International Ocean Discovery Program; Expedition 378 scientific prospectus; South Pacific Paleogene climate

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doi: 10.14379/iodp.sp.378.2018
Author(s): Thomas, Deborah J.; Röhl, Ursula; Childress, Laurel
Author Affiliation(s): Primary:
Texas A&M University, College of Geosciences, College Station, TX, United States
Other:
University of Bremen, Germany
Source: Scientific Prospectus (International Ocean Discovery Program), Vol.378, 27p. Publisher: International Ocean Discovery Program, College Station, TX, United States. ISSN: 2332-1385
Note: In English. 61 refs.
Summary: International Ocean Discovery Program (IODP) Expedition 378 is designed to recover the first comprehensive set of Paleogene sedimentary sections from a transect of sites strategically positioned in the South Pacific to reconstruct key changes in oceanic and atmospheric circulation. These high southern-latitude sites will provide an unparalleled opportunity to add crucial new data and geographic coverage to existing reconstructions of Paleogene climate. As the world's largest ocean, the Pacific Ocean is intricately linked to major changes in the global climate system. Previous drilling in the low-latitude Pacific Ocean during Ocean Drilling Program (ODP) Legs 138 and 199 and Integrated Ocean Drilling Program Expeditions 320 and 321 provided new insights into the mechanisms of the climate and carbon system, productivity changes across the zone of divergence, time-dependent calcium carbonate dissolution, bio- and magnetostratigraphy, the location of the Intertropical Convergence Zone, and evolutionary patterns for times of climatic change and upheaval. Expedition 378 in the South Pacific Ocean uniquely complements this work because appropriate highlatitude records are unobtainable in the Northern Hemisphere of the Pacific Ocean. To optimize the recovery of Paleogene carbonates buried under red clay sequences at present latitudes of 40°-52°S and enable a full range of paleoceanographic proxy-based investigations, Expedition 378 will drill a transect of sites primarily situated along magnetic Anomaly 25n on ∼56 Ma crust. Additional sites are located on 40 Ma crust (Anomaly 18). The drilling strategy will also redrill the sedimentary record at Deep Sea Drilling Project (DSDP) Site 277 to obtain a continuous record of a previously spot-cored, classic Paleogene high-latitude site and provide a crucial, continuous record of the shallow subantarctic South Pacific Ocean from the Paleocene to late Oligocene. These new cores and data will significantly contribute to the challenges of the "Climate and Ocean Change: Reading the Past, Informing the Future" theme of the IODP Science Plan (How does Earth's climate system respond to elevated levels of atmospheric CO2? How resilient is the ocean to chemical perturbations?). Furthermore, Expedition 378 will provide material from the far South Pacific Ocean in an area with no previous scientific drilling as part of a major regional slate of expeditions in the Southern Ocean to fill a critical need for high-latitude climate reconstructions. The operational plan is to occupy seven primary sites (with two proposed alternate sites) along an east-west transect to recover the most complete sedimentary succession possible, which includes coring three holes at each site with wireline logging operations at the two deepest penetration sites. Basement will be tagged in at least one of the holes at each site.
Year of Publication: 2018
Research Program: DSDP Deep Sea Drilling Project
IODP2 International Ocean Discovery Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 20 Geophysics, Applied; Boreholes; Campbell Plateau; Cenozoic; Chronostratigraphy; DSDP Site 277; Deep Sea Drilling Project; Depositional environment; Drilling; Expedition 378; Expeditions; Geophysical methods; Geophysical profiles; Geophysical surveys; International Ocean Discovery Program; Leg 29; Lithofacies; Lithostratigraphy; Marine drilling; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Paleogene; Paleotemperature; Planning; Reconstruction; Sea-surface temperature; Seismic methods; Seismic profiles; South Pacific; Southwest Pacific; Surveys; Tertiary; West Pacific
Coordinates: S530000 S400000 W1340000 W1661200
Record ID: 2018011065
Copyright Information: GeoRef, Copyright 2018 American Geosciences Institute.