Quaternary magnetic and isotope stratigraphy at IODP sites U1306 and U1305 (Eirik Drift, SW Greenland)

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http://abstractsearch.agu.org/meetings/2012/FM/GP41B-03.html
Author(s): Channell, J. E. T.; Wright, J. D.; Mazaud, Alain; Stoner, J. S.; Hillaire-Marcel, Claude
Author Affiliation(s): Primary:
University of Florida, Geological Sciences, Gainesville, FL, United States
Other:
Rutgers University, United States
CEA-CNRS, France
Oregon State University, United States
Universite du Quebec a Montreal, Canada
Volume Title: AGU 2012 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2012; American Geophysical Union 2012 fall meeting, San Francisco, CA, Dec. 3-7, 2012. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: Quaternary stratigraphies for IODP Sites U1305 and U1306 (Eirik Drift, off SW Greenland) are facilitated by combined use of planktic oxygen isotopes, relative paleointensity (RPI), and the magnetic polarity record, back to ∼1.5 Ma. RPI is now a well-tested stratigraphic tool for the Quaternary of the North Atlantic, and the Eirik Drift records can be matched to calibrated RPI stacks such as PISO. Benthic foraminifers are too scarce, at both sites, to permit benthic isotope records. A stratigraphy based on correlation of RPI to PISO can be used to access perturbations in the planktic isotope record due to meltwater affects at glacial terminations. The combined oxygen-isotope/RPI stratigraphy indicates contrasting sedimentation-rate patterns at Site U1305 (3460 m water depth) and Site U1306 (2272 m water depth). According to the resolved stratigraphies, meltwater signals in the planktic isotope record are manifest by premature (age-shifted) apparent glacial "terminations" particularly well resolved at Site U1305. At Site U1306, sedimentation rates are elevated during glacial isotopic stages (up to 40 cm/kyr) and reduced during interglacials to about 10 cm/kyr. At Site U1305, the sedimentation-rate pattern is converse, with interglacial sedimentation rates reaching 50 cm/kyr and glacial sedimentation rates often less than 10 cm/kyr. At Site U1306, volume susceptibility and magnetic grain size are elevated during peak glacials whereas these same parameters are elevated during interglacials at Site U1305. We attribute these contrasts to the vigor and location of the Western Boundary UnderCurrent (WBUC), the interaction of bathymetry with the WBUC, and variations in sediment supply from east Greenland.
Year of Publication: 2012
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; Cenozoic; Clastic sediments; Drift; Eirik Drift; Expedition 303; Expeditions 303/306; IODP Site U1305; IODP Site U1306; Integrated Ocean Drilling Program; Isotope ratios; Isotopes; Marine sedimentation; Marine sediments; North Atlantic; Northwest Atlantic; O-18/O-16; Oxygen; Paleomagnetism; Quaternary; Sedimentation; Sedimentation rates; Sediments; Stable isotopes
Coordinates: N572800 N572900 W0483200 W0483200
N581400 N581400 W0453800 W0453900
Record ID: 2014093125
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