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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.

This dissertation presents the results of chronostratigraphic studies on marine sediment cores from three Oceans. Using a combination of magnetic stratigraphy, biostratigraphy and cycle stratigraphy it is possible to produce chronostratigraphies that exceed the resolution of any individual technique. In the North Atlantic, environmental magnetic records from Eirik Drift, south of Greenland, record detrital signals related to the melting of the Greenland and Laurentide Ice Sheets. The detrital layer stratigraphy has been placed in a paleointensity-assisted chronostratigraphic template, based on paleointensity and stable isotope data, to enhance correlation of detrital layers across the North Atlantic region. In the central Atlantic, on Gardar Drift, correlation of a benthic oxygen isotope record to the Greenland and Vostok Ice cores has placed cores from the drift on a revised GISP chronology. A stack of relative paleointensity records was developed and placed on the revised GISP chronology. In marine isotope stage 3, a benthic isotope record appears to record changes in bottom water temperature that are coeval with magnetic grain size changes. IODP Site U1313 from the North Atlantic produced a high-resolution polarity stratigraphy and relative paleointensity record between 2.5 and 6.0 Ma. This is one of a handful of paleointensity records for this interval. Cycles in magnetic susceptibility allowed agecalibration by correlation to a benthic oxygen isotope stack. Sediment cores from the Pacific Ocean produced excellent magnetic stratigraphies, and cycles in the sediment allowed astronomic calibration of reversal boundaries. Based on the correlation of planktonic foraminifer datums to the magnetic stratigraphy at ODP Site 1208, a new planktonic foraminifer zonation for the northwest Pacific Ocean can be precisely correlated to polarity chrons and astronomically calibrated ages. Numerous paleomagnetic excursions are tentatively identified for the first time in Pacific sediments. Oxygen isotope records from the Late Miocene (9.3-11.2 Ma) at ODP Site 1092 (South Atlantic) allowed astronomic calibration of ages of reversal boundaries and three polarity excursions within Chron 5. This is the first time astronomically calibrated ages have been assigned to these polarity excursion chrons and indicate a duration for the excursions of 3-4 kyrs.