Summary: | Understanding the evolution and dynamics of the Antarctic cryosphere, from its inception during the Eocene-Oligocene transition (∼34 Ma) through the significant subsequent periods of likely coupled climate and atmospheric CO2 changes, is not only of major scientific interest but also is of great importance for society. Drilling the Antarctic Wilkes Land margin was designed to provide a long-term record of the sedimentary archives along an inshore to offshore transect of Cenozoic Antarctic glaciation and its intimate relationships with global climatic and oceanographic change. The principal goals were 1. To obtain the timing and nature of the first arrival of ice at the Wilkes Land margin inferred to have occurred during the earliest Oligocene (reflecting Oligocene isotope Event 1), 2. To obtain the nature and age of the changes in the geometry of the prograda- tional wedge interpreted to correspond with large fluctuations in the extent of the East Antarctic Ice Sheet and possibly coinciding with the transition from a wet-based to a cold-based glacial regime, 3. To obtain a high-resolution record of Antarctic climate variability during the late Neogene and Quaternary, and 4. To obtain an unprecedented ultrahigh resolution (i.e., annual to decadal) Holocene record of climate variability. The Wilkes Land drilling program was developed to constrain the age, nature, and paleoenvironment of deposition of the previously only seismically inferred glacial sequences. Drilling the Wilkes Land margin has a unique advantage in that seismic 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. Integrated Ocean Drilling Program Expedition 318, carried out in January-March 2010 (Wellington, New Zealand to Hobart, Australia), occupied seven sites that recovered ∼2000 m of high-quality middle Eocene-Holocene sediments at proposed Sites WLRIS-6A, WLRIS-7A, WLRIS-4A, and ...
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