International Ocean Discovery Program; Expedition 371 scientific prospectus; Tasman frontier subduction initiation and Paleogene climate

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doi: 10.14379/iodp.sp.371.2016
Author(s): Sutherland, Rupert; Dickens, Gerald R.; Blum, Peter
Author Affiliation(s): Primary:
Victoria University of Wellingon, Department of Geography, Environment, and Earth Sciences, Wellington, New Zealand
Rice University, United States
Texas A&M University, United States
Source: Scientific Prospectus (International Ocean Discovery Program), Vol.371, 39p. Publisher: International Ocean Discovery Program, College Station, TX, United States. ISSN: 2332-1385
Note: In English. 125 refs.
Summary: During International Ocean Discovery Program Expedition 371, we will core and log Paleogene and Neogene sediment sequences within the Tasman Sea. The cores will be analyzed for their sediment composition, microfossil components, mineral and water chemistry, and physical properties. The research will improve our understanding of how convergent plate boundaries form, how greenhouse climate systems work, and how and why global climate has evolved over the last 60 my. The most profound subduction initiation event and global plate-motion change since 80 Ma appears to have occurred in the early Eocene, when Tonga-Kermadec and Izu-Bonin-Mariana subduction initiation corresponded with a change in direction of the Pacific plate (Emperor-Hawaii bend) at ∼50 Ma. The primary goal of Expedition 371 is to precisely date and quantify deformation and uplift/subsidence associated with Tonga-Kermadec subduction initiation in order to test predictions of alternate geodynamic models. This tectonic change may coincide with the pinnacle of Cenozoic "greenhouse" climate. However, paleoclimate proxy data from lower Eocene strata in the southwest Pacific show especially warm conditions, presenting a significant discrepancy with climate model simulations. The second goal is to determine if paleogeographic changes caused by subduction initiation may have led to anomalous regional warmth by altering ocean circulation. Late Neogene sediment cores will complement earlier drilling to investigate the third goal: tropical and polar climatic teleconnections. During Expedition 371, we will drill in a significant midlatitude transition zone influenced by both the Antarctic Circumpolar Current and the Eastern Australian Current. The accumulation of relatively thick carbonate-rich Neogene bathyal strata make this a good location for generating detailed paleoceanographic records from the Miocene through the Pleistocene that can be linked to previous ocean drilling expeditions in the region (Deep Sea Drilling Project Legs 21, 29, and 90; Ocean Drilling Program Leg 189) and elsewhere in the Pacific Ocean.
Year of Publication: 2016
Research Program: IODP2 International Ocean Discovery Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 18 Geophysics, Solid-Earth; Boreholes; Cenozoic; Climate change; Drilling; East Pacific; Expedition 371; Geophysical methods; Geophysical profiles; Geophysical surveys; International Ocean Discovery Program; Kermadec Trench; Marine drilling; Marine sediments; Pacific Ocean; Paleoclimatology; Planning; Plate boundaries; Plate tectonics; Pleistocene; Programs; Quaternary; Sediments; Seismic methods; Seismic profiles; South Pacific; Southeast Pacific; Southwest Pacific; Surveys; Tasman Sea; Tertiary; Tonga Trench; West Pacific
Coordinates: S362000 S261800 E1712100 E1601900
Record ID: 2017001322
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute.