Paleointensity across the reunion event in Ethiopia

Paleointensity experiments have been conducted on a volcanic series of 33 f lows which recorded the geomagnetic Reunion event. Successive determination s of absolute paleointensity from 20 Bows indicate that the Reunion event w ould actually be characterized by two successive periods of low field inten sity, with a total duration not in excess of 30 kyr. The first period has a mean paleointensity of 12 mu T and shows significant deviations from initi al reverse polarity but no signs of fully normal polarity. It is followed b y field recovery, then a decrease prior to the second directional episode. The second period has a mean paleointensity of 17 mu T and is associated wi th full normal directions, and thus likely a dominantly dipolar configurati on. These results are compatible with a simple 'earthlike' magnetic field m odel with a large decrease in dipole field strength which yields local emer gence of relatively stronger non-dipole components. Field characteristics f rom this configuration would be different at different locations and could explain the variability of the paleomagnetic records collected around the w orld. We propose that the absence of field recovery following the event is responsible for not leading to a durable polarity interval. (C) 1999 Elsevi er Science B.V. All rights reserved.