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Bundled Turbidite Deposition in the Central Pandora Trough (Gulf of Papua) during Last Glacial-Interglacial Cycle: A Potential Link to Millennial Time Scale Climatic Variations and Sea Level Fluctuations

Stephan J. Jorry1, Gianni Mallarino2, Andre W. Droxler1, Luc Beaufort3, Gerald R. Dickens1, Sam J. Bentley4, and Larry C. Peterson5
1 Rice University, Houston, TX
2 PanTerra Geoconsultants B.V, Leiderdorp, Netherlands
3 CEREGE - Université Aix-Marseille III, France
4 Louisiana State University, Baton Rouge, LA
5 University of Miami, Rosenstiel School of Marine and Atmospheric Science, Miami, FL

This study focuses on linking turbidite input in the Central Pandora Trough with sea-level fluctuations and climatic variations at millennium time scale. Two 12-15 m long cores, JPC 33 and 66, collected from the flat bottom part of the through during a 2004 R/V Melville cruise, show the following four distinct sedimentary intervals (from bottom to top): (1) a sandy turbidites dominated interval during late Last Glacial Maximum, (2) an hemipelagic interval with relatively higher carbonate content (foraminifers and coccoliths) during the Boiling/Alroed or first part of the last deglaciation, (3) a terrigeneous-mud rich interval with few thin sandy turbidites corresponding to the Younger Dryas, and (4) the Holocene interval characterized at the bottom by a calciturbidite, triggered during the initial re-flooding of adjacent carbonate platform tops, and overlain by hemipelagic mud with bank derived fine aragonite. A 35 m-long core MD 38 retrieved at the same location as JPC 33 during a 2005 R/V Marion Dufresne cruise and interpreted to represent the last 60 ky shows a series of lighter hemipelagic intervals, resembling the Boiling/Alroed interval in cores JPC 33 and 66, alternating with darker intervals with bundled sandy siliciclastic turbidites. Those series of couplets are interpreted to represent MIS-3 and 2 Dansgard/Oeschger (D/O) cycles. If our interpretation would be correct, bundled sandy turbidites would correspond to the cold intervals of the D/O cycles and, therefore, be triggered by 10-15 m sea-level fluctuations on the adjacent shelf and/or climatic variations at millennial time scale.