Continental drift Permian era but failing to account for glaciation in India, Australia and South Africa. Geophysicist Jack Oliver is credited with providing seismologic evidence supporting plate tectonics which encompassed and superseded continental drift with the article "Seismology and the New Global Tectonics", published in 1968, using data collected from seismologic stations, including those he set up in the South Pacific. It is now known that there are two kinds of crust: continental crust and oceanic crust. Continental crust is inherently lighter and its composition is different from oceanic crust, but both kinds reside above a much deeper "plastic" mantle. Oceanic crust
Big Drift Big Drift The Big Drift is in Glacier National Park, in the U.S. state of Montana and is an area along the Going-to-the-Sun Road where a large amount of winter snow can accumulate to depths of . Located immediately east of Logan Pass, the westerly winds push snow over the crest of the Continental Divide onto the eastern flank of a long arête which extends south from Pollock Mountain. West of the divide, this arête is known as the Garden Wall. As spring approaches, the region is surveyed by helicopter in preparation for snow removal that will be needed in