Résumé
Numerous observations of the magnetic field variations, uniformly distributed on the Earth's<br />surface for different time windows are needed to improve our knowledge on the inner-core dy-<br />namic. The first part of this work reports a paleomagnetic study, direction and intensity, carried<br />out on oligocene lava flows from the Kerguelen archipelago (49° 20'S, 70° 20'E) in order to im-<br />plement international databases. A between-flow angular standard deviation of 21.2 to 21.8°<br />from the geographic pole has been computed. This estimation of the oligocene paleosecular<br />variation agrees with McFadden et al. (1991) Model G for paleosecular variation between 22.5-<br />40 Ma. The 12 new paleointensity determinations reported are the first estimations obtained<br />for this archipelago with good technical quality. The mean VDM of 6.15+-2.1 10e22 increases<br />the mean oligocene estimate but is still lower than recent value ( 0.3 Ma), which seems abnormaly high.<br />Moreover, this work brings additional constraints to the geological researches carried out on<br />Kerguelen. We proposed a better location of the eruptive center for the different magnetic pro-<br />vinces and a detailed chronology of emplacement for a southeastern site by means of magnetic<br />fabric studies. Correlation of the polarity successions for fiv e sections with a global geomagne-<br />tic polarity scale allowed refinement of the emplacement time of these volcanic sequences and<br />consequently reevaluation of their extrusion rates.