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. Peterson^5
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.