SPATIAL LOGIC IN PALEOGEOGRAPHY AND THE EXPLANATION OF CONTINENTAL-DRIFT

The scientific methods employed in paleogeography have followed two distinct logics. Spatial logic accepts morphology, spatial distribution, and spatial association as primary evidence of earth processes that must be tested through process-oriented research. Process logic accepts contemporary knowledge about individual earth processes, synthesizes general theory, and proposes spatial tests. Wegener's argument for continental drift, based on spatial logic, was rejected by most scientists from 1912 to 1960. Arguments for sea-floor spreading and plate tectonics, based on spatial logic, were accepted by most scientists from the 1960s to the present. Since the 1960s, process logic has dominated the search for mechanisms causing plate tectonics. Extension of spatial logic in this research finds previously undocumented continental fits among South America and Africa, South America and North America, and North America and Australia. This evidence suggests a new theoretical model of continental drift and plate tectonics, with circular plate motion caused by thermal convection and lateral plate motion caused by gravity.