Integrated Ocean Drilling Program Expedition 318 preliminary report; Wilkes Land glacial history; Cenozoic East Antarctic ice sheet evolution from Wilkes Land margin sediments

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doi: 10.2204/iodp.pr.318.2010
Author(s): Brinkhuis, Hendrik; Escutia Dotti, Carlota; Klaus, Adam; Fehr, Annick; Williams, Trevor; Bendle, James A. P.; Bijl, Peter K.; Bohaty, Steven M.; Carr, Stephanie A.; Dunbar, Robert B.; Gonzàlez, Jhon J.; Hayden, Travis G.; Iwai, Masao; Jimenez-Espejo, Francisco J.; Katsuki, Kota; Kong, Gee Soo; McKay, Robert M.; Nakai, Mutsumi; Olney, Matthew P.; Passchier, Sandra; Pekar, Stephen F.; Pross, Jörg; Riesselman, Christina; Röhl, Ursula; Sakai, Toyosaburo; Shrivastava, Prakash Kumar; Stickley, Catherine E.; Sugisaki, Saiko; Tauxe, Lisa; Tuo Shouting; van de Flierdt, Tina; Welsh, Kevin; Yamane, Masako
Integrated Ocean Drilling Program, Expedition 318, Shipboard Scientific Party, College Station, TX
Author Affiliation(s): Primary:
Utrecht University, Institute of Environmental Biology, Utrecht, Netherlands
Other:
Universite de Granada, Spain
Integrated Ocean Drilling Program, United States
RWTH Aachen University, Federal Republic of Germany
Lamont-Doherty Earth Observatory, United States
University of Glasgow, United Kingdom
University of Southampton, United Kingdom
Colorado School of Mines, United States
Stanford University, United States
Western Michigan University, United States
Kochi University, Japan
Japan Agency for Marine-Earth Science and Technology, Japan
Korea Institute of Geoscience and Mineral Resources, South Korea
Victoria University of Wellington, New Zealand
Daito Bunka University, Japan
University of South Florida-Tampa, United States
Montclair State University, United States
CUNY-Queens College, United States
University of Frankfurt, Federal Republic of Germany
University of Bremen, Federal Republic of Germany
Utsunomiya University, Japan
Geological Survey of India, India
Universitet i Tromso, Norway
Graduate University of Advanced Study, Japan
Scripps Institution of Oceanography, United States
Tongjii University, China
Imperial College London, United Kingdom
University of Queensland, Australia
University of Tokyo, Japan
Source: Preliminary Report (Integrated Ocean Drilling Program), Vol.318, 101p. Publisher: IODP Management International, College Station, TX, United States. ISSN: 1932-9423
Note: In English. 140 refs.
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 progradational 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 WLRIS-5A (Sites U1355, U1356, U1359, and U1361) on the Wilkes Land rise and Sites WLSHE-8A, WLSHE-9A, and ADEL-01B (Sites U1358, U1360, and U1357) on the Wilkes Land shelf at water depths between ∼400 and 4000 m. Together, the cores represent ∼53 m.y. of Antarctic history. Recovered cores successfully date the inferred seismic units (WL-S4--WL-S9). The cores reveal the history of the Wilkes Land Antarctic margin from an ice-free "greenhouse Antarctica," to the first cooling, to the onset and erosional consequences of the first glaciation and the subsequent dynamics of the waxing and waning ice sheets, all the way to thick, unprecedented "tree ring style" records with seasonal resolution of the last deglaciation that began ∼10,000 y ago. The cores also reveal details of the tectonic history of the so-called Australo-Antarctic Gulf (at 53 Ma) from the onset of the second phase of rifting between Australia and Antarctica, to ever subsiding margins and deepening, all the way to the present continental and ever widening ocean/continent configuration. Tectonic and climatic change turned the initially shallow broad subtropical Antarctic Wilkes Land shelf into a deeply subsided basin with a narrow, ice-infested margin. Thick Oligocene and notably Neogene deposits, including turbidites, contourites, and larger and smaller scaled debris mass flows witness the erosional power of the waxing and waning ice sheets and deep ocean currents. The recovered clays, silts, and sands and their microfossils also reveal the transition of subtropical ecosystems and a vegetated Antarctica into sea ice-dominated ecosystems bordered by calving glaciers.
Year of Publication: 2010
Research Program: DSDP Deep Sea Drilling Project
IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 20 Geophysics, Applied; Algae; Antarctic ice sheet; Antarctica; Bathymetry; Biostratigraphy; Boreholes; Carbon dioxide; Cenozoic; Chemostratigraphy; Chronostratigraphy; Climate change; Continental margin; Continental shelf; Contourite; Cores; DSDP Site 269; Deep Sea Drilling Project; Diatoms; East Antarctic ice sheet; Expedition 318; Expeditions; Foraminifera; Geophysical methods; Geophysical profiles; Geophysical surveys; Glacial environment; Glaciation; IODP Site U1355; IODP Site U1356; IODP Site U1357; IODP Site U1358; IODP Site U1359; IODP Site U1360; IODP Site U1361; Interglacial environment; Invertebrata; Leg 28; Lithostratigraphy; Magnetostratigraphy; Marine sediments; Microfossils; Nannofossils; Paleo-oceanography; Paleoclimatology; Paleoenvironment; Paleotemperature; Palynomorphs; Plantae; Protista; Quaternary; Sediments; Seismic methods; Seismic profiles; Seismic stratigraphy; Southern Ocean; Surveys; Tertiary; Turbidite; Wilkes Land
Coordinates: S750000 S750000 E1250000 E1250000
N631800 N662500 E1690000 E1402500
Record ID: 2010048006
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