A determination of true polar wander since the Early Cretaceous
Abstract
An analyses of the displacement field of the lithospheric plates yields insignificant true polar wander since the Early Cretaceous. A general displacement field on a sphere can be decomposed into two parts: a part due to a rigid rotation and a remaining part of residual motions. It true polar wander had occurred, it would be observable as such a rigid rotation of the lithosphere. The remaining part of (higher order) residual motions are then attributed to 'continental drift'. Reconstruction of the positions of the plates from paleomagnetic and sea-floor spreading data is now possible and gives the needed displacement field of the plates. An analysis of this displacement field indicates that the amount of true polar wander is insignificant, as it generally lies within the uncertainty of the world average paleomagnetic pole used in the calculations. Thus, true polar wander is not necessary, at least for the last 115 m.y., to account for the apparent polar wander paths.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- May 1974
- Bibcode:
- 1974PhDT.........5J
- Keywords:
-
- Earth Axis;
- Lithosphere;
- Continental Drift;
- Earth Rotation;
- Geophysics