RELATIVE GEOMAGNETIC PALEOINTENSITY AND DELTA-O-18 AT ODP SITE-983 (GARDAR DRIFT, NORTH-ATLANTIC) SINCE 350 KA

At ODP Site 983, relative geomagnetic paleointensity and planktic and benthic delta(18)O records have been acquired for the last 350 kyr. Th e mean sedimentation rate in this interval is 11.3 cm/kyr. Magnetic pr operties and hysteresis ratios indicate that pseudo-single domain magn etite is the remanence carrier. Volume susceptibility (k), anhystereti c (ARM) and isothermal (IRM) remanence values vary by a factor of 3-4, well within the criteria usually cited for paleointensity studies. Na tural remanent magnetization (NRM) is normalized by ARM and IRM to acq uire the paleointensity proxy. Arithmetic means of NRM/ARM and NRM/IRM , calculated for five demagnetization steps in the 25-45 mT range, con stitute the relative paleointensity estimates. Some paleointensity low s (particularly those at similar to 40, similar to 120 and similar to 188 lia) are associated with directional excursions of the field, espe cially the event at similar to 188 ka (referred to here as the Iceland Basin Event) that constitutes a short-lived polarity reversal. For th e last 200 kyr, the records can be correlated with other high-resoluti on paleointensity records such as those from the Labrador Sea, Mediter ranean/Somali Basin and Sulu Sea, implying that the millennial scale f eatures are globally synchronous. A labeling system for paleointensity features is proposed that ties prominent highs and lows to oxygen iso tope stages. (C) 1997 Elsevier Science B.V.