CONCLUSIONS

We provide revised magnetostratigraphic interpretations of paleomagnetic data from the three drift sites cored during Leg 178. We outline in detail the rationale for our interpretation, which is mainly based upon matching the pattern of the polarity zones recorded at the Leg 178 sites with the chrons of the geomagnetic polarity timescale. The revised interpretations are generally consistent with the biostratigraphic constraints, which on their own permit alternate magnetostratigraphic interpretations with the inclusion of one or two hiatuses at Site 1095 as discussed by Iwai et al. (Chap. 36, this volume). The magnetostratigraphic observations are, however, consistent with continuous sedimentation with decreasing sedimentation rates up section at Site 1095, a step decrease in sedimentation rates at Site 1096 from a mean of 181.0 m/m.y. before 2.581 Ma to 85.5 m/m.y. after, and a near-constant sedimentation rate of 68.9 m/m.y. over the interval cored at Site 1101. Our preferred interpretation includes no hiatuses at any of the sites.

We also provide a tabulated archive of more than 102,000 vector paleomagnetic measurements made at over 13,400 intervals along U-channel samples. Besides the raw data, we include the results from principal component analysis and stable end point determinations from these data. Similar data sets from shipboard measurements made on split-core sections and discrete samples are archived in Barker, Camerlenghi, Acton, et al. (1999). Together, these data provide the fundamental observations upon which our magnetostratigraphic interpretations have been based.

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