| Summary: | The purpose of this paper is to review the progress made over the past four years in studies of Phanerozoic and Precambrian polar wander, with an emphasis on the contributions made by U.S. scientists. We perceive a general theme embracing the notion that the accuracy of cratonic "reference poles" and therefore of apparent polar wander (APW) paths is not as good as was generally believed four years ago. A renewed interest in research concerning cratonic reference poles is largely the result of paleomagnetic studies in orogenic belts, namely the western Cordillera and Appalachians of North America, the Andes of South America, and elsewhere which seek to document the existence or non-existence of displacements of suspect terranes (i.e., rotation and/or translation) with respect to their presently associated cratons. (Some of the results of this research are reviewed in this volume by Hillhouse and McWilliams). An important realization of which paleomagnetists have long been aware but which was demonstrated recently by a number of sobering examples for both the Paleozoic and Mesozoic APW paths for North America, is that the reliability of concordance/discordance parameters that define terrane displacement is dependent not only on the precision and accuracy of the individual paleomagnetic study, but also on the precision and accuracy of the appropriate cratonic reference pole.
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