Age calibrated relative paleointensity for the last 1.5 Myr at IODP Site U1308 (North Atlantic)

Channell, J. E. T. and Hodell, D. A. and Xuan, C. and Mazaud, A. and Stoner, J. S. (2008) Age calibrated relative paleointensity for the last 1.5 Myr at IODP Site U1308 (North Atlantic). Earth and Planetary Science Letters, 274 (1-2). pp. 59-71. ISSN 0012-821X DOI 10.1016/j.epsl.2008.07.005

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Abstract

Integrated Ocean Drilling Program (IODP) Site U1308 (central North Atlantic) records paleomagnetic directional and relative paleointensity (RPI) variations for the last 1.5 Myr, in 110 m of the sediment sequence at a mean sedimentation rate of 7.3 cm/kyr. A detailed benthic oxygen isotope record was combined with RPI to produce an integrated, high-resolution magneto-isotopic stratigraphy for Site U1308. Apart from the well-known polarity reversals in this interval, the Punaruu excursion is recorded at 1092 ka and the Cobb Mountain Subchron in the 1182–1208 ka interval. The paleointensity proxies are determined as slopes of NRM versus ARM and NRM versus ARMAQ (ARM acquisition) with linear correlation coefficients to monitor the quality of the linear fit. The RPI record for Site U1308 is compared with the three other paleointensity records (one from the Western Equatorial Pacific and two from the North Atlantic) that cover the same time interval and have accompanying oxygen isotope records. The Match protocol of Lisiecki and Lisiecki (2002) is used to optimize the correlation of paleointensity records. Beginning with the original (published) age models for each record, the Match routine is used to optimize the RPI correlations to Site U1308, with checks to ensure compatibility with oxygen isotope records. Squared wavelet coherence (WTC) indicates significant improvement in RPI (and oxygen isotope) correlations after matching each RPI record to Site U1308, particularly for periods > 10 kyr. The level of coherence for the Atlantic RPI records and the lower resolution Pacific record implies synchronous global variability (at scales > 10 kyr) that can be attributed to the axial dipole geomagnetic field.

Item Type: Article
Additional Information: Channell, J. E. T. Hodell, D. A. Xuan, C. Mazaud, A. Stoner, J. S.
Uncontrolled Keywords: NIL AREP
Subjects: 01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions: 01 - Climate Change and Earth-Ocean Atmosphere Systems
Journal or Publication Title: Earth and Planetary Science Letters
Volume: 274
Page Range: pp. 59-71
Identification Number: 10.1016/j.epsl.2008.07.005
Depositing User: Sarah Humbert
Date Deposited: 16 Feb 2009 13:01
Last Modified: 23 Jul 2013 10:01
URI: http://eprints.esc.cam.ac.uk/id/eprint/198

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