Abstract
Arctic late Paleocene–early Eocene paleoenvironments with special emphasis on the Paleocene-Eocene thermal maximum (Lomonosov Ridge, Integrated Ocean Drilling Program Expedition 302)
Palaeoecology, Laboratory of Palaeobotany and Palynology, Institute of Environmental Biology, Utrecht University, Utrecht, Netherlands
Center for Marine Environmental Sciences, Bremen University, Bremen, Germany
Department of Marine Biogeochemistry and Toxicology, Royal Netherlands Institute for Sea Research, Den Burg, Texel, Netherlands
Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
Palaeoecology, Laboratory of Palaeobotany and Palynology, Institute of Environmental Biology, Utrecht University, Utrecht, Netherlands
Department of Marine Biogeochemistry and Toxicology, Royal Netherlands Institute for Sea Research, Den Burg, Texel, Netherlands
Department of Marine Biogeochemistry and Toxicology, Royal Netherlands Institute for Sea Research, Den Burg, Texel, Netherlands
Department of Earth Sciences, Utrecht University, Utrecht, Netherlands
Palaeoecology, Laboratory of Palaeobotany and Palynology, Institute of Environmental Biology, Utrecht University, Utrecht, Netherlands
We reconstruct the latest Paleocene and early Eocene (∼57–50 Ma) environmental trends in the Arctic Ocean and focus on the Paleocene-Eocene thermal maximum (PETM) (∼55 Ma), using strata recovered from the Lomonosov Ridge by the Integrated Ocean Drilling Program Expedition 302. The Lomonosov Ridge was still partially subaerial during the latest Paleocene and earliest Eocene and gradually subsided during the early Eocene. Organic dinoflagellate cyst (dinocyst) assemblages point to brackish and productive surface waters throughout the latest Paleocene and early Eocene. Dinocyst assemblages are cosmopolitan during this time interval, suggesting warm conditions, which is corroborated by TEX86′-reconstructed temperatures of 15°–18°C. Inorganic geochemistry generally reflects reducing conditions within the sediment and euxinic conditions during the upper lower Eocene. Spectral analysis reveals that the cyclicity, recorded in X-ray fluorescence scanning Fe data from close to Eocene thermal maximum 2 (∼53 Ma, presence confirmed by dinocyst stratigraphy), is related to precession. Within the lower part of the PETM, proxy records indicate enhanced weathering, runoff, anoxia, and productivity along with sea level rise. On the basis of total organic carbon content and variations in sediment accumulation rates, excess organic carbon burial in the Arctic Ocean appears to have contributed significantly to the sequestration of injected carbon during the PETM.
Received 9 May 2007; accepted 20 August 2007; published 7 February 2008.
Citation: (2008), Arctic late Paleocene–early Eocene paleoenvironments with special emphasis on the Paleocene-Eocene thermal maximum (Lomonosov Ridge, Integrated Ocean Drilling Program Expedition 302), Paleoceanography, 23, PA1S11, doi:10.1029/2007PA001495.
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