Fig 2.

Paleomagnetic characteristic remanent magnetization directions from thermal demagnetization before (a) and after (b) unfolding. (c) Paleomagnetic pole (star) calculated from this direction data shown versus mid-Cretaceous poles of the North American craton (19). (d) Normalized estimate of precision parameter (K) for mid-Cretaceous North American poles (A–F of ref. 19) and the high Canadian Arctic (this work, assuming a 12° vertical axis rotation). Values shown assume various contributions of an octupole relative to the dipole field (G3). (e) Angular dispersion (S) of time-averaged VGPs and select data sets from the K-N Superchron (solid stars, Northern Hemisphere; open stars, Southern Hemisphere) shown with 95% confidence intervals (28). Also shown is fit of secular variation model (27) G to 0–5 Ma data (6) (solid curve) and 95% confidence interval (dashed curves). (f) Comparison of VGPs from the Cretaceous Canadian Arctic (normalized to 90° mean latitude) and Neogene lavas of Iceland (30, 31).