Expedition 302 summary

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doi: 10.2204/iodp.proc.302.101.2006
Author(s): Backman, Jan; Moran, Kathryn; McInroy, David; Brinkhuis, Henk; Clemens, Steven; Cronin, Thomas; Dickens, Gerald Roy; Eynaud, Frédérique; Gattacceca, Jérôme; Jakobsson, Martin; Jordan, Richard W.; Kaminski, Michael; King, John; Koc, Nalan; Martinez, Nahysa C.; Matthiessen, Jens; Moore, Theodore C., Jr.; Onodera, Jonaotaro; O'Regan, Matthew; Palike, Heiko; Rea, Brice; Rio, Domenico; Sakamoto, Tatsuhiko; Smith, David C.; Stein, Ruediger; St. John, Kristen E. K.; Suto, Itsuki; Suzuki, Noritoshi; Takahashi, Kozo; Watanabe, Mahito; Yamamoto, Masanobu
Integrated Ocean Drilling Program, Expedition 302 Scientists, College Station, TX
Author Affiliation(s): Primary:
Stockholm University, Department of Geology and Geochemistry, Stockholm, Sweden
Other:
University of Rhode Island, United States
British Geological Survey, United Kingdom
Utrecht University, Netherlands
Brown University, United States
U. S. Geological Survey, United States
Rice University, United States
Université de Bordeaux I, France
University of Aix-Marseille III, France
Yamagata University, Japan
University College London, United Kingdom
Polar Environmental Center, Norway
Boston University, United States
Alfred Wegener Institute for Polar and Marine Research, Federal Republic of Germany
University of Michigan, United States
Kyushu University, Japan
University of Southampton, United Kingdom
University of Aberdeen, United Kingdom
University of Padua, Italy
Japan Agency for Marine-Earth Science and Technology, Japan
James Madison University, United States
University of Tsukuba, Japan
Tohoku University, Japan
Institute of Geoscience, Japan
Hokkaido University, Japan
Norwegian Polar Institute, Norway
Volume Title: Proceedings of the Integrated Ocean Drilling Program; Arctic Coring Expedition (ACEX); Expedition 302 of the mission-specific drilling platform from and to Tromso, Norway; sites M0001-M0004; 7 August-13 September 2004
Volume Author(s): Backman, Jan; Moran, Kathryn; McInroy, David; Brinkhuis, Henk; Clemens, Steven; Cronin, Thomas; Dickens, Gerald Roy; Eynaud, Frédérique; Gattacceca, Jérôme; Jakobsson, Martin; Jordan, Richard W.; Kaminski, Michael; King, John; Koc, Nalan; Martinez, Nahysa C.; Mattiessen, Jens; Moore, Theodore C., Jr.; Onodera, Jonaotaro; O'Regan, Matthew; Palike, Heiko; Rea, Brice; Rio, Domenico; Sakamoto, Tatsuhiko; Smith, David C.; Stein, Ruediger; St. John, Kristen E. K.; Suto, Itsuki; Suzuki, Noritoshi; Takahashi, Kozo; Watanabe, Mahito; Yamamoto, Masanobu
Source: Proceedings of the Integrated Ocean Drilling Program; Arctic Coring Expedition (ACEX); Expedition 302 of the mission-specific drilling platform from and to Tromso, Norway; sites M0001-M0004; 7 August-13 September 2004, Jan Backman, Kathryn Moran, David McInroy, Henk Brinkhuis, Steven Clemens, Thomas Cronin, Gerald Roy Dickens, Frédérique Eynaud, Jérôme Gattacceca, Martin Jakobsson, Richard W. Jordan, Michael Kaminski, John King, Nalan Koc, Nahysa C. Martinez, Jens Mattiessen, Theodore C. Moore, Jr., Jonaotaro Onodera, Matthew O'Regan, Heiko Palike, Brice Rea, Domenico Rio, Tatsuhiko Sakamoto, David C. Smith, Ruediger Stein, Kristen E. K. St. John, Itsuki Suto, Noritoshi Suzuki, Kozo Takahashi, Mahito Watanabe and Masanobu Yamamoto; Integrated Ocean Drilling Program, Expedition 302 Scientists, College Station, TX. Proceedings of the Integrated Ocean Drilling Program, Vol.302, 22p. Publisher: IODP Management International, Washington, DC, United States. ISSN: 1930-1014
Note: In English. 22 refs.; illus., incl. sects., 3 tables, sketch map
Summary: The first scientific drilling expedition to the central Arctic Ocean was completed in September 2004. Integrated Ocean Drilling Program Expedition 302, Arctic Coring Expedition (ACEX), recovered sediment cores to 428 meters below seafloor (mbsf) in water depths of ∼1300 m, 250 km from the North Pole. Expedition 302's destination was the Lomonosov Ridge, hypothesized to be a sliver of continental crust that broke away from the Eurasian plate at ∼56 Ma. As the ridge moved northward and subsided, marine sedimentation occurred and continues to the present, resulting in what was anticipated from seismic data to be a continuous paleoceanographic record. The elevation of the ridge above the surrounding abyssal plains (∼3 km) ensured that sediments atop the ridge were free of turbidites. The primary scientific objective of Expedition 302 was to continuously recover this sediment record and to sample the underlying sedimentary bedrock by drilling and coring from a stationary drillship. The biggest challenge during Expedition 302 was maintaining the drillship's location while drilling and coring in 2-4 m thick sea ice that moved at speeds approaching 0.5 kt. Sea-ice cover over the Lomonosov Ridge moves with one of the two major Arctic sea-ice circulation systems, the Transpolar Drift, and responds locally to wind, tides, and currents. Until now, the high Arctic Ocean Basin, known as "mare incognitum" within the scientific community, had never before been deeply cored because of these challenging sea-ice conditions. Initial results reveal that biogenic carbonate is present only in the Holocene-Pleistocene interval. The upper 198 mbsf represents a relatively high sedimentation rate record of the past 18 m.y. and is composed of sediment with ice-rafted debris and dropstones, suggesting that ice-covered conditions extended at least this far back in time. Details of the ice type (e.g., iceberg versus sea ice), timing, and characteristics (e.g., perennial versus seasonal) await further study. A hiatus occurs at 193.13 mbsf, spanning a 25 m.y. interval from the early Miocene to the middle Eocene between ∼18 Ma and 43 Ma. The sediment record during the middle Eocene is of dark, organic-rich biosiliceous composition. Isolated pebbles, interpreted as ice-rafted dropstones, are present down to 239 mbsf, well into this middle Eocene interval. Around the lower/middle Eocene boundary an abundance of Azolla spp. occurs, suggesting that a fresh and/or low-salinity surface water setting dominated the region during this time period. Although predrilling predictions based on geophysical data had placed the base of the sediment column at 50 Ma, drilling revealed that the uppermost Paleocene to lowermost Eocene boundary interval, well known as the Paleocene/Eocene Thermal Maximum (PETM), was recovered. During the PETM, the temperature of the Arctic Ocean surface waters exceeded 20°C. Drilling during Expedition 302 also penetrated into the underlying sedimentary bedrock, revealing a shallow-water depositional environment of Late Cretaceous age.
Year of Publication: 2004
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Arctic Coring EXpedition; Arctic Ocean; Biostratigraphy; Boreholes; Cenozoic; Chemostratigraphy; Cores; Cretaceous; Density; Downhole methods; Expedition 302; Expeditions; Gamma-ray spectra; Geochemistry; Geophysical methods; Geophysical profiles; Geophysical surveys; Hydrochemistry; IODP Site M0002; IODP Site M0003; IODP Site M0004; Integrated Ocean Drilling Program; Lithostratigraphy; Lomonosov Ridge; Mesozoic; Physical properties; Pore water; Sedimentary rocks; Sedimentation; Sedimentation rates; Seismic methods; Seismic profiles; Shear strength; Spectra; Surveys; Temperature; Upper Cretaceous; Well logs
Coordinates: N875100 N875600 E1393300 E1361000
Record ID: 2007087836
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