Paper No. 14
Presentation Time: 8:00 AM-12:00 PM
LATE PLIOCENE ICE-RAFTED DEBRIS MASS ACCUMULATION RATES FROM IODP SITE U1359, WILKES LAND CONTINENTAL RISE, ANTARCTICA
An assessment of sediments taken from the IODP (Integrated Ocean Drilling Program) Expedition 318, Core U1359A from the Wilkes Land Rise, has been conducted at a high resolution to determine the response of the East Antarctic Ice Sheet during the mid-late Pliocene. The section of core being studied dates back to ~2.7 to 3.7 Ma. Due to its characteristic similarity to the Earth’s current climate and tectonic configuration, the Pliocene is considered a good indicator as to where the current climate is headed. During the interglacials of the mid-late Pliocene, global mean sea level was about 20m above the present. By looking at records of the late Pliocene, the response of the East Antarctic Ice Sheet as it progresses into the Pliocene-Pleistocene transition can be determined. Samples from this record will be analyzed based on the bulk particle size distributions which were determined using a dual light source laser particle sizer. Calculations of ice rafted debris (IRD) mass accumulation rates (MAR) were constructed using the coarse fraction greater than 125 microns, and corrected for changes in bulk density and biogenic opal content. After analysis of IRD, an additional analysis of microtextures using a scanning electron microscope (SEM) will be conducted on high peaks of IRD. This will test the hypothesis for the origin of the sediments: that they were deposited from icebergs and not turbidity flows.