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Jack Oliver is credited with providing seismologic evidence supporting plate tectonics which encompassed and superseded continental drift with the article "Seismology and the New Global Tectonics", published in 1968, using data collected from seismologic stations, including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
Drift migration known as a fallout, though in the latter case, it need not involve vagrant birds. An example would be an east wind in September blowing Scandinavian migrants such as bluethroats, wrynecks, and the continental race of robin onto the east coast of England and Scotland, leading to temporary concentrations of these species at headlands like Spurn. Drift migration Drift migration is the phenomenon in which migrating birds are blown off course by the winds while they are in flight. It is more likely to happen to birds heading south in autumn because the large numbers of inexperienced young birds are