Geomagnetic paleointensity and environmental record from Labrador Sea coreMD95-2024: global marine sediment and ice core chronostratigraphy for the last 110 kyr

Piston core MD95-2024 from the Labrador Rise provides a continuous record o f rapidly deposited detrital layers denoting Laurentide ice sheet (LIS) ins tability. The core also provides a high-resolution record of geomagnetic pa leointensity, that is consistent with, but at higher temporal resolution th an previous Labrador Sea records. Correlation to the Greenland Summit ice c ores (GRIP/GISP2) is achieved by assuming that Labrador Sea detrital layers correspond to cold stadials in the ice cores. This allows a GISP2 official chronology to be placed on MD95-2024 which is consistent with the inverse correlation between paleointensity and the flux of cosmogenic isotopes (Be- 10 and Cl-36) in Greenland ice cores. Synchronous millennial scale variabil ity observed from the MD95-2024 paleointensity record and a North Atlantic paleointensity stack (NAPIS-75) [C. Laj et al., Philos. Trans. R. Sec. Ser. A 358 (2000) 1009-1025], independently placed on the GISP2 official chrono logy [IC. Kissel et al., Earth Planet. Sci. Lett. 171 (1999) 489-502], furt her support the sediment to ice core correlation. High-resolution paleointe nsity and oxygen isotope records from the North Atlantic, Mediterranean, So mali Basin, sub-Antarctic South Atlantic and the relative flux of Be-10 in Vostok (Antarctic) ice core are used to derive a common chronostratigraphy that neither violates the regional (millennial) or global (orbital) scale e nvironmental stratigraphics. The resulting correlation circuit places the i ce core and marine records on a common GISP2 official chronology, which ind icates discrepancies as high as 5 kyr between the GISP2 and SPECMAP time sc ales. It further demonstrates that LIS instabilities in the Hudson Strait a rea are synchronous with cooling in the Greenland Summit ice cores and warm ing in the sub-Antarctic South Atlantic and in the Vostok ice core. Geomagn etic field intensity shows common global variance at millennial time scales which, in view of the out-of-phase interhemispheric climate variability, c annot be attributed to climatic contamination of the paleointensity records . (C) 2000 Elsevier Science B.V. Al rights reserved.