PALEOMAGNETIC STUDY OF ODP LEG 119-KERGUELEN PLATEAU AND PRYDZ BAY

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ODP Leg 119 drilled at the Kerguelen Plateau in the southern Indian Ocean and Prydz Bay in Antarctica. Hole 745B on the southern Kerguelen Plateau gave the excellent reversal sequence during the last 6Ma including the Cobb Mt. event in the Matuyama chron and the unidentified subchron in the Gilbert chron. Limestone sequence at Hole 738C from Turonian to Santonian stage shows the low paleolatitude (54°S) compared with the present (64°S). This paleolatitude is nearly the same as the Tertiary paleolatitude estimated from VGP of Antarctica. The basaltic rocks below the limestone sequence showed two groups of magnetic inclinations around +50° and -70°. The magnetizations of the two polarities indicate that the eruption of the basaltic rocks occurred during a fairly long time. The large difference of the absolute inclinations suggests the possibility that the tectonic tilting has occurred in Hole 738C, near the southern end of the Kerguelen Plateau. In Hole 742C of Prydz Bay, glacial sequence down to 316 mbsf (meter below sea floor) was drilled. Magnetic susceptibility of this sequence showed a good correlation with the change of lithology. Magnetic inclinations of the sequence from middle Eocene to Oligocene showed the dominant normal polarity zone with several short reversals. It suggests that a large glacier complex existed in Prydz Bay during earliest Oligocene and possibly during late middle Eocene period.
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