Evaluation of some geotectonic hypotheses by paleomagnetism

Abstract

All available Carboniferous and younger paleomagnetic data (some 220 individual observations) have been studied and are presented by pole positions and isoclines, averaged over the geological period and continental block to which they belong (Plate I). In view of the growing evidence for global expansion, the data have also been worked to adapt them to globes of smaller size (Plate III). The paleomagnetic data show: (1) that continental drift must have occurred and (2) that large-scale movements in the alpine areas have taken place during some stage of the alpine orogeny. Paleomagnetic data as yet provide only two of the three parameters required to reconstruct exactly the ancient continental configurations; but these two parameters provide nonetheless a valuable check on continental arrangements as predicted in the various geotectonic hypotheses, and it is with this in view that paleomagnetic data are used in the present paper. The reconstruction presented has many affinities with the well-known drift theories, but is rather unorthodox in other respects; it tries to establish a connection between orogeny and continental drift, and takes into account first-order structural features such as the mid-oceanic ridges and large strike-slip faults.