Paleointensity-assisted chronostratigraphy of detrital layers on the Eirik Drift (North Atlantic) since marine isotope 11

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doi: 10.1029/2007GC001720
Author(s): Evans, Helen F.; Channell, James E. T.; Stoner, Joseph S.; Hillaire-Marcel, Claude; Wright, James D.; Neitzke, Lauren C.; Mountain, Gregory S.
Author Affiliation(s): Primary:
University of Florida, Department of Geological Sciences, Gainesville, FL, United States
Oregon State University, United States
Université du Québec à Montréal, Canada
Rutgers University, United States
Volume Title: Geochemistry, Geophysics, Geosystems - G<sup>3</sup>
Source: Geochemistry, Geophysics, Geosystems - G>3`, 8(11), 23p. Publisher: American Geophysical Union and The Geochemical Society, United States. ISSN: 1525-2027
Note: In English. 57 refs.; illus., incl. 4 tables, sketch map
Summary: Four piston cores collected in 1999 and 2002 from the Eirik Drift (southern Labrador Sea, off SE Greenland) provide paleomagnetic, environmental magnetic, and oxygen isotope records back to marine isotope stage 11. Age models for the cores are based on a combination of planktonic oxygen isotope data, relative geomagnetic paleointensity proxies, and the identification of geomagnetic excursions (Laschamp and Iceland Basin). Environmental magnetic data delineate two distinct detrital signals, interpreted to reflect the behavior of the surrounding ice sheets (Greenland and Laurentide) to orbital- and millennial-scale climate forcing. Broad decimeter-scale intervals of increased magnetic concentration and grain size occur during the early part of interglacial marine isotopic stages (MIS) 1, 5, 7, 9, and 11. Discrete centimeter-scale layers, recognized by magnetic concentration and grain-size sensitive parameters, gamma ray attenuation (GRA) bulk density, and carbonate content, are observed in glacial and interglacial stages as well as during terminations. On the basis of glacial reconstructions on Greenland during the last termination, the broad decimeter-scale coarser-grained intervals can be attributed to detrital influx associated with the retreat of the terrestrial-based Greenland Ice Sheet in the early Holocene. A similar magnetic signal observed within interglacial MIS 5, 7, 9, and 11 indicates similar Greenland Ice Sheet behavior during these time intervals. Two types of centimeter-scale detrital layers are also recognized back to MIS 11. Detrital carbonate (DC) layers reflect predominately ice-rafted debris (IRD) deposition, while the low detrital carbonate (LDC) layers reflect mass movement as evidenced by sharp basal contacts, graded bedding, and traction structures, likely from the Greenland slope. Some detrital layers on Eirik Drift, particularly the DC layers, can be tentatively correlated to detrital layers observed in the central North Atlantic and to those documented on the southern side of the Labrador Sea at Orphan Knoll.
Year of Publication: 2007
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Arctic region; Atlantic Ocean; Carbonates; Cenozoic; Chronostratigraphy; Detrital deposits; Detrital sedimentation; Eirik Drift; Europe; Expeditions 303/306; Glacial environment; Greenland; Greenland ice sheet; Holocene; Iceland; Integrated Ocean Drilling Program; Isotope ratios; Isotopes; Labrador Sea; Laschamp Basin; Laurentide ice sheet; MIS 11; Magnetic minerals; Magnetic properties; North Atlantic; O-18/O-16; Orphan Knoll; Oxygen; Paleomagnetism; Quaternary; Reconstruction; Sedimentation; Stable isotopes; Western Europe
Coordinates: N570000 N590000 W0460000 W0480000
Record ID: 2008109406
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