Tehostekuvassa fysiikan laitosta etuoven suunnalta

1f. Paleomagnetism of Arizona dykes & sills

Participating scientists

  • L.J. Pesonen, prof. (emeritus)
  • L. Heaman (University of Alberta, Canada)
  • B. Shaulis

Project goals

The goal is to define whether the same asymmetry as seen in Lake Superior Keweenawan data (1.15 - 1.08 Ga) is observed in coeval Arizona dykes and sills. New datings will be carried out at University of Alberta, Edmonton, Canada.


Both N and R polarity dykes & sills are discovered with strong asymmetry. We now investigate whether this asymmetry is due to (i) age difference and therefore APWP (R considerably older), (ii) ND-field, or (iii) TPW.

Logan Loop (dashed line, with superimposed poles from the Grand Canyon (diamonds), poles from Central Arizona, and associated α95 (dashed ovals) cones of confidence. b) Labels of the Unkar Loop poles are reported after Elston et al. (2002)

Recent publications

  • Donadini, F., Pesonen, L.J., Korhonen, K., Deutsch, A., Harlan, S.S., 2011. Paleomagnetism and paleointensity of the 1.1 Ga old diabase sheets from Central Arizona. Geophysica, 47(1-2), 3-30.