Abstract

To test the ability to correlate sediments in deep ocean basins, 5 piston cores were taken from one station on U.S.N.S. Eltanin cruise 44, in one of the deepest and flattest regions of the Wilkes Abyssal Plain off East Antarctica. The 5 cores are characterized by interbedded siliceous ooze and terrigenous turbidite mud beds. The siliceous ooze is characterized by burrow mottling and high (90 to 95 percent) diatom and radiolarian content. The terrigenous mud beds have sharp basal contacts, lack evidence of burrowing except in the upper 10 to 20 cm, and are 20 cm to 2.5 m thick. Detailed examination of each core using smear slides at 10 cm intervals and examination of the diatom assemblages show that several major zones in the cores can be correlated with confidence. Correlations from one core to another were made using the relative stratigraphic position and sequence of pelagic and turbidite zones, and also by using three major diatom assemblage zones: the Nitzschia kerguelensis zone, the Rouxia sp. zone and the Actinocyclus ingens zone. Not only could major pelagic ooze and turbidite zones in the five cores be correlated over the short distance at the drift station, but they could also be correlated with zones found in a sixth core taken 55 km away. Rates of sedimentation for the pelagic zones are 1 cm per 1,000 yrs, and total sedimentation rates are 5 cm per 1,000 yrs.

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