Continental drift Continental drift Continental drift is the theory that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596. The concept was independently and more fully developed by Alfred Wegener in 1912, but his theory was rejected by many for lack of any motive mechanism. Arthur Holmes later proposed mantle convection for that mechanism. The idea of continental drift has since been subsumed by the theory of plate tectonics, which explains that the continents
Continental Divide of the Americas such as the International Hydrographic Organization add a sixth: Canada's Northwest Passage basin. Using just the five, there are four secondary continental divides and three secondary triple points, the two mentioned previously and a third near Hibbing, Minnesota, where the Northern Divide intersects the Saint Lawrence Seaway divide. Since there is no true consensus on what a continental divide is, there is no real agreement on where the secondary triple points are located. However, the main Continental Divide described in this article is a far more distinctive geological feature than the others and its two main triple points are much