HR: 1340h
AN: U43A-0820    [Abstracts]
TI: High-resolution Holocene Paleomagnetic Secular Variation Records from Iceland: Towards Marine - Terrestrial Synchronization
AU: * Olafsdottir, S
EM: saediso@hi.is
AF: Institute of Earth Sciences and Dept of Geosciences, University of Iceland, Reykjavik, 101 Iceland
AU: Stoner, J S
EM: jstoner@coas.oregonstate.edu
AF: COAS, Oregon State University, Corvallis, OR 97331 United States
AU: Geirsdottir, A
EM: age@hi.is
AF: Institute of Earth Sciences and Dept of Geosciences, University of Iceland, Reykjavik, 101 Iceland
AU: Miller, G H
EM: gmiller@colorado.edu
AF: INSTAAR and Geological Sciences, University of Colorado, Boulder, CO 30309-0450 United States
AU: Channell, J E
EM: jetc@geology.ufl.edu
AF: Dept of Geological Sciences, University of Florida, Gainesville, FL 32611 United States
AB: Paleomagnetism offers the unique potential for marine - terrestrial correlation. Here we explore this potential using the paleomagnetic secular variation records recovered from Icelandic Holocene marine and lacustrine sediments. Long cores with sedimentation rates > 1 m/kyr were collected from two Icelandic lakes using the GLAD-200 drill rig in 2003: Haukadalsvatn HAK03 (65° 03.06 N, 21° 37.83 W, water depth 39 m, length 30 m) and Hvitarvatn HVT03 (64° 38.29 N, 19° 51.57 W, water depth 31 m, length 12 m). Marine cores were collected in 1999 during the IMAGES cruise on the R/V Marion Dufresne II from the NW shelf of Iceland. Core MD99-2264 is from the Djupall trough with Holocene sedimentation rates of 0.5 m/kyr (66° 40.74 N, 24° 11.76 W, water depth 230 m, length 38 m) and core MD99-2265 from an inlet fjord, Jokulfirdir with Holocene sedimentation rates of 1 m/kyr (66° 16.63 N, 22° 51.47 W, water depth 93 m, length 18 m). The paleomagnetic records were studied from u-channel samples measured on the longcore cyrogenic magnetometers at the Paleomagnetism Laboratories at University of Florida and at the University of California, Davis. HAK03 preserves a strong (NRM > 0.5 A/m), stable (MAD < 1), low coercivity (< 10% of the NRM remained after 60 mT AF demagnetization) magnetization consistent with magnetite as the remanence carrier. HVT03 also preserves a strong (NRM > 0.5 A/m) and stable (MAD < 2) magnetization, though the coercivity is significantly higher (30-50% of the NRM remains after 60 mT AF demagnetization), resulting from finer grain sizes and more felsic source rocks. The Holocene sections of the marine cores (MD99-2264 and 2265) also preserve a strong (NRM > 0.1 A/m), stable (MAD < 1.5) and low coercivity (< 10% of the NRM remained after 60 mT AF demagnetization) magnetization. Initial correlations identify at least 5-10 major inclination and declination features, which are distinctive and correlative among the four independent PSV records. These are used to synchronize events between these different environments. The PSV recorded by the lacustrine and marine sediments show characteristics in inclination and declination that can be correlated to the well-dated PSV curve (MD99-2269) which serves as the PSV template for this region.
DE: 1105 Quaternary geochronology
DE: 1600 GLOBAL CHANGE
DE: 7221 Paleoseismology (8036)
DE: 8177 Tectonics and climatic interactions
DE: 8408 Volcano/climate interactions (1605, 3309)
SC: Union [U]
MN: Fall Meeting 2005