Geomagnetic paleointensity and directional secular variation at Ocean Drilling Program (ODP) Site 984 (Bjorn Drift) since 500 ka: Comparisons with ODP Site 983 (Gardar Drift)

Abstract

Normalized remanence (relative geomagnetic paleointensity) records for the last 500 kyr can be matched between two Iceland Basin Ocean Drilling Program (ODP) sites (984 and 983) and correlated with other high‐resolution records. Directional secular variation is, however, not easily correlated between sites due to inadequate recording, at these mean sedimentation rates (12–15 cm/kyr), of the characteristic high frequency variability of the directional record. Both sites record the Iceland Basin event at ∼186–189 ka in which the characteristic magnetization component rotates through 180° and back, coincident with a paleointensity low that lasted about 3 kyr. Other Brunhes Chron geomagnetic excursions appear to be manifest as intervals of higher‐amplitude secular variation during lows in paleointensity. There is a tendency for paleointensity lows to correlate with peak interglacials in the oxygen isotope records; however, this does not translate into a correlation between paleointensity and percent carbonate or between paleointensity and magnetic concentration or grain size parameters.