TEST FOR BIAS IN PALEOMAGNETICALLY DETERMINED PALEOLATITUDES FROM PACIFIC PLATE DEEP-SEA DRILLING PROJECT SEDIMENTS

Paleolatitudes determined from paleomagnetic study of azimuthally unoriented sediment cores recovered by deep sea drilling on the Pacific plate have been previously used in determining reference poles for the Pacific plate apparent polar wander (APW) path. From discordant paleoinclinations and corresponding paleolatitudes determined from these data, some workers have inferred tectonic tilting or large horizontal motion of some deep-sea drilling sites relative to other parts of the Pacific plate. Here the reliability of these paleolatitudes is evaluated by comparing them with paleolatitudes determining from a Pacific plate reference APW path determined from seamount poles, skewness and amplitudes of magnetic profiles across magnetically lineated seafloor, and paleocolatitudes from azimuthally unoriented basalt cores and from equatorial sediment facies. The reference APW path includes a new determination of the Early Cretaceous pole from several types of paleomagnetic data, which agree well with one another. Sediment paleolatitudes are found to be systematically less southerly than those predicted from the reference APW path. -from Author