AN 84-KYR PALEOMAGNETIC RECORD FROM THE SEDIMENTS OF LAKE-BAIKAL, SIBERIA

We have conducted a paleomagnetic study of sediment cores obtained fro m the Selenga prodelta region of Lake Baikal, Russia. This record, whi ch spans approximately the last 84 kyr, contributes to a better unders tanding of the nature of geomagnetic field behavior in Siberia and is a useful correlation and dating tool. We demonstrate that the Lake Bai kal sediments are recording variations in the geomagnetic field. The d irectional record displays secular variation behavior with a geomagnet ic excursion at 20 ka and additional excursions appearing as large-amp litude secular variation at 41, 61, and 67 ka. Smoothing of the geomag netic excursion behavior occurs in Lake Baikal sediments owing to the intermediate sedimentation rate (13 cm kyr(-1)). The Lake Baikal relat ive paleointensity record correlates to absolute paleointensity data f or the last 10 kyr and to relative paleointensity records from the Med iterranean Sea and Indian Ocean for the last 84 kyr. This correlation suggests a strong global (i.e., dipole) component to these records and further supports the reliability of sediments as recorders of relativ e geomagnetic paleointensity. We show that a relative geomagnetic inte nsity stratigraphy has a potential resolution of 7 kyr by correlating continental and marine records. The geomagnetic intensity stratigraphy helps constrain the age of the difficult to date Lake Baikal sediment s.