FEC Recovery for Shipboard Scientist Duties of Dr Steven Bohaty for IODP Expedition 318 (Wilkes Land)

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The Expedition 318 drilling program in the offshore Wilkes Land region of Antarctica is designed to constrain the age, nature, and paleoenvironment of deposition of the previously only seismically inferred glacial sequences. Determining the chronostratigraphy of the Wilkes Land sediments, which is at present nonexistent, is critical to ground-truth the existing glacial-stratigraphic and ice sheet volume models for this margin. Ice sheet models suggest that the Wilkes Land margin became glaciated in the later stages of East Antarctic glaciation; therefore, it is an area presumed to be more sensitive to future temperature changes. Drilling the Wilkes Land margin has a unique advantage in that Unconformity WL-U3, inferred to separate preglacial strata below from glacial strata above in the continental shelf, can be traced to the continental rise deposits, allowing sequences to be linked from shelf to rise. Because strata below and above the 'glacial onset' unconformity can be sampled at relatively shallow penetration depths, the record of the onset of glaciation can be obtained during a single drilling expedition from two depositional environments, the shelf foreset (proposed Sites WLSHE-07, WLSHE-09, WLSHE-10, and WLSHE-11) and the abyssal plain hemipelagic (proposed Site WLRIS-02A) strata. Constraints on the age and nature of the glacial sequences in these section is essential to provide age constraints for models of Antarctic ice sheet development.