 10§C during the event, which may be related to obstruction of pole ward ocean heat transport and/or increased carbon burial.
DE: 4825 Geochemistry
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
DE: 4912 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 1615, 4805)
DE: 4930 Greenhouse gases
DE: 4954 Sea surface temperature
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005