Revised and synthetic apparent polar wander paths of the African, Eurasian, North American and Indian Plates, and true polar wander since 200 Ma

摘要: We have reviewed paleomagnetic data available for the Eurasian, African, North American and Indian plates over last 200 Ma. Selection criteria are those generally accepted, with an emphasis on evidence lack of remagnetization, accurate dating proper structural analysis. This results in 23, 35, 51 2 poles Eurasia, Africa, America India, respectively. believe that this limited set higher quality is more likely to reveal key features apparent polar wander (APW) paths than averaging larger sets involving less stringent selection criteria. propose describe revised APW paths, but importantly, we next use relative motion models transfer all a common reference frame. find good agreement between transferred data, when they averaged separately each plate independent 20-Ma windows. check consistency kinematic models, geocentric dipole hypothesis. Transferred from windows generate synthetic studied. These original (revised) only single plate. Moreover, both geographic time resolution improved (spatial confidence intervals order 5°). The display interesting features, such as previously ill-recognized loop Eurasia. Paleomagnetic hotspot compared, determination true (TPW) derived. significant TPW, amounting 20° TPW appears be episodic, standstill 180 110 There general previous study Livermore et al. (1984). correlate decreasing reversal frequency, ending Cretaceous Long Normal Superchron. Other periods fast would seem correspond increasing frequency. However, it suggested major hairpin at 50 Ma might collision India Tentative correlations core or mantle indicators can understood result couplings core, lithosphere, primarily related episodic evolution D″ layer.